stunthanger.com
Electric Stunt => Gettin all AMP'ed up! => Topic started by: Crist Rigotti on November 13, 2010, 09:16:24 PM
-
OK guys. A build thread on next year's stunter. It will be similar to my Resolve from 2 years ago. Some basic stats:
Wingspan - 56 1/2 inches
Wing area - 620 sq in
Tail Volume - 25%
Motor - Scorpion SII-3026-710
ESC - Castle ICE 50 Lite
Battery - Flightmax 5S 3000mah 20C Thunder Power G6 5S 2700mah Pro Lite
Timer - JMP....for now. Might go with Wills timer and control box. Using Wills programmer box and FM-9 timer.
Prop - 13 x 4.5EP
Foam wing
Monokote finish
Trike gear
Profile design
Wing mounted gear
Be sure to click on the pictures of the drawings after they are opened to see a much clearer picture.
edited on 4-30-2011
-
I'll let the pictures do the talking:
-
The stab. I used some .007 CF on the LE and TE. The LE, TE, and tips are laminated from 3/16 sheet with 1/32 sheet in between. The 1/32 sheet is skipped where the hinges go thus creating a hinge slot. Very neat and dead center of your surface. The holes in the ribs are so the air can escape when covering the stab with Monokote.
-
Wow that looks GREAT. Looks like the logical progression from the "Resolve". Nice profile view, I like the trike layout too.
-
Looking great Crist. Can't wait to see more. Your power system sounds perfect! :)
-
The stab. I used some .007 CF on the LE and TE. The LE, TE, and tips are laminated from 3/16 sheet with 1/32 sheet in between. The 1/32 sheet is skipped where the hinges go thus creating a hinge slot. Very neat and dead center of your surface. The holes in the ribs are so the air can escape when covering the stab with Monokote.
That's the same way I like to build hinge pocket components. Perfect slots every time..
Last night I read the better part of the thread on the 1st Resolve (all 4 pages). And I was thinking he should have made it a little bigger, because you could still build it in the low 50's weight range with more wing area (I recently built a RingMasterDeluxe with 620 area came in around 49oz on .36 glow power). And now I see this today, and I'm thinking this might be the one that makes me take the big jump into electric c/l. So Crist, are you selling plans and/or foam wings yet ?
-
That's the same way I like to build hinge pocket components. Perfect slots every time..
Last night I read the better part of the thread on the 1st Resolve (all 4 pages). And I was thinking he should have made it a little bigger, because you could still build it in the low 50's weight range with more wing area (I recently built a RingMasterDeluxe with 620 area came in around 49oz on .36 glow power). And now I see this today, and I'm thinking this might be the one that makes me take the big jump into electric c/l. So Crist, are you selling plans and/or foam wings yet ?
LOL! Not quite yet. I'm hoping that it will work out well. I'm a bit on the smaller size so a "tweener" works best for me.
-
More wing photos. Notice I laminated the wing TE using 3/16 balsa and 1/32 to form the hinge slots. I'm molding the LE skins over the next several days. I put 2 ink lines on the TE to guide me when I plane it down. Also I'm almost finished with the fuselage details on my CAD program. I'll post a picture of it when it's done.
-
Looking great Crist. Your attention to detail is inspiring.
-
The side view with details.
-
Ooh -- pretty. I like the side view, and I'm impressed by your woodworking.
Why trike gear?
-
I have a Pathfinder ARF that has trike gear and I was impressed with how easy takeoffs and landings were. Or should I say how smooth the take offs were (read higher score) and how easy is was to make a no bounce landing ( read higher score)!
-
I prefer the 1st one with the canopy back at the LE.
Also the rudder shape looks better on the 1st one..
What's the nose and tail moments on this one ?
-
Queston about desiging a trike gear layout.
What incidence are you shooting for when sitting on the gear.
Neutral, slight positive or negative ?
-
Queston about desiging a trike gear layout.
What incidence are you shooting for when sitting on the gear.
Neutral, slight positive or negative ?
Neutral or slightly negative I've heard.
