Author Topic: Another electric success story (Read 7939 times)

Jason Greer · « **on:** August 24, 2009, 09:28:35 AM »

I have been lurking here for a while now and soaking up all the information available. I started building a purpose designed electric stunter several months ago. Yesterday was the maiden voyage for it. To say i'm happy with the results is an understatement.

Here are the stats on my model:
wingspan: 53"
weight: 43 ounces
area: 575 sq"
motor: scorpion 3020 890 (edited as I initially typed 3026, but it should be 3020)
esc: phoenix 35
timer: hubin fm-2a
battery: 4s thunder power 2600 prolite v2
prop: apc 12x6 tractor(originally 12x4 apc cut from 13x4)
rpm: 8400(originally 9900)
lap time: 5.3(originally 5.

lines: 64' .012 solids
flight time: 5:50 using about 1720 mah (edited from 1600)

Jason Greer · « **Reply #1 on:** August 24, 2009, 09:33:54 AM »

Here is another picture:

Archie Adamisin · « **Reply #2 on:** August 24, 2009, 09:53:53 AM »

Jason,

Congrats on the new Bird!!! It really looks nice. Very good weight for that size. Was that lap time really 5.8?? Sounds a bit slow for that rpm. I can't wait to hear more of your results. I am even happier to hear about how happy you are with it.

Take Care!!

Archie Adamisin
Muncie, Indiana

Alan Hahn · « **Reply #3 on:** August 24, 2009, 10:14:12 AM »

That is impressive--especially the relatively low power consumption (everyone knows I like that

).

I am even more impressed because the prop is turning at 9900 rpm, and I had thought that wouldn't be very efficient--but you learn something almost every day.

Crist Rigotti · « **Reply #4 on:** August 24, 2009, 11:04:47 AM »

Jason,
Excellent work! 43 ounces too! I have to ask is that with the battery? Details please. Ya done good.

Jason Greer · « **Reply #5 on:** August 24, 2009, 12:21:05 PM »

Thanks for the kind words guys. My success is due 100% to you guys sharing your information on these boards.

Archie,
I have not checked the rpm with a tach, but I 'm running the esc in set rpm mode at 9900 for all three rpm settings. The lap times really are 5.8 and i'm amazed at the line tension in the overheads.

Alan,
I am amazed at how well the cut down 13x4 is working. The 13x4 has a much wider blade than the 12x6 and I think that may be helping with its efficiency. It pulls like a tractor even in the overheads. I think my low flying weight is helping with the power consumption. Also, the wind was blowing 8-10 yesterday and I'm sure that eased the load a bit.

Christ,
Thank you very much. I dont know if you remember me or not, but I picked your brain one day at the nats. Seeing your model fly really lit a fire under me to get this thing finished up. 43 ounces does include the battery. The wing is an I-beam and I was very careful with wood selection. The top and bottom turtledeck were molded from two layers of 4lb balsa. The entire bottom "block" weighed 10 grams if I remember correctly. I also used monokote to save on finishing weight. The thunder power 2600 only weighs 240 grams so that saves several ounces. I probably could have saved another 1/2 ounce or so because the fuselage sides have 1/32" ply doublers from the spinner back to the trailing edge of the wing. I dont know that I'd want to give up the structural integrity that the ply adds though. I may go to 1/64" ply on the next one.

Also, I forgot to mention that the temps were very mild after the 5:50 flight. I forgot my ir thermometer, but I would estimate the motor at 110-120 and the battery was just barely above ambient air temp. I could hold my finger on the motor. Next time I will have my thermometer. The summer temps here in south Arkansas are very mild right now. The high yesterday was about 90. We are normally close to 100 this time of year, but even at 100 I dont think I would have a heat problem.

If I can provide any more details just ask and I'll try to answer them.

