stunthanger.com
Electric Stunt => Gettin all AMP'ed up! => Topic started by: Crist Rigotti on February 11, 2009, 11:01:54 AM
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Well I started on my 570 sq inch profile electric stunter last week. Here is a picture of what I accomplished by Sunday night. This week I added the Warren Truss to the flaps.
I'm planning on using a Scorpion 3020-890, a CC-45 ESC, JMP-2 timer, 4S2P 3400mah battery, Scorpion 2" metal spinner, and Xoar 12x5 electric prop.
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Looked at the pdf--there's nothing th'air' in that fuse!
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I changed the pdf to a jpg.
Somebody said air is lighter than balsa!
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I changed the pdf to a jpg.
Somebody said air is lighter than balsa!
I'm guessing no 'Ground Rounds' will be allowed with this plane.
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I'm guessing no 'Ground Rounds' will be allowed with this plane.
I hope not! It has me thinking what would happen to the electrics. I'm hoping the ESC senses all is not well and shuts down before the smoke rises!
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I changed the pdf to a jpg.
Somebody said air is lighter than balsa!
Do planes built from pdf's come out lighter than those built from jpg's ?? LL~
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Do planes built from pdf's come out lighter than those built from jpg's ?? LL~
Naw, its the other way around, remember pdfs are made out of Adobe... (groan) H^^ ;D
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Very funny fellas! Get your laughs in now, because you'll be crying at the circles! na# na# na#
I'll keep ya updated on my progress.
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OK I'll be serious (sorta) That IS a very good looking set of airplane parts you have there. Must have been difficult keeping them from floating away while you took the pix. Couple questions about the fuse:
* It looks like you are planning on a front mount? with a nose ring behind the spinner?
* Are you going to sheet the fuselage or just cover it?
Looks to me like you are going to have a very light airframe, a strong motor and a lot of electrons to burn in those new packs.
Good luck and keep it going!
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Dennis,
I weighed the wings so far and they weigh 7 oz which includes the tip weight box, cover and screw. They should come out finished with Monokote, flap horn, pushrod, and hinges at 11 - 11 1/2 oz. I used 3/32 balsa for the Warren Truss work on the flaps and elevators. I could of used 1/16, but I get tired of repairing the 1/16 from my heavy fingers. :)
1) Front mount, but no nose ring. What you see is a ply insert between the motor mounts to tie the front end together. Some on the forums think it is a waste of time, I don't. The front motor mount will be something special. Stay tuned! :##
2) The fuselage will be sheeted with 1/16 7# balsa on each side. The width will be 3/4 overall with the fuselage tapered to 1/4 from the stab hinge line to the tailpost. Hence the solid balsa. The plane will be all Monokote. No worries of oil and a light finish to boot.
The battery will sit inside of a pocket and the ESC and timer will be like on my Primary Force. My goal is 48 ounces. It looks like so far I'll beat it. The stab will have .25-.5 degrees of positive incidence, the motor will have 1 degree of down thrust and 2 degrees of right thrust to begin with. There will be a scoop on the inboard side. If you look closely you'll see it. It serves 2 purposes. To help cool the motor and I don't like a spinner overhanging a profile inboard side. The plane won't need a tripler and a tripler will make it a little more difficult to cover, so why bother? The spinner arc will be within the scoop outline. :)!
It's made so if I want to run a 3026 motor I can. Possibly do some testing in prepartion for a full up electric stunter next year.....you've been warned! LL~ LL~
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The wing and stab are covered and the fuselage is built. It has to be sanded and shaped. It came out very stiff and rigid. I used basswood for the engine bearers. Enjoy the pics.
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Looks good Christ!
Nicely thought out installation, too.
Dean P.
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Fantastic - still looking light and strong. Looks like ou'll have it ready for the long-rumored flying weather that's supposed to happen some day...
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Hey Crist: Nice wing tips LL~ LL~ LL~ Just wondering how you attached the wing ??? ??? ???
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Lee,
The wing was just slid in for the pictures.
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I am envious that you don't have to spend much time on thinking about the color scheme!
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I am envious that you don't have to spend much time on thinking about the color scheme!
Yeah, you would think with all the extra time I have I would be thinking about ESC's and stuff. I'll leave that stuff up to you. H^^
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Crist,
Great looking ship!! One suggestion that has worked well for me is to open up the front of the simulated cowl and drill some holes through to the motor compartment. This helps with the motor cooling if you have a spinner. On mine ship the fuse is hollow and I was able to inset the ESC and Timer. The open cowl allowed cooling air to blow over these components also.
Best, Dennis T
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Dennis,
I have planned a scoop on the inboard side to bring air over the motor. Just haven't gotten around to cutting the hole yet in the fuselage. See post #9 my reply to Dennis Adamisin.
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Guys,
While we are on the subject, look at the last picture where I have a side view of the airplane. Is the fin/rudder the "correct" size? I admit that I'm never sure if it should be taller, or wider, or more slope to the LE, more slope to the TE, etc. What's your opinion?
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Crist,
Fin/Rudder is fine, in CL it's not a big deal, not even needed. Look at bob Hunts Genesis also the Olympic. Fin/Rudder are mostly for looks cause that's what we expect.
Best, Dennis
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Thanks Dennis.
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The fuselage is ready to cover. I soaked the edges with CA before I sanded a small radius in them. I'm amazed how much stronger the wood gets. I did that so I can control the radius while sanding and to add some "impact" resistance. I'll "wood peck" the fuse then cover it with Monokote. As you see it, it weighs 6.4 ounces. The slots are for the Velcro battery straps from Tanic.
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Looking good Crist,,
keep up the pictures,, looking forward to seeing how this one performs for you
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The fuselage is covered with Monokote. It added only 17 grams. When the Monokote matching Nelson Paint arrives, I'll paint the battery and engine compartments. On to covering the flaps, then assembly.
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Hi Crist
Archie & I were just talking about you - and wondering if you got-er-done yet - man you are getting close! Its looking great too.
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Crist,
Looks great. Cant wait to see it done. This is going to be a great year for E-Cl. Do you have a projected total weight yet?
William
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William,
48-50 ounces. 570 square inch wing area.
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Glued the wing and stab in tonight. Slowly getting there. Sorry no pictures tonight. Maybe some tomorrow.
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Glued the wing and stab in tonight. Slowly getting there. Sorry no pictures tonight. Maybe some tomorrow.
TEASER! ;D
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I applied the microballoon and epoxy fillets tonight on the wing and stab. I also made another set of elevators that are heavier. I'll either use the light set or the heavy set when the plane is complete to balance it out where I want to start at (23%).
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Sweet.
What are you planning for power and energy?
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Scorpion SII 3020-890 and my 4S 3400mah battery, CC-45 ESC and a JMP-2 timer and prop TBD! :##
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Crist,
it looks really clean, Best of luck with it.
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Well boys & gurlz looks like Crist is ready to say good bye to all those greaser airplanes!
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Well remember, Randy Gifford is one of our prominent judges around here, so Crist will need to do something to placate her husband if he is to be successful!! LL~
Just in case it isn't obvious, the above comment is definitely tongue-in-cheek wrt Randy's objectivity. But it is difficult to keep concentration with Russ jumping up and down #^ in the downwind circle position!
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Crist,
I am working on a solution to this problem as I too have some old school judges that prefer the smell of castor while they are working. I am almost done with my electrically fired castor smudge pot. This device is run with a ztron V.4 timer, Lipoly batteries, and a small container filled with sig castor oil. It has an element that heats up and disperses the castor so the judges can catch a whiff of the sweet smell while you fly around making no smell,, It will be remotly activated by your arming switch on the airplane and timed to quit the same time your electic motor quits,, now I only need to tie it into a surround sound system to generate the engine noise and we will be set!!! VD~ S?P
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Crist,
I am working on a solution to this problem as I too have some old school judges that prefer the smell of castor while they are working. I am almost done with my electrically fired castor smudge pot. This device is run with a ztron V.4 timer, Lipoly batteries, and a small container filled with sig castor oil. It has an element that heats up and disperses the castor so the judges can catch a whiff of the sweet smell while you fly around making no smell,, It will be remotly activated by your arming switch on the airplane and timed to quit the same time your electic motor quits,, now I only need to tie it into a surround sound system to generate the engine noise and we will be set!!! VD~ S?P
I just stick out my tongue and give my rendition of a 4-2-4 run! :P
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yeah but do you hit the lean portions at the right time?you konw some of them judges listen to the motor to tell what the plane is doing, I am going for the high rpm two stroke engine run, lol
LL~ LL~ %^@
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Hmmmm
How about the sounds similar to a DynaJet makes when its starting???? Can skip the castor oil smell too. Just say its...Kerosene
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You guys just hijacked my thread! mw~ mw~
Tomorrow I'll cover the fin and rudder and glue in the fin. I made a new rudder out of solid balsa tonight. I can use the weight in the back. :)
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You guys just hijacked my thread! mw~ mw~
Tomorrow I'll cover the fin and rudder and glue in the fin. I made a new rudder out of solid balsa tonight. I can use the weight in the back. :)
Well it's always fun to have fun at your expense!
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Well it's always fun to have fun at your expense!
..and we are collectively excited about the new bird. ROCK ON Crist!
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actually if you worked faster, and posted more pictures we wouldnt be so tempted to hijack your thread,,,, #^
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You guys just hijacked my thread! mw~ mw~
Tomorrow I'll cover the fin and rudder and glue in the fin. I made a new rudder out of solid balsa tonight. I can use the weight in the back. :)
Crist -
It may have been lost in the "Crash of '08", but I can't find the link to where you
got your batteries -
Could you repost it?
