Author Topic: Help with an Electric Stunter (Read 1772 times)

Shawn Lenci · « **on:** December 11, 2009, 04:48:26 PM »

Hello,

I have been lurking on this forum for a couple a year and am looking to get back into flying stunt, but this time I want to go electric power. I can see far more positives to this approach to flying than negatives with the two biggest for me being no noise and no oily clean up. Here is what I am looking at, please tell me what you guys think. The motor I have purchased it a Hacker A30-10XL (650 watts and 900Kv). I am looking a using one of Randy Smith's Majic carbon 3 blade props. A 12 X 6.5 3 blade or the 11 X 5.5 3 blade. I am going to run this on 4S power with Hubin timer. Do you think this motor/prop combination would pull a Trivial Pursuit or and SV-11 or an airplane of that size, 650-675 sq inches? Do you think these kits could be sucessfully converted to electric power? I want to build a ship that has access to the battery on top of the fuse like so many of today's R/C electric ships. I most likely will cover the airplane in film covering as I do not want to put a ton of time in the finish. I want to fly this thing!

I have lots of ideas but cannot afford to buy lots of parts to experiment with so any help would be appreciated. Let me know what you guys think.

Shawn Lenci
Escalon, CA

William DeMauro · « **Reply #1 on:** December 11, 2009, 05:10:11 PM »

Do you think these kits could be successfully converted to electric power? I want to build a ship that has access to the battery on top of the fuse like so many of today's R/C electric ships.
I don't only think those planes can be converted. I KNOW THEY CAN!!!! Read the thread on my SV11 it has just about all the things that you are looking for in E Stunt. http://stunthanger.com/smf/index.php?topic=11132.0
William

Howard Rush · « **Reply #2 on:** December 11, 2009, 06:47:39 PM »

Hi, Shawn, welcome back.

Dennis Adamisin · « **Reply #3 on:** December 11, 2009, 07:05:00 PM »

Shawn:
First off, WELCOME to ECL. I will vouch that Will D's SV-11 is an awesome set-up, and probably right in the "sweet spot" you are talking about. ALso, Bob Branch did a great build thread on the T-Rex.which is a natural for electric conversion.

About props: THe APC electric series props are about the best anywone has found - More importantly, look for a PUSHER or LH rotation prop. Everyone I know of who has tried one reports improved line tension - especially on the tops of Vertical 8s and Hourglass. I would suggest the 13x4.5P running about 10x300 RPM.

Hacker motors have an outstanding reputation - but I am not familiar with the sizes so do not know what the equivalent AXI, Arrowind or Scorpion would be so I do not know how to compare it to some of the birds described in the "List your Set-ups" thread.

You did not mention your ESC???

Shawn Lenci · « **Reply #4 on:** December 11, 2009, 09:23:51 PM »

William...thanks for pointing me to your SV-11 build. The one thing that concerns me on these airplanes is being able to get the battery pack back far enough to balance the airplane. I was surprised to see that you did not have to move it back into the wing to make it work. A very nice looking ship indeed. You give me hope!

Howard...I met you a couple of years ago at the Golden State contest. Thanks for the welcome back! I love all your writings....especially about being "Bad and Nationwide."

Dennis...Thanks for the advice as well..You seem to be one of the guys that is doing a lot of experimentation with this stuff and are getting good results with less expensive gear. I leaning towards the Majic props because I felt that "carbon" had to be better. I keep being amazed how people keep coming back to the APC 12X6 EP. I really like idea of the pusher though...It makes total sense. In my full scale flying everytime the nose pitched up the plane wanted to yaw left. This is exactly want we don't want in stunt. I do a lot of electrics in RC and I have a buddy that molds his own carbon props for high performace F5B airplanes. We talking 30,000 rpms+. We have been talking a lot and I might have him help me mold some pushers when I get going more on this project. Is the 13X4.5P the one you had APC custom make? Sounds good. As far as the ESC goes I'll probably go with the Castle or a Hacker. Although my buddy hates Castles for RC. He thinks they overpriced and burn up faster than Turnigys. I really don't have an opinion. Your recommendations would be?