-
Lookin real good there Crist. Is the spar and landing gear set up on this the way you described how to do the P-63 foam wing you cut for me ?? I wonder what color scheme you've picked out LL~ LL~ LL~ LL~
-
Lookin real good there Crist. Is the spar and landing gear set up on this the way you described how to do the P-63 foam wing you cut for me ?? I wonder what color scheme you've picked out LL~ LL~ LL~ LL~
Yes, but my LG blocks are on the front of the spar. Your P-63 the LG blocks should be on the aft side of the spar. Probably I'll change the color scheme on this one from red, white, and blue to blue, red, and white. y1
-
Thanks Crist, also I'm glad to hear your getting out of that same color scheme rut. n~ n~
-
Thanks Crist, also I'm glad to hear your getting out of that same color scheme rut. n~ n~
Naw, Crist isn't in a "rut" he is "in the groove"! 8)
-
Naw, Crist isn't in a "rut" he is "in the groove"! 8)
LOL!
-
Crist,
I'll have some clear two-part left for you to use as the final coat. LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~
-
Crist,
I'll have some clear two-part left for you to use as the final coat. LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~ LL~
For my handle..right? #^
-
Crist, Since your "In The Groove" VD~ Don't forget to paint your handle as you paint your plane. I know you like that, then use the 2 part clear. y1 y1 y1
-
OK, it's been awhile since the last build post. Here are the wings. They are sheeted, and the weight box with screw and cover installed. The tips are installed and all that has to be done to them is some final sanding, add the bellcrank with LO and pushrod and then join them. Cutting the holes in the foam is not for lightness but to allow the air to move around when I'm covering them with Monokote. BTW cutting the holes saved a total of 8 grams for the entire wing. The wings weigh 9 ounces as they sit.
-
Looks good there Crist. What was your tool of choice to cut the holes ??? See ya Saturday at Thunder Bay.
-
On wing honeycombing:
I've understood that R/C Pattern guys who honeycomb their fully sheeted wings mainly do it to save on the glue weight.
picture stolen from:
http://www.rcuniverse.com/forum/m_256678/mpage_1/key_/tm.htm
(http://images.rcuniverse.com/forum/upfiles/33241/24402_12174.jpg)
-
On wing honeycombing:
I've understood that R/C Pattern guys who honeycomb their fully sheeted wings mainly do it to save on the glue weight.
picture stolen from:
http://www.rcuniverse.com/forum/m_256678/mpage_1/key_/tm.htm
(http://images.rcuniverse.com/forum/upfiles/33241/24402_12174.jpg)
Kinda hard to get the leadouts through that wing! Also if you noticed that I didn't fully sheet the wing.
-
Sorry, I am not suggesting you should have do it like that. Just mentioning that on a slightly related note...
-
Sorry, I am not suggesting you should have do it like that. Just mentioning that on a slightly related note...
OK.
-
Looking great Crist!
-
I have the bellcrank and flap pushrod made and installed. Leadouts terminated, and the wing panels joined. Just some little sanding, then I'll add the 3 circles of silkspan on the top and bottom for reinforcement. Then she'll be ready to cover.
-
Make your own B/C ???
-
Make your own B/C ???
Oh yeah, you can't buy that quality!
-
Oh yeah, you can't buy that quality!
Only in an old time furniture shop, right Larry LL~ LL~ LL~
-
Only in an old time furniture shop, right Larry LL~ LL~ LL~
LOL! LL~ LL~ LL~
-
Our bearded crew makes only the finest picnic tables and house heaters. 'Nice plane, Crist....I like the jet styling!
-
Looks good there Crist. What was your tool of choice to cut the holes ??? See ya Saturday at Thunder Bay.
1/16 ply template with a 1 1/2 inch circle and a soldering iron.
-
Here are the flaps. Made using 2 pieces of 1/8 7.5# balsa and 1 piece of 1/32 6# balsa. The 1/32 balsa is sandwiched between the 2 1/8 balsa to form the hinge slot. I notch the 1/32 where the hinges go. I use slow setting epoxy to do the laminating.