TIA
Mike@
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It went something like this:
I just received 4 packs from PolyNoOne. Wow!, very good quality. All four packs either weighed 312g or 313g. Now that's good quality control. They were shipped FedEx and I received them in 2 days. They were packed very well and arrived in excellent shape. Every cell measured 3.85v. These packs were made especially for my control line needs and are 4S2P 3400mah 20C packs. From the time PolyNoOne received payment till they were at my doorstep was 16 days. BTW, I put on the EC3 connectors.
This was my post on RCGroups Batteries Forum.
http://www.rcgroups.com/forums/showpost.php?p=11311966&postcount=244
http://polynoone.com/main.php
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The Nelson paint arrived today. I used some white right out of the bottle to brush touch up my hinges on the flaps. Looks like it will work real well. I'll post more on what I find when I paint the battery and motor compartments. Also I have to touch up the fillets too. Stay tuned. #^
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The battery and motor compartments are painted with Nelson Paints. I used a brush and it came out OK. I touched up the fillets too. It took 4 or 5 coats. The paint isn't as shiny as Monokote so I'll put a coat or 2 of the gloss clear later. Making the motor mounts and the elevators are ready to cover. It looks like it'll come out to 49 to 50 ounces.
BTW I didn't get to work on the plane last weekend due to family matters......my daughter gave birth to an 8 lb 21 inch baby boy! I'm a 3 time grandpa!
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The battery and motor compartments are painted with Nelson Paints. I used a brush and it came out OK. I touched up the fillets too. It took 4 or 5 coats. The paint isn't as shiny as Monokote so I'll put a coat or 2 of the gloss clear later. Making the motor mounts and the elevators are ready to cover. It looks like it'll come out to 49 to 50 ounces.
BTW I didn't get to work on the plane last weekend due to family matters......my daughter gave birth to an 8 lb 21 inch baby boy! I'm a 3 time grandpa!
CONGRADS Gramps! CLP** (PE**) HH%% Better finish up the 570, you only got 3-4 years to get that grandson's first trainer built!
I'm still a rookie - grand daughter turned one last weekend. But she is training me good!
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I hear you on the family stuff, my Grandaughter (18 months) is visiting for the week. work on my airplane? NOT LIKELY. though she does like to look at my planes and point, saying "pane, pane,," yeah if only she knew how appropriate that is,, snicker,,
grandkids are pretty cool, we have the patience to enjoy them and not get frustrated, PLUS they get to go home before your ready to pull your hair out,, #^ n~ LL~
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Congratulations Crist!!! Best of luck to you and your family. I'm probably the baby out here so I have a few years to wait for that pleasure.
William
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OK, time to let everyone in on my motor mount. The motor is front mounted and rear supported. I made the mounts from 2024-T3 .063 aircraft grade aluminum. The rear is supported by a flanged bearing that is press fit into the rear support. Now these are the prototypes and I'll make another set that on the front mount the motor will sit down closer to the fuselage about 1/16 or so, do away with the cooling hole by the wires and raise the other cooling hole slightly to align with the one on the motor. I'll also use some socket head bolts to hold the motor to the front mount. I haven't checked how much drag the extra bearing puts on the system, but I will when I do the final assembly. The mounts weigh just 8 grams and the motor is very rigid. More so than just front mounting it. Enjoy the pics.
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Great stuff Crist. The mounting idea is right on the money. I really can't wait to see how this thing goes.
By the way, I work in sheet a metal fabrication company and when you get a design you like, we have (2) lasers and (4) press brakes. I think an electric mounting system for a profile would be a very marketable. Your idea is right on.
We are desperately awaiting liftoff!!
Take care!!
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That is a sweet mount!
And congratulations on being a GrandDad.
However it does sound like you are becoming a little wimpy---slowing down your building and all. TreeTown "legend" Jerry "Who" Meyer, when told by his daughter of her upcoming marriage, told her "great, but I'll at the NATS!". LL~
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Crist,
I like your mounting idea, right along the lines I have been thinking too. Of course being me, I am thinking the same Idea only backwards,, though after seeing how clean your installation is. I may be changing my mind on that one too. OBTW I like the prop!
I should be getting some flights in this weekend, making a trip to the west side to drop of my grandaughter, I have the XOAR all mounted up on my profile for some test time.
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Great stuff Crist. The mounting idea is right on the money. I really can't wait to see how this thing goes.
By the way, I work in sheet a metal fabrication company and when you get a design you like, we have (2) lasers and (4) press brakes. I think an electric mounting system for a profile would be a very marketable. Your idea is right on.
We are desperately awaiting liftoff!!
Take care!!
Put me down for two - 1 with a 4mm ID bearing and one with a 5mm ID. Invoice me through Paypal or send me a couple of prototypes to test. TIA ---
Fantastic bit of design, Crist. And congrats on the new family member -- we were just presented with our 8th grandson last week, to go along with our 3 grand-daughters - I haven't had him out to the field yet, but soon -- very soon.
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Hey Crist, the plane is looking good, can't wait to see it out at Mt Joy. Oh... BTW remember not to let the Grandkids play with Sticks, 2X4's 2X2's etc around the planes LL~ LL~ LL~ LL~ And congrats on the new one.
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Latest update. The pushrod cover and scoop are on. The final version of the motor mount has been fabricated and works very well. I have to cover the elevators, and apply the "ink" lines on the flaps and elevators, hinge the elevators, then mount the motor and electronics. Install the controls and do final set up. Getting real close.
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Crist,
What is the function on the inboard scoop? Grab up any escaping electrons and put them back into the battery?
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It prevents the spinner from "hanging" over the inboard side of the profile. y1
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Well guys, not yet. Very close though. Got the motor, esc, and timer mounted. All that's left is to "ink" the control surfaces and hook up the controls, and seal the flap and elevator hinge gaps. I'm not really satisfied with using velcro mounting the ESC. I'm thinking of using the strong "velcro" that is more like a plastic. Any ideas are welcome. It looks like it will just be under 50 ounces and a balance at 24%. If I want the CG forward, I'll use a lighter set of elevators and end up with a lighter airplane. Tomorrow I'll post a set of pictures of the completed airplane.
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Bob,
I'll let everybody know how it works out after flying it. Your idea for a full bodied version looks good. Yeah, ECL just keeps on getting better!
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It's ready to go....almost! I have finished it except I want to put on the lighter elevators. They are 1/2 ounce lighter. With the heavier elevators, as shown in the pics, it weighs 50 ounces almost exactly, 1418 grams. That's with a 1 ounce of tip weight. Right now it balances right at 25% and with the lighter elevators it will balance at 22% and weigh 49 1/2 ounces. I want to start out with the forward CG then work back. The specs are:
570 sq in
54 WS
27% tail volume
Scorpion SII-3020-890 front mounted and rear bearing supported
PolyNoOne 4S2P 3400mah battery
Castle Creations Phoenix 45A ESC
JMP-2 timer
Scorpion 2" spinner
Xoar 12 x 5 E Prop
Foam wing
All Monokote finish
Nelson Paints for touch up
4" bellcrank set forward of the CG
Ball link and carbon fiber pushrods
Set up for a Rabe Rudder or fixed "adjustable" rudder
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I also found some heavy duty "velcro" to hold down the ESC. It is called 3M Dual Lock. It's low profile and the part number is SJ-4570. I got a yard off of eBay. I'll let everyone know how well it works out. The engaged thichness is like a 1/10 of an inch!
http://www3.3m.com/catalog/us/en001/electronics_mfg/esm/node_TZHTRGXH0Xbe/root_GST1T4S9TCgv/vroot_DPB1Q1MJ7Nge/gvel_LPQT5P05BQgl/theme_us_electronicsesm_3_0/command_AbcPageHandler/output_html
Search eBay for SJ-4570 Dual Lock and you'll find where I bought a yard for $8 shipped.
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Good luck with the plane!!! It really looks great. I'm looking forward to hearing how it flys!!! Maybe you will do better than me and not have to wait so long to get it flying. The NYC weather just wont cooperate. Next week I will be away so who knows when for me? Let us know how those batteries work out. I have been following the thread on RC Groups and they look promising.
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Crist , be sure and give us a ring when you bring it to Mt. Joy, as long as I'm not working I'll come out. Looks real good
Oh where did you get the spinner and prop ??
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I will Lee. Maybe Saturday early.
I got them from RC Dude
http://www.rcdude.com/servlet/StoreFront
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Looks like Saturday will be test flight day! A full report to follow.
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Well Saturday it flew! The motor mounts worked very well. My Eagle Tree FDR wouldn't download any data so I don't have any flight graphs to show. When I got home I ended up reloading the software and it's working now. So next time out I'll have some graphs. Here are some numbers from what I could get from yesterday. The battery mah was what the charger put back in.
Xoar prop 12 x 5
10600 rpm
5.4 laps
60 foot lines eye to eye
1942mah
The rpms are too high figuring that max we want to be about 75% (9600) of max rpms (12,800).
Xoar Prop 12 x 6
9600 rpm
5.1+ laps
60 foot lines eye to eye
2521mah
2412mah
2388mah
2022mah
The 2022mah was the last flight of the day and I'm not sure why it was so low. The wind was the calmest of all the flights too! I'll do some more recording next time out.
Line tension was excellent with the 12 x 6 prop and very good with the 12 x 5 prop. I didn't get the chance to try the APCE 12 x 6 prop up against the Xoar 12 x 6 but will next time out. If the APCE 12 x 6 works well, then I'll try the reverse rotation version.
Spent most of my energies working on getting the airplane trimmed out and the way I want it to feel. Looks like I have plenty of power and battery to spare.
We're on our way!
PS Dean,
Looks like your formula of 50 ounces X .7 = 35 / 14.8 volts = 2.4ah or 2400mah is right on the money.