Thanks again guys!

Shawn

Archie Adamisin · « **Reply #5 on:** December 12, 2009, 06:03:08 AM »

Shawn,

Actually, we have found that we have had to lengthen the nose going to ECL to get proper balance. It also give the ability to adjust CG.

I have never heard that Castles burn out faster than Turnigy's. I do like Turnigy's for R/C as they are affordble, but the Castles aren't that expensive and for what they can do, you really can't beat them. ICE 50 for $84.99 and it has a built in data logger? No one on the market has anything for that right now.

I did Beta testing on the Castle Phoenix ICE 50 and put it through some very detrimental testing and never failed it. I ran it on 6S and over 70 amps and it held up just fine. In F5B, I can see that failures would come, but not in the newer generation controllers. They should be using the Phoenix HV 200 amp controllers that quite frankly I don't see how you could blow them up.

The Hacker ESC has a Governor or hold RPM mode that should work fine. I haven't run any of their new ESC's so I couldn't tell you where to begin. The A30-10XL motor you selected should do the job. Personally, I would have gone with the -12XL, but the 10 will work. Try to keep your weight under 60 ounces. Find where the motor seems to be happy and then adjust your line length to bring in your lap time.

As far as props, don't be fooled into thinking that because it is carbon, it is better. We have flown from the 9 x 4.5 to the 13 x 6.5 APC "E" props and all of them work great. It is all about the blade shape. Mezilik props are great glow props. Electric props need to be different to take advantage of their torque properties.

I look forward to hearing how your project goes.

Archie Adamisin
Muncie, Indiana

Dennis Adamisin · « **Reply #6 on:** December 12, 2009, 07:03:54 AM »

Shawn:
Hacker makes first rate stuff but I do not know HOW that extends to their ESC. The closest thing to a "knock" I can come up with on the Hacker ESC is that no one here (that has posted) has any experience or can help you with it - you might be trail blazing. RSM includes a Hacker ESC & Motor in their "turn-key" power system - you might be able to get some help there.

If you use the Castle or Shulze ESC's then you could get some help/advice here.

Yes I got the 13x4.5P's special ordered out of APC and (after rounding up orders here) bought the initial 200 prop sample. I still have about 50 left - @ $7.50 per plus shipping. (hint hint!)

Shawn Lenci · « **Reply #7 on:** December 12, 2009, 08:36:47 AM »

Archie,

I am surprised to hear that people have actually been lengthening the noses to get these things to balance. Good to know. I most likely will go with the ICE 50 controller. I have no issues with them having used a couple of Phoenix controllers in my park flyers. The real plus is that there is a lot of experience here to help out if I have any questions. I went with the Hacker A30-10XL (actually bought it used for $60) as that is what RSM has in there "turn key" set up. I figure it was around 900Kv and that looked about the same as what most guys are using. Why do you recommend the -12XL? Wouldn't that Kv be around 700 or so? I may get one of those as well just to try it out.

I think I am going to get an RSM Trivial Pursuit to do this build with. I fly here in Northern CA in the Central Valley just east of the Bay Area. I think there may be a few guys locally that would be able to help me trim it out! What do you think?

I do like the idea of using APC props from a cost standpoint. I keep seeing everyone using them so they must work well.

Dennis,

Send me a PM on what the total would be for 3 of your props with shipping to CA. I'll give them a try.

William DeMauro · « **Reply #8 on:** December 12, 2009, 09:54:30 AM »

William...thanks for pointing me to your SV-11 build. The one thing that concerns me on these airplanes is being able to get the battery pack back far enough to balance the airplane. I was surprised to see that you did not have to move it back into the wing to make it work. A very nice looking ship indeed. You give me hope!