Thanks,
Jason

Archie Adamisin · « **Reply #6 on:** August 24, 2009, 12:41:21 PM »

Sounds to me like you have it set up just right then. I haven't tried the 13 x 4, but I have plans for (1) soon. Have you flown it in any wind yet? If your grinning now, you will be dancing then. I would suggest that you try to find some pusher props to try as well. It makes a difference in the verticals, hourglass, and the 3rd loop of the clover. We really need to push on APC to make us a better selection of props.

Great job on you new model. I hope to get to see you fly it sometime.

Archie Adamisin
Muncie, Indiana

Crist Rigotti · « **Reply #7 on:** August 24, 2009, 01:12:40 PM »

Jason,
Yes I remember you now. I just looked at the plane and not the pic of you holding the plane. Once you get your set up working for you please post it in one of the "stickies". Please keep us posted as to your progress.

Dennis Adamisin · « **Reply #8 on:** August 24, 2009, 01:22:50 PM »

GREAT job Jason, and congrats on your successful tests. Like Crist mentioned, post it in your "List your set-up" thread, then update that listing if/when you change things - but it sounds like you are pretty happy already.

Now go practice some more...

Crist Rigotti · « **Reply #9 on:** August 24, 2009, 03:45:21 PM »

Jason,
How many cells is the battery? 4S? How about some pictures of the innards? How you mounted the motor, battery, timer, etc.

Jason Greer · « **Reply #10 on:** August 24, 2009, 03:56:20 PM »

Christ,

It is 4s. I knew I would forget something important.

I will take some pictures with the cowling removed tonight and get them posted.

Jason

Crist Rigotti · « **Reply #11 on:** August 24, 2009, 04:52:09 PM »

Thank you Jason. Your airplane has gotten my interest peaked. There is hope my next years plane will come in even lighter than the 51 ounce Resolve EP.

Jason Greer · « **Reply #12 on:** August 24, 2009, 08:14:45 PM »

Crist,

Here are some pictures of the interior and cooling setup. The second picture shows my rudimentary rear bearing support. It is riding in a 1/2x3/8 maple block and bolts in so I can remove the motor. I will have to come up with something more permanent in the future. The third picture shows the motor cooling intake on the top of the fuselage just behing the spinner. The air is forced over the motor and exits at the rear of the cowling. The fifth picture shows the cooling intake for the battery. The last picture shows the cooling exit at the rear of the cowl.

Also, I have to correct a mistake in my initial post. I just recharged the battery after yesterdays last flight of 5:50 and it took 1720 mah. I suppose the 1600 was from an earlier shorter test flight. Even at 1720 I feel that is quite acceptable power consumption.

Thanks,
Jason

Crist Rigotti · « **Reply #13 on:** August 24, 2009, 09:17:30 PM »

Thank you Jason. Your work is impressive. Why did you settle on the 3026-890 and not the 3020-890? I'm just curious because your set up is working well. Thanks for sharing. We can all learn from each other. BTW, what is the design? Is it yours? Very nice design. What is the thickness of the airfoil?

andreas johansson · « **Reply #14 on:** August 25, 2009, 02:39:14 AM »

Jason,
You really seems to have hit the spot with your model. Congrats to your success

Its also a very beautiful model

Now myou only need to make plans of it so the rest of us can copy your success.

/Andreas

Archie Adamisin · « **Reply #15 on:** August 25, 2009, 06:24:56 AM »

Jason,

What a great installation!! I can see that you put a lot of thought into your construction and placement of equipment. Great work!! This means you have been listening to all of us hash out and move toward true electric design ans construction. I can't wait to see it in person. With the temps you haev measured, I would say that the cooling is more than adequate especially with the warmer temps you are flying in. What kind of settings do you have on your Castle controller? Have you been able to mess with some of the governor functions like gain and head speed change rate? What timing are you set at? Have you played with the PWM? You are running a lower pitch set-up than most of us and I am curious. I have found that the higher RPM runs better at higher timing settings and higher PWM. Learned this by using the same motor that my uncle Dennis uses in Mythbuster in an RC Pylon racer. I put a 9 x 7.5 prop on it at the highest timing setting and it went over 120 mph and ran like a watch. What revision of firmware are you using?