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Crist,
great news, glad shes in the air. I can hardly wait to see a back to back with the APC. Maybe on the last flight your motor reached the broken in point like a glow motor when the fuel economy comes in? lol,,,, LL~
Keep us posted, very interesting project to be sure.
alas my elect situation is momentarily stalled trying to get ready for next weekends contest... soon to continue
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Looks good in the air Crist. Also looks real close to the hangar, Floyd takes good pics. Wish I could have made it.
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Lee,
Looks like Wednesday evening will be the next good day for flying.
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I also found some heavy duty "velcro" to hold down the ESC. It is called 3M Dual Lock. It's low profile and the part number is SJ-4570. I got a yard off of eBay. I'll let everyone know how well it works out. The engaged thichness is like a 1/10 of an inch!
<snip>
Search eBay for SJ-4570 Dual Lock and you'll find where I bought a yard for $8 shipped.
Well the Dual Lock worked very well in regards to not being so wobbly. It worked quite well. I'm still looking for something that has more grip to try my idea for a one handed disconnect. Might just have to build a low profile "shelf" and zip tie it in place.
4-19-2009 Update:
I did build a shelf to mount the ESC. It consists of a piece od 1/16 birch ply about 1 (h) x 1 1/2 (w) with 1/16 basswood on the backside with 3/16 gaps for the tie straps. Touched it up with Nelson Paints and now the ESC is mounted firmly. Do you think I should put a thin piece of foam between the ESC and shelf for some vibration dampening?
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Congrat's Crist!! Glad you were able to get her airborne. So now that you have it trimmed, how does she fly? LL~ LL~
I am glad to here that the Xoar props worked out. It's nice to know that we have some more OTC options for electris stunt. I look forward to seeing the Eagle tree data.
Take Care!!
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Even though I am away,I made it to a PC today and have to say congratulations on you successful first flights. How did those PolyNoOne batteries feel. I know you didn't log these flights.
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Way to go Crist! Thanks for posting the data that you have so far. H^^ CLP** BW@
Looking forward to seeing the 570 do its thing.
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Even though I am away,I made it to a PC today and have to say congratulations on you successful first flights. How did those PolyNoOne batteries feel. I know you didn't log these flights.
Barely warm at all.
Thanks William, Archie, and Dennis.
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Barely warm at all.
Thanks William, Archie, and Dennis.
Crist,
I bet you can attribute your good efficiency to that V2 Scorpion motor! y1
I really do like your motor mount. How hard was it to mount so that the rear (I think) bearing didn't bind--I know you would drill the back holes after tightening down the front mount with motor in it, but did you need to shim the height at all?
Alan
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Alan,
Yeah, the new V2 could be the reason. So far I like it. Runs very smooth.
I designed the front mount to have the center of the shaft even with the outboard edge of the fuselage. The aft mount is 1/16 "into" the fuselage thus giving me 2 degrees of right thrust. Also the center of the rear bearing is 1/32 high giving me 1 degree of down thrust. I mounted the front mount at an angle that was even with the front nose ring thus giving me the 1 degree down thrust. Then I added the aft mount and it just barely touched the fuselage. I lined up the mount for the required down thrust and tweaked the mounts for the right thrust and it tightened down just fine. I ran the motor with no prop and monitored the current draw then I loosened the aft mount and saw no change in current draw. Tightened the mount and the same thing.
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Well Saturday it flew! The motor mounts worked very well. My Eagle Tree FDR wouldn't download any data so I don't have any flight graphs to show.
<snip>......
Xoar Prop 12 x 6
9600 rpm
5.1+ laps
60 foot lines eye to eye
2521mah
2412mah
2388mah
2022mah
The 2022mah was the last flight of the day and I'm not sure why it was so low. The wind was the calmest of all the flights too! I'll do some more recording next time out.
.......<snip>
Crist,
Out of curiosity, were the packs all from the same manufacturer? The reason I ask is that a pack with lower internal resistance will need less total current than one with a higher resistance. The reason is of course the output voltage at the battery plug will be higher, and so you will get the same watts at a lower output current.
Also maybe you made a flight adjustment (leadouts for example) which may have aerodynamically cleaned up the plane.
Hope the Eagletree works next time. Same thing happened to me last year, for some reason the EagleTree refused to take data on one of my early flights with the Nobler.
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Alan,
Yes, from PolyNoOne. I did make a leadout adjustment but using another pack. I have a total of just 2 cycles on each pack so far. I'll keep my eye them to see if any of the batteries perfrom better than the others. Wednesday evening is the next flying day.
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Glad to hear it, Crist!
take care,
Dean
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OK guys, got out tonight and did some more prop testing. The Eagle Tree performed well. I tested 3 props dialed in to give me @5.2 sec laps. I tested them flying about 70 seconds each time. They were:
Xoar 12x6 428ma @350W
APCE 12x6 377ma @300W
RSM 12x5.5 419ma @360W
Here is each graph:
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Wow, thats really nice data.
Also it looks like your total power needs for the last flight with the RSM prop are down in the 2200mAHr range--like the last flight from the previous outing.
The APC appears to win the level flight power efficiency of the three props. What is also interesting is that it is running 1k rpm down (8600) from the XOAR 12-6 prop (9600) for the same lap time. Now it would be interesting to see how you think it feels in the maneuvers compared to the XOAR (or the RSM for that matter). That of course is subjective, but I trust your opinion!
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Alan,
I'll need to do more testing. The APCE 12x6 is definately has a higher "effective' pitch than 6 by evidence it runs at a lower rpm for the same 5.2 sec lap. The RSM prop is very good! I thought that it would get your attention!
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Alan,
I'll need to do more testing. The APCE 12x6 is definately has a higher "effective' pitch than 6 by evidence it runs at a lower rpm for the same 5.2 sec lap. The RSM prop is very good! I thought that it would get your attention!
Yes but it is the most power hungry of the lot!
I know the APC 12-6 effective pitch is higher than 6 inches. I fly at 54 mph with my Nobler with the APC12-6 at 8000 rpm. The "pitch speed" at 8000 rpm is 45 mph!. That's why it pays sometimes to ignore what is on the prop! I haven't actually tried to measure the "pitch" with my Prather gauge. I just assumed it has something to do with the airfoil of the prop.
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I ordered a couple of 13 x 6 Xoar props to see how they will do. I like the 9600 rpm because it is 75% of max rpm. Pretty close to where we want to run our motors.... right? I might end up trimming them down to get the total current draw to where I want it. About 2600 to 2700mah.
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I ordered a couple of 13 x 6 Xoar props to how they will do. I like the 9600 rpm because it is 75% of max rpm. Pretty close to where we want to run our motors.... right? I might end up trimming them down to get the total current draw to where I want it. About 2600 to 2700mah.
Well there are two things. The 75% comes from the fact that you want power in the overheads so you need to have some leeway there. Also you need to include the fact that the battery is at a lower voltage at the end of the flight, when you are doing the overhead 8 and clover. I was never sure what people are using for the battery voltage when they make that calculation (I actually use the nominal 3.7V/cell I think).
Secondly, if you are using much less than the 75%, you begin to abuse your battery a bit because it means it is supplying current for not much over 1/2 the total PWM update period.
With regard for the first point, one thing to note is that 75% throttle isn't 75% power, more like 56% available power, since not only is the effective voltage ~75%, but also the current flowing, so the product of the two (=power) is closer to 56% (this is rough and not exact because of other factors). Since I need about 30% extra power in the overheads, I think I could actually use a larger # than 80%. But usually this advice is given to people just starting in electric, and it is always better to err on the side of being conservative than near the cutting edge (where sometimes you end up bleeding--and that makes bad press if it happens to a newbie!)
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Alan,
The 75% number came from a post a while ago I think from Dean explaining ECL systems. He said, if I remember right, that he and Bob Hunt kept increasing the the motor rpm till about 75% showed to be the most efficient. When I talk about 75%, I mean 75% of max rpm figuring the KV and battery voltage. With a KV motor of 890 and a 4S battery voltage of 14.4 came out to 9612. That's what I'm shooting for. Then running the 9600 rpm I'll adjust the prop to bring up the total mah used to 2600-2700mah.
From what I have gathered from reading some other forums, when running at 75% rpm, the amp draw is really about 60% of the continuous amp rating. The 3020-890 is rated at 45 amps continuous and at 75% rpm will be giving me about 28 amps. These numbers all fall within where I want to run my setup. y1
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Crist,
You are right. 75% of the no-load rpm isn't 75% throttle (duh.....). BTW, my 75% rpm point is 9770 rpm, and I fly at 8000. I think the 75% isn't mainly an efficiency thing, but really is to make sure you can hold your rpm at the desired setting throughout the flight. Less rpm is also ok. I would agree the motor, battery, and ESC would be happier at 75% rather than 60% for example, but I think you gain with prop efficiency with a slower turning prop. So the total system efficiency has a broad maximum--I am not sure where it is exactly--it probably doesn't matter that much. But in any case, efficiency isn't everything, and if you are happy, and you have the battery energy, then you are ok!
But I was thinking about a calculation I made using my motor parameters. I think I posted the plot in the thread on propellers. I'll post it again (you lucky dog!). It shows, that I am flying my level laps at 75% throttle (you see the 70%, 80%, 90%, and 100% throttle plots for power in and predicted power out). My maneuvers are occurring at 80% full throttle (based on 4x3.45V being applied voltage--I think this is the voltage I see near the end of my flight on my EagleTree ). My working region is the vertical red line at about 8000 rpm. So when I saw your 75% number, my mind jumped to the wrong conclusion!
Oh well, senility is setting in :'( .