The horn clips are made from 1/8 lite-ply and aluminum tubing so that the flaps are removable. Same thing for the elevators. The flap tips along with the roots are lined with 1/16 basswood to give me a good "edge" and to strengthen both the tips and the roots.
I have them shaped but still need to round the LE and TE.
-
Here is what I do to reinforce the center joint of my foam wings. I got this method from Allen Brickhaus. I use 3 circles of medium silkspan of 4, 6, and 9 inches in diameter. The 4 and 6 inch circles are centered over the bellcrank post. The 9 inch circle is positioned so that the front (LE) edge is about even with the 6 inch circle. Use 3 circles on both the top and the bottom of the wing.
I brush on 2 coats of unthinned nitrate on the bare wood. I lightly sand the wood and then apply the 4 inch circle wet and brush on with nitrate. Once dry, I brush on another coat nitrate dope. Then I sand the circle and repeat for the 6 inch circle. Do it again for the 9 inch circle. I then use 50/50 thinned nitrate for the last coat. Then I sand lightly. BTW, Monokote sticks extremely well to the doped silkspan.
Here are a few pictures and I hope they show the silkspan.
-
No f/g tape on the center joint???
-
No, none. It isn't needed.
-
The elevators are built. The same construction as the flaps. I've included a picture of the horn clip and aluminum tubing that I use to make the elevators removable.
-
Flap and elevator construction ?
Do you taper them or just round the edges ?
-
Flap and elevator construction ?
Do you taper them or just round the edges ?
I've done both, but usually just round the edges.
-
Crist,
Looks like a great plane and a possible article in some magazine.
Merry Christmas and a Wonderful New Year.
Allen Brickhaus
-
Well I shortened the nose some.
-
Glad to see you are back to work on it!
-
Rudder and vertical fin are built. All the pieces except the fuselage are now built. The wing needs some final sanding and the stab, flaps, elevators, fin, and rudder all need to be sanded and the edges rounded. Then I'll start to Monokote those pieces. After all that is done, then I'll start the fuselage. I finish all the other pieces first, then do a weight and balance to figure out how long the nose has to be so the airplane will balance where I want it to.
-
OK. The wing, stab, flaps, and elevators are covered and the trim stripes have been added. The elevators and flaps have been hinged. Pictures tomorrow.
Started the fuselage tonight. I have the basswood engine bearers glued in and 1 side has the 1/64 ply glueing as I type.
-
I also decided to go with a shorter nose and using a 6 cell battery. I'll have to use a 600KV motor to get the RPM range where it needs to be.
-
THe short nose looks great too. Howzit looking for weight?
-
It'll be 58 to 59 oz. I was shooting for 56 oz.
-
Boy Christ a guy can larn a lot or not by coming to this portion of the forum. After talking to Bobby Hunt at VSC I am almost convinced to go to ECL. But, I have so many IC engines. By the way did I say this is a fantastic build you are doing. I like the pictoral presentation. That is what I am slowly doing with my project right now. Maybe see ya down the road if I can get this knee problem whipped. H^^
-
The fuselage framework is all done. I'm glueing on the sheet balsa sides as I type.
-
Boy Christ a guy can larn a lot or not by coming to this portion of the forum. After talking to Bobby Hunt at VSC I am almost convinced to go to ECL. But, I have so many IC engines. By the way did I say this is a fantastic build you are doing. I like the pictoral presentation. That is what I am slowly doing with my project right now. Maybe see ya down the road if I can get this knee problem whipped. H^^
Thank you Doc.
-
Ok, the fuselage is done except for final touch up sanding. 1/2 ounce under budget!
-
As we've come to expect it looks great Crist. When do you project the first flights to be ???
-
I covered the fuselage today. It still needs trim stripes and some "ink" lines. Here's a sneak peek.
-
Looking good Crist! I'd say that color scheme was definitiely "in the groove"..!
-
Yeah, I can't seem to get past red, white and blue.
-
A little update. I'm detailing the fuselage front end. Working on both the motor mount and the ESC mount. The motor will have a aft support ball bearing. I should have that done tomorrow.
-
Boy that sure is nice, great job so far! You obviously have some wonderful skills, can't wait to see the finished plane. H^^
-
Jan does great work Crist LL~ LL~ LL~
-
Thanks John. Been building models for a looong time.