Sorry about the barrage of questions, but I think I speak for all of us that we are excited about you success. Keep burning those electrons!!!

Take care!

Archie Adamisin

Crist Rigotti · « **Reply #16 on:** August 25, 2009, 06:39:53 AM »

Do I see magnets holding on the aft portion of the hatch? Why a CC-35 instead of a CC-45? Questions, questions, questions.

Archie Adamisin · « **Reply #17 on:** August 25, 2009, 07:40:18 AM »

Crist/Jason,

Uncle Dennis and I both use phoenix 35's in Oriental (3S), Vector (4S), Mythbuster (4S), and Swinger (4S). I talked with Pat @ Castle at the Toledo Show about controller size and he wondered if we considered using the 25 because our average current was so low that the 25 would be more than sufficient. The weight of the 25 is really attractive.

I think its a matter of cost and weight. If you can buy a 45 for the same price as a 35, it's a no brainer. I believe you & Alan have gotten some 45's this way. (Hook me up with your supplier!!!!) I bought a 60 initially because I wanted to have lower controller resistance, (actually first flew with a 80 I borrowed) but really that doesn't show up significantly unless you are at the rated current for a prolonged length of time. If the ICE series controllers take off, then the phoenix controllers should get really cheap. The ICE 50 @ $85 is a real bargain @ the same price I bought my first 35 for.

Take Care,

Archie Adamisin
Muncie, Indiana

Jason Greer · « **Reply #18 on:** August 25, 2009, 07:42:28 AM »

Crist,
I was wrong in typing 3026 890, it is indeed a 3020 890. I chose the 3020 890 due to the success you've had with yours. I really should have had my morning coffee before typing out my initial post... The hatch is indeed held down with magnets. I am going to add a couple more at the front for more security. I wanted an easily removable hatch for battery access. The CC35 was chosen basically because I got a great deal on one and I figured it would have plenty of overhead for current. I am pulling about 29 amps static on the ground so I would think it would go down a bit in level flight. I really need to get some type of data logger.

The airframe is my own design. I copied the side profile looks from the Geo XL. The wing and stab are my own layout. The stab volume is 22% of the wing area. The airfoil is 2" thick at the root. I dont remember the root chord off the top of my head so I dont know the percentage. I started out with the CG at 22%, but I have moved the battery forward 1/2" so I am probably closer to 20% now.

Archie,
Thanks for the compliments! I spent several nights in the shop just staring at my plans trying to figure out a solution to get as much airflow across the motor and battery as possible. The motor cooling was the most difficult for me to design as it is completely hid behind the spinner from any direct airflow. Coming in from the top and exiting out the bottom was the only feasible solution I could come up with and I kind of like the looks of the scoop on the top.

I'm just going off of memory here, but I'm pretty sure I have the govenor set to high gain and medium head speed change. I have not changed the timing or PWM from defaults. I am running revision 2.11 on my CC35. I am holding off from the newest version after reading about Crist's issues with the latest version.

Andreas,
Thank you! Like I said earlier the success of this model is due completely to the information posted on these boards. My plans are just pencil drawings on the back of some other old drawings I had from previous builds. I would like to get them into CAD some day.

Jason Greer · « **Reply #19 on:** August 25, 2009, 07:37:53 PM »

Here is the detail of my current CC35 settings:

Hex55: 85
Brake Strength: 50
Brake Delay: .6 sec (Delayed) (*)
Brake Ramp: Immediate (*)
Cutoff Voltage: Auto Li-Po (*)
Current Limiting: Normal (*)
Cutoff Type: Hard Cutoff (*)
Motor Start Power: 59
Direction: Forward (*)
PWM Rate: 12 Khz (*)
Vehicle Type: Control Line
Throttle Type: Governor Mode
Throttle Response: 5
Governor Gain: 21
Initial Spool-Up Rate: 8
Head Speed Change Rate: 5
Auto Rotate Enabled: False
Governor Mode Type: Fixed
Vehicle Setup - Battery Type: LiPo
Vehicle Setup - Number of Cells: 4
Vehicle Setup - Battery Voltage: 14.8000
Vehicle Setup - Gear Ratio: 1.000
Vehicle Setup - Motor Kv: 900
Vehicle Setup - Motor Number of Poles: 14
Desired Head Speed 1: 9920
Desired Head Speed 2: 9920
Desired Head Speed 3: 9920
Motor Timing: 5
Power-On Beep: Enabled (*)
Auto-Lipo Volts/Cell: 3.0 Volts/Cell (*)