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Alan,
Yeah, total system efficiency has a broad maximum. I'm trying the lower pitch route first. I know the prop says 6 pitch but the APC12x6 seems to be higher. The reason I'm trying the lower pitches is seeing if that route does reduce wind up. I know it does for nitro powered airplanes. I'll use whatever prop/rpm that gives me the line tension I'm looking for and little or no wind up in the wind. One thing for sure, there are certainly a lot of prop/rpm combos to try.
Seeing I have a 3400mah battery, which seems to be plenty, I want to use all of the 80% rule-of-thumb capacity for the performance I need. No sense leaving some performance on the table. Tonight I'll be out along with Saturday morning doing some more testing and trimming. Looks like a couple of good flying seesions are here. I'll post some more graphs Saturday afternoon.
It'll take me a bit to figure out your graph. Thanks for the post.
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Crist,
I have found that the APCE 12x6 is equivalent to about 1/2 pitch higher then the stated pitch because of the undercamber. I have depitch mine to 5" on the pitch gauge and run at 9000 rpm fixed mode, on 65' lines it gives me a 5.0 lap time. I have also tried one of the APCE 12x6P pushers and reversed rotation of the motor (switch any two motor leads) and depitch it to a 5" (you can reverse the swing arm and gauge plate on the prather then clamp the swing arm at the desirered pitch and you can set the blades) also and it hits the same lap time at the same 9000 rpm.
If you want line tension in the outsides then give the pusher a try. The square eight, vertical and overheads for me feel much better. You will have to do some re-trim to get the full benefit but you can get a pretty good idea by just putting one on and flying.
Best, Dennis
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Here is today's graph. I like the Xoar over the RSM prop. My 13x6 Xoar props arrived in the mail after flying this morning. I'll try them next time out. Also I'm going to try an APC 13x4 repitched to 5 like I used last year but not cut down to 12 inches. The total mah is 2267 and is pretty typical for this prop at 9600rpm. Still plenty of power left to get to 2700mah!
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Here is today's graph. I like the Xoar over the RSM prop. My 13x6 Xoar props arrived in the mail after flying this morning. I'll try them next time out. Also I'm going to try an APC 13x4 repitched to 5 like I used last year but not cut down to 12 inches. The total mah is 2267 and is pretty typical for this prop at 9600rpm. Still plenty of power left to get to 2700mah!
When you say "like", what do you mean? I am guessing you feel like it is handling the overheads better. Just curious.
Also, of course it isn't necessary to waste battery power! Just think that it will take you less time to recharge it, and most likely the battery will give you more flights. I think if you go to the larger diameter prop, it will end up spinning slower and actually save you energy! If you want to waste power, put on a 9-4 prop and spin the heck out of it (not sure if you can get enough rpm with your motor kV though!).
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Crist
GREAT work and thank you for reporting it all!
I think you might be on the wrong track for the EFFICIENCY theme tho. It looks like you are trying to find the prop that uses the most energy (i.e. increasing battery usage to 2700 mah) to accomplish the task - that is to fly the Resolve-570 through a pattern. Using MORE power to accomplish the same set of work is LESS efficient. Of course the big question is "What prop FLIES the best?"
The approach of using larger diameter and lower RPM seems responable, however, according to generic "fan laws":
* Power required increases as the 3rd power of RPM - however
* Power required increases as the 5th power of DIAMETER
That suggests that increasing the diameter is the wrong way to go to increase efficiency unless there is a very large reduction in RPM to offset it.
The "Swinger" you saw me fly at FCM last year used around 1800-1850 mah per flight: 560 sq in, 50 oz, 61' lines, 5.1 lap times using a 10x5 APC-E. In short the Swinger physical dimensions are in the same ballpark as the Resolve-570, but seemed to use less power.
All of this: a long and windy way of asking that you also try a SMALLER prop, like the 11x5.5 APC-E, probably at around 9500 RPM to achieve your goal. THen try a 10x5 (if you have enough kV) just to finish "mapping" the power optins like Alan's chart.
I test flew the Swinger with a 3000mah battery. When it was obvious that this was more battery than needed I switched to a 2500 for a roughly 2 oz weight save. Next time out I want to try the 2350's, then see if I am brave enough to go to 2100's - but that will be cutting it a bit fine.
Another way to use more battery: go to longer lines and a little more RPM to maintain lap times....
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Alan Dennis,
What I like in a prop is diameter. I'm trying to run as minimum a pitch that I can at 9600 rpm which I believe is the best rpm to be running my set up. So I'm trying to get the largest diameter prop running at 9600 rpm at 5.3 laps using 80% of battery capacity (2700mah) of a 3400mah battery. All along giving me the feel on how it flies the plane. That feel includes the line tension that I feel comfortable with, turn rate, lack of wind up in the wind, and repeatability. The 13x6 prop will most likely be too big and I'm expecting to cut it down to keep the current draw within my limits. If these don't give me what I'm looking for then I'll try something different. But for now this is the tack I'm taking. I have 2700mah to safely use per flight and I'm trying to convert all of it to airplane performance. Anything less and I feel I'm leaving something on the ground. I'm not trying to get any bragging rights to see how little mah I can use per flight and not have the plane perform the best it can. That's where I'm coming from, to get the plane to perform the best using what's available. Besides, according to all the formula's of watts/pound and such, right now I'm under acheiving those numbers. I'm shooting for about 135 to 140 watts per pound 400-425 watts total. I'm right around 350-360 watts. Leaving 20% of available power that I'm trying to convert to airplane performance on the ground.
My 570 sq in Phacade profile (same size as the Resolve EP electric profile) powered by an OS 40LA uses a 12.5 x 4.5 CF prop. It gives me all of the above with a managable wind up. That's the plane I flew at FCM in Expert last year.
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Maybe we should make a poll to see what prop we want Crist to test!
Right now the APC 12-6 seems to win the most economical for level flight (based on Crist's first flights). I'm guessing that is partly due to the thinness of the APC vs the other two 12" diameter props. Not sure how an APC 11-5.5 would compare, once dialed in to the lap speed.
It is a PITA to adjust the rpm to get the right lap speed, at least a few flights. I just bought one of Will Hubin's new timers, and it looks like the way to set a a series of 2 minute flights for dialing in a run (with ESC in normal governor mode).
One argument for diameter is how it performs for climbing and braking--I think you win there with bigger diameter. Not sure when the P-factor starts to make life miserable for you though--does the pusher help there??. I know for my Nobler that I am at the diameter limit (12") wrt prop clearance, unless I go to 4" wheels!
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Crist,
I was writing my previous post as you were posting.
I think you are going to find a larger prop isn't going to use a lot more energy, simply because you are going to dial it in for your 5.1 s laps (at first at least). The larger diameter will give you more thrust, so you will need to turn down the rpm. My guess is that the larger prop turning slower will be more efficient, and as such, your power draw will drop in level flight. Now I also think that the larger diameter will give you more thrust as the airspeed drops in the climb (which minimizes the loss of airspeed--which is good of course), so here you may pull more power than the smaller prop. So in the end, the total energy needed will the sum of the two effects.
I guess if I were you, and wanted to use the 2700 mAHr from the battery, I would up the diameter and lower the pitch--stay at 4" for example with your 13" prop. This should help lower the prop efficiency in level flight, but increase the vertical thrust in the climb (and braking in the dives). To get to 2700 might really require a low pitch (and high rpm). The high rpm should help burn power. S?P
I think every plane needs a set amount of watts to fly, and to use much more you have to lose it in the prop. Of course if you gain in the verticals, it is a good tradeoff. The question is whether there is a point where the returns aren't worth it. I am sure there is a point, but not sure where it is at. Also I am not sure if we are already nearly there or not.
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OK guys here's the deal. If you had, lets say, a Scorpion 3020-890 890Kv motor and, lets says, a 4S 3400mah battery, and you were going to put it in, lets say, a 50 ounce stunter on, lets say, 60 foot lines eye to eye and want lap times of, lets say, 5.2-5.4 seconds. What kind of a set up would you use and why?
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well with a 890 Kv motor, and a 4s pack, its going to end up being most likely something with a 6" pitch to turn the right rpm,, as to diameter, I dont know the motor,, but I would wonder unless its a small plane drag wise, probably the 12 x 6
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Crist,
I'm coming in late on this and have only skimmed this as I've been pretty busy since I've gotten back home. If I'm off base I apologize. Your setup is very close to the one I am using on my ARF P40. I'm around 50oz and 61' eye to eye with the Scorpion 3020-14 944 kv. Weather I use my 1 3200 mah 4s or my 4s 4000 I am pulling 2200-2400 out of my batteries using a stock 12x6 APC E prop. Laptimes are around 5.1- 5.2 at 9000 RPM. Battery weight is almost the same for the 3200 and the 4000 (about 15 grams lighter for the 3200). These #'s seem pretty consisant with everyone else who is around 50 oz regardless of the plane they are flying. The prop seems to me the biggest constant to me. I dont have any fancy test equipment (just a watt meter and a tach). I'm good at copying what works for others. That prop seems to be very predictable at the Rpm's we tend to fly at. Again,sorry if I missed the point.
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OK guys here's the deal. If you had, lets say, a Scorpion 3020-890 890Kv motor and, lets says, a 4S 3400mah battery, and you were going to put it in, lets say, a 50 ounce stunter on, lets say, 60 foot lines eye to eye and want lap times of, lets say, 5.2-5.4 seconds. What kind of a set up would you use and why?
Hey I know a guy who is having a great time flying a set-up just like that! ;D
Option 1: do nothing but fly it. Trim and improve the airplane to the best of its abilities. Learn how to "camapign" an ECL for a season of CLPA wars. The motor and battery should be under little stress. If the bird flies JUST FLY IT
Option 1A: For 50 oz on 570 squares it might be better to keep the airspeed up AND give the bird a little more room to breathe. If I wanted 5.4 lap times I would also opt for 63' lines.