Lee,
She is an amazing woman.
-
Tonight I joined the wing to the fuselage. Tomorrow the stab and fillets.
-
Crist:
Inquiring minds want to know: is that an aluminum motor mounting plate? and it is held in..... how?
-
Yes, it is 2024-T3 .090 thick. It is held in by JB-Weld. I notched the plate on the sides where it fits into the slots in the fuselage for added security.
-
Today's progress. The stab and the fin are glued in place and all the fillets are done. Getting close.
-
Looks like test flights next week!
-
Crist, Can you provide some details about the fuse construction? Did it end up the equivalent of 1/2" sq. framework material sheeted with 1/8" balsa sides plus 1/64" ply doublers forward of the wing? I could see that you ran some material - 1/2" square hardwood? - from the very front all the way back to the wing.
Thanks for the build thread. The results look really great!
Jim Howell
-
Crist, Can you provide some details about the fuse construction? Did it end up the equivalent of 1/2" sq. framework material sheeted with 1/8" balsa sides plus 1/64" ply doublers forward of the wing? I could see that you ran some material - 1/2" square hardwood? - from the very front all the way back to the wing.
Thanks for the build thread. The results look really great!
Jim Howell
The front uses basswood that is 3/8 x 1/2 with 3/32 basswood added. Then with the 1/64 plywood on each side the width comes to 5/8 inch. The portion aft and the canopy is 5/16 balsa laminated to equal 5/8 x 1/2. Then whole thing is sheeted with 1/16 balsa. The balsa on the front uses 1/2 balsa with 3/32 balsa to equal the same thickness as the basswood. The total width of the fuselage is 3/4.
-
Today's progress. Hooked up the controls, finished the rudder, and made the pushrod fairing. I didn't get to the "ink" lines. The last picture is a close up of the ESC mount. The close up of the flap horn shows the LH "turnbuckle" of both the flap and elevator pushrods. To adjust either pushrod, all I need is a 3/16 open end wrench and turn the pushrod thus adjusting the length of the pushrod. Thank you Tom Morris!
-
Crist,
Tell us about the fillets. They look good.
Jack Pitcher
-
30 minute epoxy and microballoons. After trowelling the mixture into the corner I use a 3/16 ball bearing that is glued to a dowel to from the fillet. The ball bearing gives a uniform radius no matter what angle it is held at in relation to the fillet. I dip the ball bearing in rubbing alcohol before going over the fillet. After the ball bearing treatment I take a paper towel folded over several times soaked in alcohol and clean up the excess mixture from both sides of the fillet. After a few minutes of setting I dip my finger in alcohol and gently rub the fillet the entire length to get it super smooth. Then another clean up with paper towels and alcohol. Let dry.
The 30 minute epoxy mixture is 2 grams of each epoxy and hardener, 4 grams total. Then I add about 6 "scoops" of microballoons using a popsicle stick with about 1 inch of microballons on it.
-
Your fillet material comes out white, or did you have to paint it to match ?
-
Painted with Nelson Hobby Paint - color - white Monokote
-
Crist,
That plane is just too pretty-pull test your handle! HB~>
-
Crist,
That plane is just too pretty-pull test your handle! HB~>
10-4!
-
Was looking at the first post in this thread.
Why did you change from the 5S/710KV to the 6S/600KV combo ?
-
Was looking at the first post in this thread.
Why did you change from the 5S/710KV to the 6S/600KV combo ?
I heard that 6S has lots of torque and wanted to try it. I flew my Pathfinder ARF with a 6S and 580kv motor. Worked very well. However, I just might go to a 5S set up. Stay tuned.
-
OK, I decided to go with using Thunder Power G6 5S 2700mah Pro Lite batteries. Yeah, they are a bit pricey, but they will give me the best performance and last a long time. They are pretty light too. I save 3 ounces over the 6S batteries and I can use a stock motor rather than having one custom wound. This way everything is "off the shelf" so if I need another motor, I can just buy another one rather than waiting to get one rewound. Also I can use the same batteries on next years full fuselage electric stunter.