Shawn,
When I started this project I thought the exact same thing. Boy was I fooled!! But also keep in mind that I fly my planes a bit more nose heavy than most others. I actually use those "big,heavy,overweight flightmmax batteries" in it to get it to balance but it works fine and gives me what I need. Good luck with this project and keep us informed.
William

Mike Scholtes · « **Reply #9 on:** December 12, 2009, 12:33:53 PM »

Hi Shawn:

I am in Alameda, next to Oakland, and there are several electric power CL guys in the East Bay. Larry Wong who posts here is (I think) in San Leandro and is probably our most experienced ECL person locally. As you may know by now there are lots of flyers in the Santa Clara-San Jose area who regularly fly at Gilroy. Larry Fernandez of San Jose is an awesome builder and excellent coach. Brett Buck in Santa Clara is one of the country's preeminent trim experts and is most helpful with advice. You also have several flyers in the Central Valley that you may already know. You will not have any trouble finding first-rate help in Northern California. Look forward to seeing you at the field, if I haven't already! I am no expert but am putting together an EP China Clipper, 690" and have gotten great guidance on this forum.

Archie Adamisin · « **Reply #10 on:** December 13, 2009, 08:49:03 AM »

Shawn,

I thought there was a higher Kv A3012XL than 700. I just checked the website and you made the right choice. It will work great.

As far as design, there aren't many current or even classic designs that wouldn't make great ECL models as is. My new designs I have extended the nose an inch to give more room to adjust CG. Have never really had an issue with too nose heavy yet.

Archie Adamisin
Muncie, Indiana

Mark Scarborough · « **Reply #11 on:** December 13, 2009, 11:22:44 AM »

The A30 10XL is a solid motor, and compares with the Axi 2826 performance and power. I have a Hacker A30 8Xl that is going in my next electrc stunter, the plan is for a more "pipe " style run, higher rpm, lower pitch.

Shawn Lenci · « **Reply #12 on:** December 17, 2009, 09:05:40 PM »

Hey Guys...Thanks for all the advice so far. My plans have changed somewhat. Instead of a Trivial Pursuit I am going with the Vector 40 ARF I already have. I was initially disenchanted with this airplane because after I purchased it (from a friend of mine) I discover that some how the wing had been damaged and there were parts of ribs floating around inside the covering. I finally decided the way to get an airplane in the air as quickly as possible was to strip it down and fix the wing. Inside were about 25 pieces of ribs broken inside the C tube. After a couple of hours I have it all glued back together and it looks OK and appears strong. I'll strip the entire airplane, actually sand the tips of the stabs to round them off a little and recover it. My Hacker A30-10XL arrived today but I am thinking this might be a little too much motor for this smaller airplane. I would kind of like to put it in the Impact that I have about 50% built. Here is what I have in my "shopping cart" at RC Dude Hobbies for the Vector 40.

Scorpion 3020 890 KV V2 motor
Castle 50 Ice Lite
APC 12 X 6 E pusher
Hyperion GE 4S 2600 mah battery

Judging from what I have been reading this motor/controller combo should be good for this airplane. My question is is the battery large enough in capacity? Will that be enough to fly the pattern? It weighs about 9.6 oz. Is that to heavy? Should I go with a TP Prolite V2? I don't want to order to large a pack but I really don't want one to small. I realise I will be needing additional packs to fly with but just wondering what you think on the 2600 mil pack? Also is the Castle 50 Ice or the 50 Ice Lite the way to go?

Thanks,

Shawn

Dennis Adamisin · « **Reply #13 on:** December 17, 2009, 10:43:47 PM »

Shawn:
Alan Hahn converted a Vector last year, its in the "List your set-ups" thread. He had 2600 mah packs and found out they might be a little larger than what he needed - so I think you are OK

I have been using 2500 & 2600 packs in similar sized birds and they match up well.

Back to the Vector: check your prop clearance - I think others have reported 12" props are a little "snug" for the stock LG.