Option 2: Change parameters and re-optimize. Achieve weight savings by downsizing the motor and battery to just fit the needs of the bird. I think the bird that size does not need any mopre than an 11" prop. That with governor braking should be plenty. Do ONLY if you can achieve a 4 oz weight savings (including potential re-ballasting) which should let you slow down your lap times and keep the 60' lines.
Option 3: new bird to match the capabilities of the power system. Kick the wing area up to 630-650 squares (i'd do it all in wing SPAN ;D) The larger bird will let you exploit the big prop/big power reality of your most excellent power system.
...but that's just me!
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OK guys here's the deal. If you had, lets say, a Scorpion 3020-890 890Kv motor and, lets says, a 4S 3400mah battery, and you were going to put it in, lets say, a 50 ounce stunter on, lets say, 60 foot lines eye to eye and want lap times of, lets say, 5.2-5.4 seconds. What kind of a set up would you use and why?
Is this a trick question? ;D
I would stick on the largest diameter APC E prop that would comfortably fit and lengthen lines to slow it down if necessary.
Why because I think it works as well as anything else (including glow) that I have flown--basically a Brodak P40 is the biggest I have actually flown.
I think you have to satisfy yourself that the run you have flies the plane like you want or expect. What do you think about the way it flies, leaving out efficiency (or lack thereof S?P).
The thing about electric, that I think is really different than glow, is that for any motor/battery combo, there are really many ways to prop the setup that will work almost equivalently. So you can go big diameter, smaller diameter, high pitch, low pitch, ......as long as the governor can hold the rpm constant you will make more power in the climb and have braking in the descent.
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Alan, Everybody,
Not a trick question at all. From my previous posts you all know what 'tack' I'm taking with my setup. I got some interesting feedback and wanted to know what other people would do if they had the same setup as I do. I admit, I don't know all that much about electric CL as most others here on the Forum. I do appreciate the feedback from you guys and it has made me think a little about what I doing. I will continue along the lines of what I stated earlier. In reality, the Xoar 12x6 prop is working very well and I suspect that I won't stray very far from it. I might go to 2 foot longer lines and some minor changes in rpm and such. I do have a lot of power to play with. What I really need to do is what Dennis says, fly the airplane and campaign ECL.
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Crist,
glad the XOAR is working well enough to reference as a baseline for you.
My personal feeling mirrors yours regarding the flatter pitch props. Since you have excess headroom to play with, I would think that running a 12x4 or 13x4 on your setup is still a viable option, assuming you have the voltage at the end of the flight to generate the needed rpm. My new electric will use a Hacker A30 that is 1000 Kv. so it will be more geared towards that specific goal, I also have the 900 Kv A30 that I can swap in place of the other one for back to back comparisons at the field. I regretably have not been able to invest any time in my electric program YET this year. Of course my plan is a slightly larger airframe, more around 630 inches of wing but the same thoughts apply. Please keep us posted, you are generating real time information that we all will benefit from.
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Mark,
The 12 x 5 Xoar prop needed 10,600 rpm to generate a lap time that was usuable. Perhaps it would work if I went with a higher KV motor. Hmmmm...
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Mark,
The 12 x 5 Xoar prop needed 10,600 rpm to generate a lap time that was usuable. Perhaps it would work if I went with a higher KV motor. Hmmmm...
Uhmm - Buy another $75 motor to make a $5 prop work? If it was me, I'd give the prop away and buy more of the ones that do work. y1
Or just go AP^
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The point isnt to make the prop work, its to get a setup that works the way you want. the High rpm low pitch setup is a philosophy about power delivery. Its about the drive and recovery from manuevers, as well as the braking effect coming downhill. My believe is that flatter pitch props get more benefits from the advantage that the govenor gives us in those situations. So its not about making the $5 prop work, its about making the setup work. I have two 120 $ motors for my setup so that I can experiment, but then I also have way more than that in props,, all of which are wood, different brands, sizes, and pitchs. I think its an addiction,,,
Hello, my name is Mark, I am a propellor addict. This week I only bought one dozen propellors,,,
T=One of the cool things about electric is that you do have more flexibility to experiment with this sort of thing. compare a 75 $ motor to a $350 PA 40,, ah well, it works for me anyway,, lol
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Crist, did you fly it with the 12x5 xoar then? did you try any manuevers, I know you probably would not have had enough battery to do much? just curious if you had a sense of any difference in flight
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Yup, Mark is right. It's the package that I'm working on, not just the props. I flew with the Xoar 12x5 prop and I needed 10,600 rpm to fly a 5.4 lap. I only used 1942mah for that flight. I wanted to be around 9600 rpm so I switched to a 12x6 prop. The 12x5 flew very well but I thought the rpm was a little too high for the KV of my motor. I do have some 13x5 Xoar props that I need to try. I'll probably have to cut them down but if they give me a good lap time at around 10K then I might be on to something. Many possibilities for props and rpm's. At least I have a lot of overhead in the battery to try different combos. I'm sure there is a setup out there that will make me happy and get the peformance the plane/ECL setup has to offer.
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Crist,
I would sure be tempted to try the 13x5 stock length if you have the ground clearance, it sounds like you have the current capability in the batteries based on your flight with the 12x5. I would be surprised if you did not see better lap times with the 13 prop at the same rpm since it will be getting a better bite on the air! I may have missed it but what are you targeting for lap times,, somewhere around 5.2 or 5.1 perhaps? thats about where I try to get everything since its more consistant timing wise for my limited experience at the handle. That may just be a dynomite combination. The //xoar props have so little mass, compared to an APC, that it probably wont cause any gyroscopic precession issues either even though it is a 13 inch prop.. Now your getting me excited to get my electric back in the air!
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Mark,
Laps times I'm shooting for are 5.2 to 5.4. Yeah, I'm going to try the stock 13x5 at 10600rpm and see what happens. And yeah my gear is made to deal with a 13 inch prop. y1
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**rubbing hands together with glee*****
I look forward to hearing your results, glad someone else has been thinking along the same lines as me,, I felt like I was on an island sometimes lol,, or maybe that I was off my rocker,, or off my meds,, lol <= n~ LL~
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Did you say you had meds left over? HB~> HB~> HB~> HB~> HB~> HB~> HB~> HB~> HB~>
Hi Gang,
Dean
P.S.
Part of the fun to watch evolution is when folks stop speaking of "the setup" as when copying one of the benchmark setups, and then start speaking of dialing "my" setup to suit me and my airplane.
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Dean, I have meds left over BUT I AINT SHARING!
LL~
Crist,
shouldnt you be out flying,, sheesh, Im waiting here,, lol
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Well I now have 39 flights on the Resolve. I flew it in the Polk City contest this past weekend. The plane flew very well and has a very nice corner. The set up is very strong and I got several compliments on how well it flew. I'm still using the Xoar 12x6 prop launching at either 9600 or 9700 rpm. On average I draw 2450mah per flight. Over the next month or so I'll finr tune the set up including the reverse rotation 12x6 seeing it has less pitch than the standard 12x6. I'm a happy camper! y1
The plane still needs some trimming but I will continue to fly it to build some handle time.
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Great news Crist,
so have you played roulette with props yet, still looking forward to you doing my research for me S?P
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Just keep flying!
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Did some more flying tonight. I tried an APCE 12 x 6 pusher prop. I needed about 400 rpm more than the standard 12 x 6 prop. I really noticed the difference in the outside corners and the Hourglass. Yup, I'm sold. Another benefit that was noticed not only by me but my helper Floyd Layton was that the airplane was better behaved out on the lines. With the standard prop that I was using there were some bobbles, bumps, jerks, etc during the stunts. With the pusher prop the airplane settled down a lot! Now on to getting a 12x6P and repitching down to 5 and getting a 13 x 8P cutting it down some and repitch it ot 5. BTW the standard prop Xoar 12x6 uses 2425mah per flight while the APCE 12x6 pusher prop uses 2250mah for the same lap speed.
Also I used the newest firmware update tonight. Seeing it was calm tonight I didn't notice any difference.
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Did some more flying tonight. I tried an APCE 12 x 6 pusher prop. ..... <snip>.... With the standard prop that I was using there were some bobbles, bumps, jerks, etc during the stunts.......<snip>
So you're saying, a pusher prop gets rid of the jerks? Have to try that. Oh yea, does it get rid of the jerks on both sides of the line? LL~
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So you're saying, a pusher prop gets rid of the jerks? Have to try that. Oh yea, does it get rid of the jerks on both sides of the line? LL~
Very funny Alan!
In a couple of weeks you'll see what I mean.
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Very funny Alan!
In a couple of weeks you'll see what I mean.
Crist,
Yes and you can probably imagine how smug I am that after dallying with poser props, you have come back to the "one true" APC 12-6 prop---even if there are two versions of it!
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Alan, Alan, Alan........
The 1 good prop, a 12 x 6 is an Xoar prop, it just doesn't come in reverse pitch. S?P I ordered an APCE 13 x 6.5 pusher prop to repitch to run at least 9000 rpm for my set up. I'm looking at cutting it down some depending on current draw. I'm working on a pusher prop pitch gauge. I also have another APCE 12 x 6 P that I'll reduce the pitch on so I can run it at the same rpm as the Xoar prop that I'm running. Yes, the APCE props weigh more but I can use a little nose weight.
See you at Mike's?