bob branch · « **Reply #20 on:** August 26, 2009, 05:56:56 AM »

Hmmmm,Another film covered I-beamer. Mythbuster is also one and I think Dennis' classic plane may have been one as well. Seems like another myth may go by the wayside from the electric fraternity. Golly we are a sacrilegious bunch!

bob branch

Dennis Adamisin · « **Reply #21 on:** August 26, 2009, 06:27:38 AM »

Quote from: bob branch on August 26, 2009, 05:56:56 AM

Hmmmm,Another film covered I-beamer. Mythbuster is also one and I think Dennis' classic plane may have been one as well. Seems like another myth may go by the wayside from the electric fraternity. Golly we are a sacrilegious bunch!

bob branch

The line it is drawn, the curse it is cast
The slow one now, will later be fast
As the present now, will later be past
The order is rapidly fadin'.
And the first one now, will later be last
For the times they are a-changin'.

Jason Greer · « **Reply #22 on:** August 26, 2009, 12:34:30 PM »

Well I went out today at lunch and squeezed in one flight. On the vertical up line after the first outside loop of the cloverleaf I lost all line tension and had to run to regain control. I think I am going to add another 300 rpm to get the speed up a little. That will put me at 10,200. Currently I'm flying at 5.8 seconds. I'd really like to be around 5.5 seconds. I really wish I had a 12x4.5 or 12x5. I dont have a pitch gauge so I'm not setup to repitch props. Do you guys think 10,200 is going to be to close to full throttle and prevent the governor from holding the rpm constant as the flight progresses and the voltage drops?

Dennis Adamisin · « **Reply #23 on:** August 26, 2009, 01:07:50 PM »

Change to the 11x5.5 prop, drop the RPM to 9400, expect about a 5.1-5.3 lap time. Fine tune to suit...

Jason Greer · « **Reply #24 on:** August 26, 2009, 01:31:00 PM »

Thanks Dennis. I will try that. I have an 11x5.5 to try.

Alan Hahn · « **Reply #25 on:** August 26, 2009, 01:33:57 PM »

Quote from: Jason Greer on August 26, 2009, 12:34:30 PM

Well I went out today at lunch and squeezed in one flight. On the vertical up line after the first outside loop of the cloverleaf I lost all line tension and had to run to regain control. I think I am going to add another 300 rpm to get the speed up a little. That will put me at 10,200. Currently I'm flying at 5.8 seconds. I'd really like to be around 5.5 seconds. I really wish I had a 12x4.5 or 12x5. I dont have a pitch gauge so I'm not setup to repitch props. Do you guys think 10,200 is going to be to close to full throttle and prevent the governor from holding the rpm constant as the flight progresses and the voltage drops?

You can always fudge one. Most people I think are only tweaking the prop near the hub, so the whole blade is changed by the same angle.

What I would do is choose some radius--like 5" out, and measure the angle you have with the current prop (cut a triangle out of balsa or something or buy a cheap angle measuring from the hardware store. Then do the same with an APC 12-6 electric. Now heat the hub of your modified 13-4 and tweak the prop to be somewhere between where you started, and where the 12-6 is (at 5" radius). Now get the other blade to be the same. Should be good enough for a try.

Crist Rigotti · « **Reply #26 on:** August 26, 2009, 01:41:25 PM »

Jason,
9600 rpm should put very near the 75% mark of full rpm. I would think that 9600 to 9800 is a good place to be. I know, I know, I'm only running 9100 rpm.