John Witt · « **Reply #14 on:** December 18, 2009, 07:42:23 AM »

Shawn,

Following Alan's lead, I built a Vector 40 from a kit, and love it. It's got about 20 flights so far, but I really like the way it flies. I did extend the stock aluminum gear legs by adding an aluminum strip the bolts on using the wheel pants mount hole with a 4-40 screw and the stock axle. The plane handles fine with the gear leg extension, lands and takes off from (short) grass very nicely.

See the specs in the Setup list. I'm using about 2050 mAh for a 340 second run, 65' radius, 5.2 second laps. Using a Zippy 2650 4S pack. Weighs 48 oz.

I cut out the LE of the wing back to the bellcrank tip to allow the battery to fit in and the balance has worked out to be very close to optimum. I think I will probably need to move the battery a little forward to get it just right. The nose is a tight fit for all the wiring, etc., but it does all go in there.

Good luck with the plane, it is a good flying bird.

John W

John Witt

Alan Hahn · « **Reply #15 on:** December 18, 2009, 08:05:05 AM »

a 4s2600 mAHr should be fine. I use a 4s2100.

Shawn Lenci · « **Reply #16 on:** December 18, 2009, 03:39:30 PM »

Alan and John...Do you guys think I should go with the Scorpion 3020 780Kv motor instead of the 890Kv on the Vector? I see both of you have used lower Kv motors than what I was looking at using. Would that be a better way to go?

Shawn

Alan Hahn · « **Reply #17 on:** December 18, 2009, 05:51:51 PM »

Quote from: Shawn Lenci on December 18, 2009, 03:39:30 PM

Alan and John...Do you guys think I should go with the Scorpion 3020 780Kv motor instead of the 890Kv on the Vector? I see both of you have used lower Kv motors than what I was looking at using. Would that be a better way to go?

Shawn

Shawn,
It all depends on whether you think you will want to fly with a flatter pitch/higher rpm setup than I use (like a lot of guys are doing). Right now I fly at ~8000 rpm on a 12-6 prop. I think I still have a fair amount of overhead on the battery voltage, but if I wanted to fly at ~9000+ rpm with a lower pitch prop, I might run out of voltage to keep that rpm.

If you have the 2600 mAHr packs, then it might be a bit "safer" to go with the 890 rather than the 780 kV motor. For me, it is a bit easier on the 2100 mAHr battery with the 780kV motor, since I am flying a little closer to 100% throttle. With the larger battery, a slightly lower efficiency is pretty negligible, so in your shoes, especially if you might want to try a lower pitch prop (I don't know), I might choose the 890.

John Witt · « **Reply #18 on:** December 18, 2009, 09:07:57 PM »

Yeah, what he says. Alan, as usual, has it right.

I've was flying with a cut-down 12-6, cut to 10.6 diameter so I could use the stock gear. With that prop the combo wants a higher RPM and a higher kV motor. If you use the bigger prop, lower kV motor. I'm headed that way now (may get to try tomorrow, supposed to not be raining) since my 750 kV motor is running out of overhead for the smaller prop. BTW, my Turnigy motor was spec to be 800 kV and turned out to be lower than the mfg. stated.

I have not yet tried the 13-4.5 pusher, probably cut to 12 inch diameter to start and about 8500 RPM.

The factors affecting battery used is shorter lines, slower speeds and lower rpm each reduce power consumption assuming you keep the line tension adequate. You'll get the hang of it.

John W

Dennis Adamisin · « **Reply #19 on:** December 19, 2009, 07:18:50 AM »

The 13x4.5 clipped to 12" turns at 10,400 to fly a Pathfinder on .018 x 65' lines at 5.4 sec/lap. I recently made some chagnes to the PF and will also move it to .015 x 63' lines. I have it set for 10k but have not been able to fly it yet. The smaller/lighter/cleaner Vector on .015 x 63' would require a little less RPM - maybe 9800 - 10k? I think this all adds up to needing the 890 kV motor with the 4.5 pitch.