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Update on props and such. I'm now using an APCE 12.5 x 3.5 Pusher prop. It started out as an 13x6.5P. You can get these at Tower Hobbies. I repitched it to 3.5 on my reverse pitch gauge. I run it at 9200 rpm and draw about 2450mah for a full flight with a lap time of 5.1 sec. I have more on order and will go to a 3 pitch to see if I can get closer to 9600 rpm. Also, I plan on using the full 13 inches. I'll keep you posted as to what I find out. Those of you who are using the 12x6P should try this prop out even if you cut it down to 12. The blade is a little wider than a stock 12 incher. The reason I need to go to 3 on the pitch gauge is because these props are undercambered. Remember, you heard it here first!
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If you go to any lower pitch, you will have to reverse the rotation, and so a pusher will become a tractor and vice versa! VD~
At some point go to 0! LL~
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If you go to any lower pitch, you will have to reverse the rotation, and so a pusher will become a tractor and vice versa! VD~
At some point go to 0! LL~
Then I'll be down to where your anemic current draws are! LL~
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Then you can fly forever!
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on a "serious" note, I cannot believe that zero pitch is optimal --so there must be an optimal pitch.
So what do I mean by that.
Well there is efficiency, and there is thrust vs airspeed. I know that efficiency goes up with pitch (to a limit of course) and my fooling around with prop calculations indicate that lower pitch seems to increase the slope of thrust vs airspeed (a good effect).
Now to optimize, you need to consider the extra weight you carry around to be able to waste watts on level flight, and this will subtract (in some way) from the extra thrust you may get in the climb as the airspeed drops (which is a function of weight).
Braking enters into it too, but again, with our governors, I have a constant lower rpm with higher pitch than you have with a higher rpm and lower pitch. I think you are winning, but I do not really know by how much. Again, total plane weight matters too. At this point, I have not felt my setup is lacking anything---at least compared to previous glow setups.
But that is the great thing--my guess is that the "optimum" is a broad peak with respect to all these variables and there is no big advantage to anyone at this point.
At some point we begin to "argue" about minor details.
My main point is that you don't have to spend a fortune of state of the art equipment to make a setup that favorably compares to a glow setup in cost and weight and far supercedes it in user friendliness. My setup for example is really consistent every flight and offers incredible advantages compared to the typical LA40 Nobler setup. That is what I am trying to get across (outside of this forum!). And the cost isn't outrageous.
Finally (climbing down from my soapbox---actually maybe I am climbing up), I think glow is on its way out. As RC abandons methanol (and the general energy picture), the cost of glow fuel, not to mention its availabilty is just going to skyrocket. And the glow engines will begin to slowly disappear. It will be soon be like 1/2A is right now.
Now you can be sad (I am a bit because I like mechanical things), but still if you like the smell of castor in the morning, enjoy it while you can.
Ok, off the box! H^^
Good thing this is in the electric forum!
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Alan,
The beauty of this hobby is that there are many ways to "skin that cat". On a windy Saturday I plan on trying several set ups. I plan on running the APCE 12x6 running at 8400 rpm (5.2 sec) and then try my 9600 rpm set up. I'll be watching the windup and overheads etc. It would be an interesting experiment. You're satisfied with your set up and I'm close. Different set ups but we still get to fly and have fun. And I agree with with you assessment of costs. I do think that electric is the thing of the future. Glow will be around but electric will be more popular. Much like diesels/sparkies and glow engines today in the USA.
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First a personal perspective, as much as I beleive in electric, I cant see myself doing a classic ship with electric just yet anyway, around here that would likely get you tarred and feathered! lol,,
now, as for your comments Alan about "wasting " energy with a high pitch setup. I dont get where that comes from, perhaps if you use your same motor and wind it up you might, but if you get a different motor with a higher KV and run a high rpm low pitch setup, it will be just the same efficiency as the low rpm high pitch? to put it in another light. If you use the same diameter prop, but with a flatter pitch, it will move the same column of air ( spaure inches of prop area) with more thrust, even at flight speeds. but it will take the same power to spin the flat pitch prop at a higher rpm because there is less drag per revolution of the blades, IOW they are taking a smaller bite of the air each time they rotate so it takes less watts to rotate it per rpm. This is my take on it,, FWIW. I also believe that a high rpm setup all else being equal, will generate a much better airspeed to rpm ratio, and breaking affectivness than a high pitch setup will. My target is somewhere around Crist, though a bit higher, I want to spin about 10000 to 10500 rpm with a 4 pitch prop or thats where my "calculations" put me. that will be with a Hacker A30-8XL that is capable of over 650 watts, though I dont plan on using all of it. regretably, it will likely be this fall before my new testbed takes the air. I have to finish the Avenger, and the 109 profile, (Crist this is the one you cut cores for quite a while back) and Jessica wants to finish her plane too,, sigh,,
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Mark,
I "think" that a two props of equal diameter but different pitches making the same thrust at flight speeds will give the nod in efficiency to the higher pitched prop. How much different I don't really know of the top of my head. The reason I think is that things like drag etc. are not simply linear in velocity, so a faster spinning prop should take more power than a lower rpm prop--to make the same thrust. There of course should be a limit to how much pitch works, but I am guessing that other concerns begin to matter first--like how thrust increases as the airspeed drops--here I think flatter pitch wins, but again it isn't a night or day thing.
My main comments is that flat pitch props were a concession to the modern glow engine power/torque curves. The electric motor is completely different in that regard, so it just isn't obvious that flatter and flatter props are really bringing something to the table.
But I could be wrong!
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I got some more 13x6.5P today. I repitched one to 3 at station 10. It is the full 13 inches in diameter. We'll see what happens this weekend.
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Went out and test flew some props in the 15 mph wind last night. The only change I made between props was the rpm setting on the ESC to try and get a 5.1 to 5.2 lap speed. All props are APC pusher props. Here are my results:
12 x 6P (5.25 on my pitch gauge) stock prop - 8800 rpm 5.15 lap time - excellent line tension - quite a lot of wind up
12.5 x 3.5P (13 x 6.5P cut down and repitched) - 9300 rpm - 5.15 lap time - very good line tension - less wind up than 12 x 6P
13 x 3P (13 x 6.5 repitched) - 9600 rpm - 5.25 lap time - good to very good line tension - even less wind up that the 12.5 x 3.5P
My conclusion is that the higher pitched props allow more wind up and give better line tension in the wind on my set up. As the saying goes - "You're mileage my vary."
I have decided to go with a cut down and repitched 13 x 6.5P APCE props to 12.5 x 3.25P. This will give me a little head room before I get to 80% (2700mah) of my battery capacity of 3400mah.
Sure wish APC would come out with a 13 x 4P prop.
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Crist
ANOTHER great set of data. Geez what a difference a year makes. You gone a LONG way from the Barnstormer with the 13x8(?) or what ever it was you were flying last summer!
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Thanks Dennis. No more datalogging and such. On to putting cycles on the batteries. BTW I'm on cycle 17 on each battery.
http://www.rcgroups.com/forums/showthread.php?t=1058812
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Crist,
thanks for sharing, great information!
good luck flying now, have a great season
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Crist, what does the term "wind up" mean. Is that RPM gain on the downwind run?
Great info, thanks,
John Witt
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"Wind up" or "whip up" is when the airplane gains speed when doing stunts on the down wind side of the circle. Most noticable when doing the 3 inside circles. It's like having a kite doing loops that get faster and faster and eventually you will run out of elevater and can cause crashes when it is at its most.
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Crist, what does the term "wind up" mean. Is that RPM gain on the downwind run?
Great info, thanks,
John Witt
John,
If you are using a governor the rpm won't increase (or decrease), so what is going on is that the motor--through the prop -- is resisting the speed up of the plane by the wind (always have an issue is it wind-up (like a wind up toy) or is it wind-up (pronounced like the wind that is causing the whole issue)).
A good feeling for how good the braking is (no, not breaking!) is to turn off any braking function on the ESC---so when the timer quits, the prop windmills--boy do you come down fast compared to actually stopping the prop with the break brake function (sometimes I do stop the prop with a break!).
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OK, I get it. I assume one of the PA goals is to fly a constant ground speed around the circle, regardless of the wind. So you have two cross-wind portions, one headwind, one tailwind, and the transitions between. The governor will then be trying to keep the air flow through the prop constant as it loads and unloads in the transitions. Would I be right in thinking the transitions are the important parts where the governor is working hardest to keep the RPM stable?
I have the gain in my CC PHX 45 set to medium. Does the RPM stability benefit from setting the gain to high ( not too high!). I would think high is where to run it as long as the speed doesn't hunt. CC doesn't say much about the control algorithm or give one much in the way of options to modify it. Since it is a consumer product, there won't be many people using it that have the understanding necessary to fine tune the control anyway.
Good stuff, guys.
John
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John,
If you look around here (probably my thread on my Nobler from last year), I posted a graph from my data logger of what my power system is doing.
Even in level flight, you can see that the motor "sees" the wind. I was initially surprised to see that it is working hardest when the plane is flying with the wind, and is having the easiest time flying into the wind. The power/amp trace looks line a sinusoid.
So what is going on is that the airplane, with a fixed rpm, wants to keep a constant airspeed, not groundspeed. So when the plane comes around from the upwind part of the circle, it has to accelerate to catch up to the wind to keep the airspeed constant (increasing groundspeed of course), and vice-versa as it comes around from the downwind part of the circle.
Every plane (glow or electric) does this. The difference is how the motor/glow engine handles the changing load. With a governor, our motors keep a pretty constant rpm. Glow engines have their own characteristics, depending on how they are set up, 4-2-4, high rpm/low pitch, piped, 4 stroke. I think the piped and high rpm/low pitch setups (maybe 4 stroke too) are closest to our governor setup because the engines are typically running near max rpm.