Jason Greer · « **Reply #27 on:** August 26, 2009, 02:40:13 PM »

Alan, Thats a good idea. I think I will try to increase the pitch of the 12x4 just a little. Would a monokote heat gun work to heat the hub?

Crist, I will repitch and shoot for 9600 rpm. I knew I was getting into the upper limit of where I needed to be with the 12x4.

Alan Hahn · « **Reply #28 on:** August 26, 2009, 03:18:46 PM »

Quote from: Jason Greer on August 26, 2009, 02:40:13 PM

Alan, Thats a good idea. I think I will try to increase the pitch of the 12x4 just a little. Would a monokote heat gun work to heat the hub?

Crist, I will repitch and shoot for 9600 rpm. I knew I was getting into the upper limit of where I needed to be with the 12x4.

I think so, but I think Crist and others are more expert on prop tweaking than I am. I think someone has detailed how to do it here in the electric section.

ahhh, here is the link.

http://stunthanger.com/smf/index.php?topic=12142.0

Jason Greer · « **Reply #29 on:** August 26, 2009, 03:36:41 PM »

Thank you very much for providing that link. I had not seen that particular post. I think I will try to increase the pitch of the 12x4 tonight and test tomorrow. Hopefully I will have some improvement to post afterwards.

Thanks to everyone for the information!!

Matt Colan · « **Reply #30 on:** August 26, 2009, 03:37:56 PM »

Lookin good Jason!

Jason Greer · « **Reply #31 on:** August 26, 2009, 03:42:34 PM »

Thanks Matt!!

Larry Wong · « **Reply #32 on:** August 26, 2009, 04:09:05 PM »

Jason TRY a (APC 12X6 EP) pusher and reverse the direction on you motor, you might be surprize on the line tension. TRY it you might like it , that all I use, your plane looks great, do you have the weight on it?

Crist Rigotti · « **Reply #33 on:** August 26, 2009, 04:20:24 PM »

Larry,
The APC 12x4 EP? Where are these listed?

Larry Wong · « **Reply #34 on:** August 26, 2009, 04:38:40 PM »

Crist I found it in the local E- Hobby shop, but I think it is also in the APC web site.
http://www.apcprop.com/pindex.asp

Crist Rigotti · « **Reply #35 on:** August 26, 2009, 06:26:17 PM »

Larry,
Forgive me but I can't find it on the link you provided.

Larry Wong · « **Reply #36 on:** August 26, 2009, 07:04:12 PM »

Crist Look under LP12060EP 12x6 EP Woops Senior moment I ment 12x6 EP Sorry

Jason Greer · « **Reply #37 on:** August 26, 2009, 08:55:10 PM »

I went out tonight and got 2 short test flights in. I didnt have my 11x5.5 with me so I put the 12x6 on and set the rpm to 8600. On the first flight I was flying 5.0 second laps and the plane was flying much better, but a little fast. The next flight I reduced the rpm to 8400 and the lap times went to 5.2. It felt great at that speed. Line tension was wonderful and the plane just grooved better. According to castle link 8400 is the minimum rpm I can run for proper governor operation with this motor. My next experiment is going to be to make a new set of lines at 64 feet eye to eye and see how it feels. I'd really like to be around 5.3-5.4 second lap times as that is what i'm used to flying at. Both flights total flight time was 4:30 and I also ran for about 15 seconds on the ground with the watt meter and to verify the rpm with a tach. The battery took 1400 mah afterwards. So I still expect around 1700 mah for a 5:30 flight time which is equal to what I was using with the 12x4.

My second battery came in this afternoon so tomorrow I am expecting to get two full pattern flights in and I'll report back with the results, but right now I'm quite pleased with the 12x6 at 8400 rpm.

Once again thanks very much for all the input!!

Dean Pappas · « **Reply #38 on:** August 26, 2009, 09:09:22 PM »

Quote from: Dennis Adamisin on August 26, 2009, 06:27:38 AM

The line it is drawn, the curse it is cast
The slow one now, will later be fast
As the present now, will later be past
The order is rapidly fadin'.
And the first one now, will later be last
For the times they are a-changin'.