With the 6S battery, even with the short nose, the plane was going to balance very nose heavy. Now, it'll be pretty close to spot on.
-
The motor is mounted and front end details completed. All that is left is to add the name and AMA numbers. I'll make up a set or 2 of lines this weekend and set up the control neutral. The battery shown in the pictures is from the plane from 2 years ago. I haven't received the Thunder Power batteries yet. Projected weight is now 55.5 ounces, circle ready.
-
Nice motor installation.
Did you get the rear bearing from Boca ?
What is p/n ?
-
I get my bearings from RC-Bearings. F695ZZ 5x13x4mm flanged bearing.
http://www.rc-bearings.com/catalog/product_info.php?cPath=30_32&products_id=437
-
Time to go over making the letters and numbers. The letter size for this plane is 275pt. I use MS WORD to layout the letters on a paper size of 17x22 inches. The font is Challenge Extra Bold. There are no square outside corners in this font. After printing, I line the back side with clear packing tape. I suppose you can do the front side, but I haven't so far. I trim the template to a height of 5 inches. I then cut a strip of black Monokote 4 inches high the width of the Monokote. I then remove the plastic backing sheet from the Monokote.
Then I tape down at least 4 layers of newspaper down on my bench. Keep the paper smooth and flat. Then tape down the Monokote, shiney side up, to the newspaper. Then finally the template.
I cut the inside of the letters/numbers out first, then the outside edges. I use a #11 blade and hobby knife. Press just hard enought to go through the template, Monokote, and several layers of newspaper. Cutting out the name shown in the pictures took me about 15 minutes total.
Remove the template carefully and discard the extra Monokote and newspaper.
Measure the width of the numbers/letters on the template. Then measure the room on the wing panel. In this case the letters were 14 inches wide and the wing panel was 27 1/2 wide. I subtracted 14 from 27 1/2 and then divided by 2. 6 3/4 was measured in from the root and the tip. A line was drawn on the Monokote with a fine line Sharpie marker. I then measured up 2 inches from the TE for the bottom of the letters.
I then placed the template between the marks and taped the top edge in 3 places. Then I flip the template up over it self and I crease the tape to form a hinge. I then clean the Sharpie markings off and the clean the wing surface with acetone.
Flip the template back down on the wing and then back up. I use Windex to position the letters. I then spray some Windex on the wing in the area of the first letter and spread it around with my fingers. Flip the template down and position the letter in the cutout of the template. Flip the template back up and smooth the letter down using a soft cloth. Flip the template back down and check for proper position. If not I move the letter slightly into position. The reason the template was lined with clear packing tape is that the Windex won't soak into the template while using it. Repeat the procedure for each letter. Remove the template and let the letters dry overnight. Then I use a Monokote iron set at about 1/2 and go over each letter carefully to bond it to the wing.
-
Nice technique for Monokote lettering.
I use Word also to layout the lettering for a spray mask on dope finishes. I like to use a font that has predominately straight lines vs curves because I find them easier to cut out. Curious why you avoid outside square corners.
Also I like to go into the font "Effect" dialog window and change the text to "Outline". Its saves a lot of ink when you print out, and it gives a nice sharp line to follow for cutting.
-
Nice technique for Monokote lettering.
I use Word also to layout the lettering for a spray mask on dope finishes. I like to use a font that has predominately straight lines vs curves because I find them easier to cut out. Curious why you avoid outside square corners.
Also I like to go into the font "Effect" dialog window and change the text to "Outline". Its saves a lot of ink when you print out, and it gives a nice sharp line to follow for cutting.
Square corners can lift.
I'll have to try the outline method next time. Good idea.
-
Ok, the build is finished. I used my Monokote iron on the numbers/letters. I bench set up the controls and made up a new set of lines. Set neutral on the handle. Gave her a coat of wax too. Just waiting for the batteries. After break in, it'll be ready to go later this week.
-
I got a battery (others are on the way) tonight and did the final weigh-in and balance check. The battery is advertised as 292g, mine was 298g. I check the balance point and it was a little too far forward so I added 1/4 ounce to the tail. Total weight now is 55 ounces and the balance point is 23%.