Anyway, getting back to your question, you want the gain of the governor setup high enough so it can respond fast enough to quick changing loads---basically a square corner is probably or fastest change, and that is on the timescale of a tenth of a second or so. If you set the gain too high, you will hear the motor "oscillate" in rpm when the load changes. It is pretty audible. At that point cut back on the gain. You can start with a moderate gain and go up until you hear the "warble"--I heard it at the top of my loops. Then back off a point or two in the gain setting.
I basically just set a moderate gain and don't notice any rpm fluctuations from my datarecorder that I can associate with the load changes. I basically think that we are not stressing the load factor in our application--like an RC Helicopter does in some of its 3D maneuvers.
Hope this helps.
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Alan, I was using airflow through the prop as a euphemism for airspeed, but I see your point. No way to keep a constant groundspeed without some kind of reference.
So do you have any info about what the CC software means relative to response times for the governor gain, for instance is low to med to high an order of magnitude each time, or a doubling, or some nonlinear factor?
I'm scheduled to fly Saturday AM, so I think I'll take my laptop and try changing the gain and see how it works.
Interesting that a lot of E-flyers are interested in numbers and numeric modeling. I think that might be because we can get the info. A glow engine is hard to compute.
John
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John,
No I am not privy to the inner workings of the CC ESC governor. They are pretty vague about what exactly the input numbers really mean.
It is an advantage to have the data recorder since if it looks good on the recorder--then it's good enough. Like I said, I think my gain is set somewhere in the middle range. Since it worked right off the bat, I didn't fool around with it. Now if I saw my rpm's sag, then I would up the gain.
The only time I had the governor over-gained was a couple of years ago with my Electric Super Clown setup, running at that time with the Stock Brodak motor (kV=1500 rpm/volt). That motor had 10 magnets in it and so I had to run the CC ESC in (I think) high governor mode. These are the good old days, believe me, compared to back then. I don't recall why my gain was too high, but you should have seen me jump when the ESC overcompensated at the top of the loop.
Now we have a new firmware (actually I'm talking about last summer's update), and for me it works really well--I use "Set RPM" mode.
I am sure some of the other guys who like to play with the settings will chime in and tell you where their gains are set.
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IIRC my gain is set fairly high. cant say for sure just how high, but its in the upper range of the available settings. have not looked at it for awhile though.
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With Gain set to mid setting, we noticed some "wandering" of RPM in level flight. A talk with Castle suggested that a lower gain setting (down to 3 using "Custom" option) would smooth things out - and it does.
Unfortunately, my still limited testing SEEMS to suggest that the lower gain shows up as less governing ability in manuvers - I guess that seems logical, and seems to dovetail as the opposite example versus Alan's experience with Gain set too high.
Has anyone else experienced this?
Anyhow, I think I will re-set the gain to either LOW or MODERATE and let it ride for now. I have more work to do setting my flight speed, then will look at changing Gain setings
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I should note that I base my "gain" observations primarily on my data recorder rpm measurements. So I say that I am satisfied because I don't see any apparent sags or surges of the rpm level during a pattern flight.
If I didn't have this data, I guess I would play more with the gain setting since the main feedback (as far as I know) is when you overdue the gain setting and can hear the overshooting and undershooting (prop noise) during the maneuvering---like I heard with my Super CLown when I apparently overdid the setting.
Of course it is painful to make these ESC changes if the PC is back home, and not at the field. But as they say, no pain, no gain! H^^
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I guess I need to go back and look more carefully at the software (using ver 3.13) and the help explanations. I realize I don't understand the difference fully between the "set RPM" mode and governor mode. There's the effect of the timer settings on the system as well. I'm using the Z-Tron and running at 90/95% throttle. I'm wondering if that just sets a ceiling on the available output that the ESC can use to regulate prop speed, since the timer I assume is regulating the PWM pulse width which in turn limits the ESC current throughput. The voltage is whatever it is so you have a ceiling on the available torque.
Does the set RPM mode act as a throttle (trying to run at a set RPM) in the ESC, with compensation for load; whereas the governor mode would run at the motor at the output set by the timer at whatever RPM resulted from that throttle setting? I guess what I'm saying is: you can have a set RPM or a set torque (gov mode), with an internal feedback loop for each mode which has an adjustable gain.
Does that match your understanding of how it works, or am I off in left field a-gain.
John
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John,
You sound as confused as I was when I was trying to figure out how i was suppose to setup the governor. It took some time and patience from the guys here on the forum to talk me though it (a belated thanks!).
Anyway here is the way to look at it. First lets look at normal governor mode:
In "normal" mode, the ESC is looking at the pulse coming out of the timer/throttle (the Ztron in your case). The timer puts out a 1-2ms pulse at a 50Hz rate. A 1ms pulse is interpreted as throttle "off", and a 2ms pulse is throttle "full on" =wide open throttle or WOT. So lets say you set your Ztron dip switch for a "25" setting---which I think is right in the middle of the throttle range. Then the Ztron would put out a 1.5ms pulse. This is nominally equivalent to the throttle channel output on a RC receiver.
ok, so far, so good. Now the trick is how the ESC interprets this signal. What it does is map the Ztron output into a rpm range. Now you should know, the ESC doesn't really measure rpm directly, but it is counting the signal that the permanent magnets make as they spin around the stator. A typical motor that we are using has 14 magnets. I think Dean Pappas once gave us the conversion between the Ztron pulse output and the rpm level. Anyway the Ztron output maps onto a rpm and it is a little trial and error to figure it out. When I use to use this mode, I would replace the normal propeller with a small 2"diameter disc that had alternating dark and light quadrants. My tach could read the rpm of the motor this way, without worrying about a dangerous 9000 rpm prop whurling around. By playing with the timer, I could map out the rpm as a function of the timer setting. A little tedious, but it worked.
If you are still with me, once the throttle setting is made, the governor will try and keep that rpm setting, as long as the throttle setting stays the same. So if the load goes up (like in a climb) the ESC governor will increase power to the motor, and take it away as the load goes down. As a result the rpm stays constant. The only limitation is that the rpm itself must be attainable by your particular motor and battery. That typically means that we fly our level laps at ~75% throttle. If the power needs go up, the ESC can draw on that remaining 25% to increase the throttle. Now it isn't completely clear what 75% actually means to everyone--to me it means that the ESC is outputting a PWM pulse that is on 75% or the time and off 25%. That actually translates into less than 75 % power (I think).
There is a small wrinkle called "high" and "low" governor mode--and that is because you may want a higher target rpm range than what is considered "normal" (normal was defined for helicopter pilots).
The advantage of the above type of governor mode is that if one day you think you need a little bit more "oompf", then simply increase the Ztrin throttle setting a click or two higher, and the rpm will increase some too. Last I recall each click is in the 100 rpm range--but I forget because...
I use the set rpm mode. I was tired of the back and forth setting stuff, and knew where I wanted to fly. In Set RPM mode you can set 3 target rpms. The first value is for timer throttle settings above 0 and less than 50%, the second above 50% and below 99%, and the 3rd is for 100% throttle. I set the first value to be 7500 rpm, the second to be 7950 rpm, and the third also to be 7950 rpm. I then use my timer so that when I take off, the throttle value is ~45%. This gives me 7500 rpm for a nice calm takeoff. I then set the timer to ramp the throttle from the 45% value up to 100%. Now this took a few trials and errors, but right now, my timer passes the 50% point about 1.5 laps before the wingover--so when the ESC sees the 50% value, it ramps the rpm to 7950, and holds it there the rest of the flight.
But the disadvantage, at least the way I am using it with the reduced takeoff power, is that I am locked into a flying rpm, and can't change it unless I bring a laptop to the field. If I didn't care about the takeoff power, I could set a windy weather rpm and a calm day rpm, and then just adjust the timer to one of the desired rpms. Or if I had 3 timers already setup, I could just change timers.
Well this was another long winded post. I hope it isn't confusing you.
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OK, yes, that makes sense. You state it very well. So now what we need is a pot on the ESC to set the RPM, instead of software. So the glow guys have a can of fuel, a starter and its battery and a glow plug lighter and we have a cable and a laptop. I think that blows the cost comparison, but of course we can play Solitaire on the laptop while the batteries charge. n~
Well, if I have enough time Saturday I will try a couple of things. I only have two batteries and there is a 50 min charge time currently, so that gives me some time to set the software up. My flying doesn't offer real consistent behavior, so sometimes it's hard to evaluate what's going on. That is getting better gradually, at least now the Panther is flying well enough to change one thing at a time. BTW does anyone make a three blade prop that's roughly equivalent to the APC 12-6. The 12 inch prop runs me out of ground clearance and I broke the tip off the only one I had. I have a Master AS 11-7 3-blade, but it doesn't seem to pull out of hard turns as well as the 12-6 2-blade.
The plane actually is running pretty well as set up right now, but you know we cannot resist "trimming".
John
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Yes I keep hoping that APC will come out with a 3 blade version of the 11 and 12 inch props. For right now you could join the "Stork" club ----lengthen the gear and/or use larger diameter wheels.
I do both, but to be honest, takeoff from grass fields is somewhat problematical. Too many times (at least 3 times now I think) I have ripped the motor assembly out on takeoff when the prop sticks into a clump of grass. My reaction is to perform a "soft field takeoff", which does get me off the ground ok, but basically kills any takeoff points. I probably should trim the tips of my 12-6 down a hair or two.
Now maybe we should let Crist have is thread back!
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Roger that, Crist is being very patient--Thanks to all you guys for not making me re-invent the wheel.
John
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Roger that, Crist is being very patient--Thanks to all you guys for not making me re-invent the wheel.