I dunno, Dennis ...
A handful of weeks ago it was Sager and Evans, now Dylan.
By the way, Gang, the word from the Pattern Worlds going on right now is that between 70 and 80% of all competitors at the worlds are E-powered.
Indeed, the times they are a-changin'.

later,
Dean P.

Matt Colan · « **Reply #39 on:** August 27, 2009, 03:12:28 PM »

Quote from: Jason Greer on August 26, 2009, 03:42:34 PM

Thanks Matt!!

Your Welcome!

Jason Greer · « **Reply #40 on:** August 27, 2009, 08:16:45 PM »

Got two more full flights in this afternoon. I made up a set of 64' lines to try and am very happy with the results. Lap times are now 5.3 seconds with the 12x6 at 8400 rpm. Line tension was great everywhere and the speed is right where I want it. I am recharging the batteries now to see how much power was consumed. I can now say that I have the power system and airplane flying exactly how I want. Now I just need to concentrate on flying. I will be flying the model in Dallas next weekend in its first contest. I'm really excited as this is the best flying model I've ever built.

Jason

Crist Rigotti · « **Reply #41 on:** August 27, 2009, 08:21:18 PM »

Jason,
That's great news. That's another plus for electric, it doesn't take long to get the motor dialed in. Good luck in Dallas.

Dennis Adamisin · « **Reply #42 on:** August 27, 2009, 09:25:13 PM »

Virtually plug & play. BTW kudoes to your Photog for the great in-flight shot

Jason Greer · « **Reply #43 on:** August 28, 2009, 07:09:03 AM »

Thanks guys. After recharging both battery packs last night I put 1630 mah in one and 1640 mah in the second. Each flight was 5 minutes and 30 seconds. I am extremely pleased with this as that is only about 63% usage of the battery.

Crist Rigotti · « **Reply #44 on:** August 28, 2009, 07:19:40 AM »

Super!

Alan Hahn · « **Reply #45 on:** August 28, 2009, 07:40:43 AM »

Quote from: Jason Greer on August 28, 2009, 07:09:03 AM

Thanks guys. After recharging both battery packs last night I put 1630 mah in one and 1640 mah in the second. Each flight was 5 minutes and 30 seconds. I am extremely pleased with this as that is only about 63% usage of the battery.

aaaaaah, the magic 12-6 prop!

Crist Rigotti · « **Reply #46 on:** August 28, 2009, 08:14:35 AM »

Jason,
When you get the chance try an APC 12x6EP pusher prop. Add about 300 rpm when using the pusher prop. Let me know how you like the overheads, clover and the hourglass.

Jason Greer · « **Reply #47 on:** August 28, 2009, 09:02:05 AM »

Alan,
The 12x6 is definately magical.

It works great!

Christ,
I will pick up a 12x6 pusher and give it a try. Will the pusher require cutting the spinner for fitment?

Jason

Crist Rigotti · « **Reply #48 on:** August 28, 2009, 10:13:06 AM »

Quote from: Jason Greer on August 28, 2009, 09:02:05 AM

Alan,
The 12x6 is definately magical. It works great!

Christ,
I will pick up a 12x6 pusher and give it a try. Will the pusher require cutting the spinner for fitment?

Jason

Yeah the spinner will have to be cut. You can try it without the spinner cone first?

Jason Greer · « **Reply #49 on:** September 07, 2009, 06:46:06 PM »

Well the Omega has been through its first contest and my first contest flying at the advanced level. The model and power system are working great, but my piloting skills need serious improvement. I finished 5th out of a field of 12. My model was the only electric at the event and everyone seemed really impressed with the performance. Many questions were asked and I gave my contact information to several people. I also referenced them to this site.

Author Topic: Another electric success story (Read 7939 times)

Alan Hahn

Alan Hahn

Alan Hahn

Alan Hahn