-
Flew it for the first time this evening. 9 1 minute flights getting lap times, wings level, and equal turns adjusted. Still needs more tweaking.
BTW, I got one of Will Hubin's programming box and several FM-9 timers. Well worth the money! Electric stunt is even easier now. I'm running in high governor mode right now because it is easier to adjust RPM to get lap times where I want them. BTW, 1 change of 75 more rpm put me right where I want for lap times....5.2 - 5.3 seconds.
If your flying electric stunt and you're not using Will's stuff, you are making hard on yourself.
Also making the LG 1/2" longer because what I have now will only accommodate a 12 inch prop. After doing some test flying today it looks like I can go to a larger prop and not go over 80% battery capacity.
I have a new flying site that is only 35 minutes away. A coworker lets me fly at his church out in the country. 3 sides are pretty clear with the east side having 4 large trees. 115vac for my charger and picnic tables to pit on. Pretty nice. Fairly secluded too.
-
Beautiful flying site. What is your portable runway made from ?
-
10mm coroplast.
http://www.coroplast.com/
-
Crist, What motor are you using?
-
My set up is listed in post #1. A Scorpion SII-3026-710.
-
OK. I have about 20 flights on the plane. I'm going to post my set up and would like some comments on it.
Scorpion SII-3026-710
CC ICE Lite 50
Thunder Power G6 Pro Lite 25C 5S 2700mah battery
APCE 13x4.5P cut down to 12.5 and pitched up to 5.5 from station 12 on the Prather pitch gauge
56 ounce plane weight
62 foot eye to eye .015 lines
5.25 lap times
10,050 RPM
Phoenix high governor
30 second delay
5 minute 25 second flight time
Governor mode: high
Governor gain: 35
Spool up rate: 6
Head speed change: 6
Battery volts: 18.5
Motor kv: 710
Poles: 14
Gearing: 1:1
Brake strength: 100
Brake delay: 1 second
Brake ramp: very slow
Cutoff volts: Auto lipo
Current limiting: very sensitive
Cutoff type: soft cutoff
Auto-lipo volts/cell: 3.5
Motor start power: medium
Motor timing: normal
Motor direction: forward
PWM: 12khz
Power on beep: enabled
BEC volts: 5.0
Current firmware: v3.26
I used about 2100mah on tonight's flights. The wind was calm. Battery usage was about 78%.
I'm a little concerned that I'm using a bit more battery than I thought that I would. I see others using the same prop and basically the same combo but drawing a lot less from the battery. The other day when it was windy (13+ mph) I was using about 2000mah running 10,500 rpm but with the stock pitch of 4.5. I thought that was a little too high of RPM that I really wanted to run at. With the prop repitched to 5.5 at station 12, 10300 rpm gives me 5 second laps and good wind flying.
I'm enclosing a graph for what ever it would be worth.
The graph doesn't show the numbers on the bottom. They are:
Voltage: min 17.4, max 20.9, ave 18.7
Current: max 32.1, ave 18.7
Amp hours: ave 1.0, max 2.1
Watts: ave 345, max 641
RPM: ave 8339, max 10163
Power out: ave 65, max 85.5
Next time out I'll try varing the PWM down to 8khz to see what effect that would have.
BTW, the temp were:
Motor: 105 degrees f
Battery: 115 degrees f
Outside air temp: 65 degrees
Comments?
-
Crist,
Way too much of a newbe to make comments on your "set-up", but...
I did notice that you changed your PWM from "outrunner" to "12 khz". Oddly enaugh, while discussing my future setup with Bubba he made the same suggestion.
Now my question...What's PWM? Why make this change?
Ward
-
Ward,
PWM is the speed in which the speed controller communicates with the motor, I think. Stands for Pulse Width Modulation.
Reading the Castle Creations Forums, the "Outrunner" setting shouldn't be used for our needs. I forget what that particular setting is really for, but for us 8khz or 12khz should do.
Here is quote from RCGroups Castle Creations, for what its worth :
Quote:
This may have been asked before but what exactly does "outrunner" mode do?