John
Of course not. Alan wants you to re-invent the landing gear leg..! ;D n~ LL~
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I was going to say sumpin'! n1
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I was going to say sumpin'! n1
Hey at least we keep your thread up at the top and make it look important! y1
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I appreciate it that. BTW, it is important! y1
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up to 4 pages - has to be one of the largst/longest running threads in th E-forum, LOTS of good data posted in it too. Thanks to all
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Well, took a little time to check bench trim and add some permanent nose weight this morning. I added about 3/4 ounce of nose weight weight. It is now up to 51.7 ounces and 12.8 oz per sq foot. I checked the vertical CG and it was very close. I then checked the balance and marked it on the wing tip. BTW it balances about 23 to 24% MAC. I then ran the LO position on Line III (thanks Bob) and got a position of .766 inches aft of the CG. I was running the LO about 1 inch aft! I moved them forward to the .766 inch mark. Now to go fly it this afternoon. I'll let everybody know what the outcome was.
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The LO were pretty much right on target. #^ Aproaching 80 flights on the bird! Feeling comfortable with the plane. Did I mention how much I like the pusher prop? y1
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Sounds really good Crist. Lessee:
* moved the CG forward a little (3/4 oz)
* THEN(?) checked CG against Line 3 and decided to move them about 1/4"
Sounds like smidgen of this offset by a skootch of that... Sounds like you got it nailed!
Sorry I lost track, WHICH pusher are you using now? How many mah?
Any luck on the LH crank for the LA yet?
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Dennis,
You make sound so unorganized! n~ The bottom line is it seems pretty close to be dialed in. Adjusted the neutral setting on the handle yesterday too. Going flying this afternoon after church so I'll put some more time on the Resolve EP.
The prop is an APCE 13x6.5P cut down to 12.5 and repitched to 3.25 at station 10 on the Prather gauge. I slowed it up by 200 rpm yesterday to 9200 with a lap time of 5.2. 9400 rpm gives me lap times of 5.1 Very good to excellent line tension everywhere. About 2200mah at 9200 5.2, and 2450 at 9400rpm 5.1 laps.
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At the SIG contest it was very windy both days. On Saturday, I flew my standard set up and sailed a bit in the vertical eights. I managed to post a 445.5. The laps time was about 5.1 I used 2008mah. Sunday was even windier. I boosted the rpm by 500 and flew 4.8 laps to deal with the wind. No problem. I kept up with the speed and the plane flew though the turbulence and wind very well. I posted a 471.5. I used 2558mah. It didn't have to go that fast so next time I'll only try a boost of 300-400 rpm.
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Crist is correct. I was watching the flights on Saturday and could see the difference between the IC planes and Crist's electric. Only a few of the IC planes came close to mainting a constance speed, but his electric was great at keeping a constance speed. Crist was able to put up a very good flight.
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Thank you John, I appreciate the kind words. I have over a hundred flights on the Resolve EP now and it just gets better and better. I had a very good day today getting ready for the Nats. I added about 1/8 ounce tip weight and increased my line spacing about 1/4 inch. I really do like the pusher prop set up.
BTW, I checked the pitch on my props and I'm now running a 12.5 x 4P prop measured at station 10 on the Prather pitch gage.
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I'm back from the NATS and the Resolve EP performed very well. It garnered 13 appearance points. The only change I did to it all week was to add 100 rpm after Sunday's early morning practice on the L-pad. I only wish that I flew better. I answered a lot of questions about electric stunt this week. Paul Walker flew it and said that it was good. A little nose heavy for his taste. He put up close to a 500 pointer on the one and only flight he flew! Archie Adamisin flew it and he liked it too. Plenty of power. I'm going to work the CG aft and possibility of increasing the line spacing some too.
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Congratulations on your finish Crist. You didn't bring back any Tatoos did ya ??? ??? LL~ LL~ LL~
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Crist,
Thanks for the oppurtunity to fly the Resolve 570. It certainly answered a lot of questions I had about the effect of the pusher prop. Your power-system is very stout and you know it well. I liked how well it packaged and it certainly pulled hard. The Resolve 570 is a great flying bird. I wish I had the chance to watch you fly it.
This a great thread for anyone who wants to know how to set-up a successful ECL system. Not to mention that Crist is a first class guy!!
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Lee,
No tatoo's this time!
Archie,
Thanks for the kind words. You flew my airplane better than I do. Yup, the pusher prop thing works very well.
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Crist,
You saw my second pattern of the year. The first was with the Uncle Dennis' Hellcat. Maybe I need to build something? LL~ LL~
Archie Adamisin
Muncie, Indiana
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Latest update.
I flew the Resolve today and it was fast. Yup, I had to take out the 100 RPM I put in at the Nats. I also removed some nose weight and shifted the battery aft. Much better feel to the plane. I then went to 2 foot longer lines (62 ft eye-to-eye) and the plane felt a lot more to my liking. The extra 2 feet gave me just enough more time and the plane was flying very good. The air was pretty dead and while backing up on the outside loops I hit my wake. It pancaked in and bounced up and I continued inverted for about 1/4 lap. Took off the rudder/fin and the prop. Scuffed up the top of the canopy. The damage was pretty minor. I was contemplating modifying the fin anyway. It'll be flying in a couple of days.
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Ahhhh, it has finally been "Cristened"! LL~
It now joins the fleet of "Ground Rounds"!
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Ahhhh, it has finally been "Cristened"! LL~
It now joins the fleet of "Ground Rounds"!
Alan,
LOL! I forgot about that "trend" of mine.
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Yep and the canopy has been "Tatooed" LL~ LL~ LL~ Da Plane Da Plane.
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Final note for the airplane. The 4 battery packs gave me a little over 60 cycles each over the 2 years I have had the plane. The batteries are now getting "soft" and are starting to puff slightly. They have been retired. I paid about $65 for each battery delivered to the door and they have pretty much matched the cost of glow fuel. I was hoping for more cycles but didn't get them. Now for the search for a good replacement battery. The good news is that batteries have come down in price over the last 2 years. BTW, the plane still looks brand new and flys very well. Wait till you see what I'm building for next year!
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I am building an E-Primary Force. Would it be possible for you to post some pictures of the nose and how everything was mounted. I am trying to design something, but a proven design would definately help.
Thank You
Michael Duffy
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Look in pages 1, 2, 3, of this thread. I posted plenty of pictures of the front end.
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Scorpion SII 3020-890 and my 4S 3400mah battery, CC-45 ESC and a JMP-2 timer and prop TBD! :##
I will be needing some 4S 3400mha battries for my La-5 profile scale project. In an earlier photo the battries look "no-name". Can you tell me a little more about them? $, source etc.
~> #^ ;D
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I will be needing some 4S 3400mha battries for my La-5 profile scale project. In an earlier photo the battries look "no-name". Can you tell me a little more about them? $, source etc.
~> #^ ;D
I had them made up for me from PolyNoOne. They made them for me and they came out to 313 grams. 11 ounces.
Here is a forum link to the discussion;
http://www.rcgroups.com/forums/showthread.php?t=908662&highlight=pno
I'm not sure they are in business any more.
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Final note for the airplane. The 4 battery packs gave me a little over 60 cycles each over the 2 years I have had the plane. The batteries are now getting "soft" and are starting to puff slightly. They have been retired. I paid about $65 for each battery delivered to the door and they have pretty much matched the cost of glow fuel. I was hoping for more cycles but didn't get them. Now for the search for a good replacement battery. The good news is that batteries have come down in price over the last 2 years. BTW, the plane still looks brand new and flys very well. Wait till you see what I'm building for next year!
I fitted the plane with my Thunder Power G6 V4 5S 2700mah Pro Lite batteries and a 650kv motor. While the kv is a little low, should be around 710 or so, the airplane has a new lease on life. As a matter of fact, I'm going to use the plane for practice to rid myself of some undesriable hand movements/placement while flying the schedule.
I also found out at this year's NATS that running the governor gain all the way up works really well. I'll make that change too.
It is still a very good flying plane!
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Update on the Resolve. I've been flying this plane in Profile at this year's contests. It has been fitted with a Cobra 2826-760Kv motor. I replaced the shaft so I have some shaft extending out of the back of the motor for the rear support bearing. I'm still using the TP G6 5S 2700mah batteries. I'm using about 1850mah to 2000mah depending on wind and lap speed. I like the 62 foot lines too. Still my "go to" plane. Stiill looks very new.
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What prop are you turning on the Cobra 2826 ? :)!
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What prop are you turning on the Cobra 2826 ? :)!
A APC 13-4.5EP cut down to 12". Thick hub version.
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HI Crist,
Sounds like you have really gotten a lot of things sorted out with this model. It is great to have a model that flies extremely well and you can concentrate on other things like flying the maneuvers!
Another good looking one is your tricycle LG that you are now building. It should be a good one!
BIG Bear
RNMM/AMM
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HI Crist,
Sounds like you have really gotten a lot of things sorted out with this model. It is great to have a model that flies extremely well and you can concentrate on other things like flying the maneuvers!
Another good looking one is your tricycle LG that you are now building. It should be a good one!
BIG Bear
RNMM/AMM
Thanks Bill. Yeah, 2009 570 profile AKA Resolve EP is my goto plane.
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Just a short update on this plane.
A few weeks ago I decided to extend the nose and remount the motor. I had some lead weight buried in the nose and wanted a more forward CG than before. Also I switched from the Cobra 2826 to the Cobra 3515/18 740Kv motor. This is the same motor I'm using in my 2016 Agneda plane.
As a matter of fact. it uses the exact same set up as the Agenda.
I was out this morning at Hobby Park. What a nice morning. About 75 to 80 degrees and a 4 mph breeze from the south. I put in 6 good flights!
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Was the sun up yet? LL~ LL~ Sounds like you are getting the plane working. My self haven't been able to go fly because granddaughter need the car for work. Also temps in the high 90's and higher with gusty winds.