As I recall it’s a variable PWM mode that is needed for very high pole count motors at high RPM to keep the commutation frequency from exceeding the PWM frequency. From my experience it decreases efficiency and smoothness for low pole count motors where it’s not needed. Personally I don’t think it should be the default and CC should change it.
-
I was talking to Floyd Layton today and we were discussing how the Protroma seems to hunt. We were talking about thrustlines, incidences, etc. Floyd talked about some guys use a little bit of slop. That reminded me of what I did for the Resolve, my previous electric profile. So I did the same thing for the Protroma.
I used a Great Planes 4-40 ball link. It is the same length as the Rocket City #87? links commonly used. I then pushed out the ball using a pair of round nose pliers. Then I screwed the ball link on the threaded end of the pushrod.
I cut a piece of 5/32 O.D. brass tubing to a length of 3/16. The brass tubing od is smaller than the hole in the ball link. This difference provides a small amount of slop. Seeing the link is riding on a 5/32 diameter shaft, there is very little chance of wearing it out. Here are 2 pictures that show the installation. Very easy.
-
Crist,
Thx. I am so buried in info right now I never saw that one!
W.
-
OK. I have about 126 flights on the plane. I'm going to post my set up.
Scorpion SII-3026-710
CC ICE Lite 50
Thunder Power G6 Pro Lite 25C 5S 2700mah battery
APC 13x4.5EP /thin hub version
56 ounce plane weight
62 foot eye to eye .015 lines
5.25 lap times
9,553 RPM
Phoenix high governor
30 second delay
5 minute 20 second flight time
Governor mode: high
Governor gain: 50
Spool up rate: 20
Head speed change: 20
Battery volts: 18.5
Motor kv: 710
Poles: 14
Gearing: 1:1
Brake strength: 100
Brake delay: 1 second
Brake ramp: very slow
Cutoff volts: Auto lipo
Current limiting: very sensitive
Cutoff type: soft cutoff
Auto-lipo volts/cell: 3.2
Motor start power: medium
Motor timing: normal
Motor direction: forward
PWM: 12khz
Power on beep: enabled
BEC volts: 5.0
Current firmware: v3.28
I flew it tonight with the proper thin hubbed 13x4.5EP prop. Working very well. Notice that I have the governor gain as high as it will go along with the head speed change and initial spool up rate set to their max (20). When I'm flying, you can hear the motor "singing" or "ringing". You cannot hear any change in the rpm throughout the flight. Very strong running set up.
-
I was talking to Floyd Layton today and we were discussing how the Protroma seems to hunt. We were talking about thrustlines, incidences, etc. Floyd talked about some guys use a little bit of slop. That reminded me of what I did for the Resolve, my previous electric profile. So I did the same thing for the Protroma.
I used a Great Planes 4-40 ball link. It is the same length as the Rocket City #87? links commonly used. I then pushed out the ball using a pair of round nose pliers. Then I screwed the ball link on the threaded end of the pushrod.
I cut a piece of 5/32 O.D. brass tubing to a length of 3/16. The brass tubing od is smaller than the hole in the ball link. This difference provides a small amount of slop. Seeing the link is riding on a 5/32 diameter shaft, there is very little chance of wearing it out. Here are 2 pictures that show the installation. Very easy.
Did the play solve the hunting. I know it works lots of times, but always felt like using play is just compensating for another problem. Did you try motor downthrust? Do you use stab incidence when building or not.
-
Allan,
I did take out the "play" and it didn't really help. I put it back in for the NATS. When I got home I rechecked the thrust line and added a bit of downthrust (actually very close to zero thrust) and that seemed to help. I always use .25 degrees positive stab incidence when building.
-
Whoa
The idea of the positive incidence in the stab is to counter the prescession effects. With a pusher prop the precession effects are reversed - and thus the incedence should be negative, not positive.
You might want to try a tractor porp on it just ot see if it has any effect on hunting. If it does, then..... Retrim or rebuild might be in order.
-
Dennis,
The positive incidence is mainly so I don't go negative when building.
I'll try the tractor prop and see what happens. Thanks for the suggestion.