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Old Apr 13, 2004, 12:21 PM
PDS
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Detroit Willow Run, Michigan, United States
Joined Sep 2002
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Graupner Piper Cub J-3 Conversion

Hobby Lobby has a Piper Cub J-3 that I would like to convert it to electric. http://www.hobby-lobby.com/pipercubj3.htm I know that E-Zone has an electric conversion with a Jeti 45-3 Brushless using 16 CP-2400 cells. This article was written in Feb of 2003. http://www.rcgroups.com/links/index.php?id=4066 My question is: With all the new technology, Thunder Power lipo’s and AXI outrunners, would there be a better setup for this Cub.
Graupner Cub Specs are as follows:
Wingspan: 72”
690 sq. in. wing area
Length: 40”
Weight: Hobby-Lobby states that the flying weight for gas is 6.5 lbs.
Radio: 4 channels: Ailerons, Elevator, Rudder, and Throttle

This will be my first conversion so I could us all your recommendations. I have been flying for a couple of years now and have flown indoor and out. Parkflyers and Zagi’s.

Thanks
PDS
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Old Apr 13, 2004, 01:55 PM
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jonnyjetprop's Avatar
USA, FL, Apopka
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Check in the scale model forums after ezone fixs the search function.

John
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Old Apr 13, 2004, 05:43 PM
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Well, it seems that you listed just BRUSHLESS motors and Li-POLYs so, you would need someone that has spent lots of $$$.

I have converted a .40 2-stroke SKY RAIDER MACH-I (65.5 inch wing span & 53 inch FUSE length) by World Models, an ARF using a KYOSHO ENDOPLASMA 16-Turn "BRUSH" motor and a used MEC MX-50 Brush ESC, Great Planes GD-600 gearbox with the optional 3.8:1 ratio pinion gear and using 8-cell, GP-3300mAH, Ni-MH. The model is supposed to weigh 5.5lbs assuming GAS but, my electric powered model tips the digital scale at 5lbs - 2 1/4oz. fully flight ready. Swinging the APC "E" 12 X 8 prop it draws 36.2AMPs & 330 WATTS total @ Wide Open Throttle.

The KYOSHO truck motor gives it lots of air speed and is able to perform all the neat tricks as that of a GAS powered model.

I have a co-worker that converted his SIG SENIOR KADET using the KYOSHO MAGNETIC MAYHEM 22-TURN Brush motor. Total weight of the model was 7 1/2 lbs. and it flew very well. I am sure an ENDOPLASMA would do great as well and with less cells.

Well, go spend the $$$$ and never mind these owful Brush motors...

Carlos
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Old Apr 13, 2004, 06:35 PM
Real Men Fly Pink Planes...
kepople's Avatar
United States, TX, Rockwall
Joined Jun 2001
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Quote:
Originally Posted by PDS
Hobby Lobby has a Piper Cub J-3 that I would like to convert it to electric. http://www.hobby-lobby.com/pipercubj3.htm I know that E-Zone has an electric conversion with a Jeti 45-3 Brushless using 16 CP-2400 cells. This article was written in Feb of 2003. http://www.rcgroups.com/links/index.php?id=4066 My question is: With all the new technology, Thunder Power lipo’s and AXI outrunners, would there be a better setup for this Cub.
Graupner Cub Specs are as follows:
Wingspan: 72”
690 sq. in. wing area
Length: 40”
Weight: Hobby-Lobby states that the flying weight for gas is 6.5 lbs.
Radio: 4 channels: Ailerons, Elevator, Rudder, and Throttle

This will be my first conversion so I could us all your recommendations. I have been flying for a couple of years now and have flown indoor and out. Parkflyers and Zagi’s.

Thanks
PDS
PDS, sent you a PM.

Kirby
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Old Apr 13, 2004, 08:19 PM
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Bill Sanford's Avatar
Bemidji, MN
Joined Dec 2003
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Quote:
Originally Posted by PDS
Hobby Lobby has a Piper Cub J-3 that I would like to convert it to electric. http://www.hobby-lobby.com/pipercubj3.htm I know that E-Zone has an electric conversion with a Jeti 45-3 Brushless using 16 CP-2400 cells. This article was written in Feb of 2003. http://www.rcgroups.com/links/index.php?id=4066 My question is: With all the new technology, Thunder Power lipo’s and AXI outrunners, would there be a better setup for this Cub.
Graupner Cub Specs are as follows:
Wingspan: 72”
690 sq. in. wing area
Length: 40”
Weight: Hobby-Lobby states that the flying weight for gas is 6.5 lbs.
Radio: 4 channels: Ailerons, Elevator, Rudder, and Throttle

This will be my first conversion so I could us all your recommendations. I have been flying for a couple of years now and have flown indoor and out. Parkflyers and Zagi’s.

Thanks
PDS
I'm in the process of converting a Kyosho Cub that has very similar specs.

I'm installing an AXI 4120/14 with a Phoenix 80 ESC and a 10 cell GP3300 pack. The Phoenix 80 is overkill because with a 14x10 prop the AXI on 10 cells should draw about 40 amps, giving me a little over 400 watts in. The finished model should weigh around 6 pounds.

It should fly the model very well.

Good luck with yours.

Bill Sanford
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Old Apr 14, 2004, 05:23 AM
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T_Hartigan's Avatar
Oak Harbor, Oh
Joined Jun 2001
663 Posts
Quote:
Originally Posted by PDS
Hobby Lobby has a Piper Cub J-3 that I would like to convert it to electric. http://www.hobby-lobby.com/pipercubj3.htm I know that E-Zone has an electric conversion with a Jeti 45-3 Brushless using 16 CP-2400 cells. This article was written in Feb of 2003. http://www.rcgroups.com/links/index.php?id=4066 My question is: With all the new technology, Thunder Power lipo’s and AXI outrunners, would there be a better setup for this Cub.
Graupner Cub Specs are as follows:
Wingspan: 72”
690 sq. in. wing area
Length: 40”
Weight: Hobby-Lobby states that the flying weight for gas is 6.5 lbs.
Radio: 4 channels: Ailerons, Elevator, Rudder, and Throttle

This will be my first conversion so I could us all your recommendations. I have been flying for a couple of years now and have flown indoor and out. Parkflyers and Zagi’s.

Thanks
PDS
What timing. I am looking at that very model to convert. It looks like a nice ARF.

I was looking at the AXI 4120 14 with 16 cells. Propped for about 500 watts.

After the search engine was running again, I was going to see if anyone had done a coversion using an endo setup.

The AXI looks like it would be a very clean installation without a gearbox. I've had the GP GD600 and it is hit and miss.

Tim
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Old Apr 14, 2004, 05:41 AM
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Here's one example of the KYOSHO MAGNETIC MAYHEM 22-Turn Brush 4X4 Truck Motor in the GD-600 Gearbox (by GREAT PLANES) with the optional 3.8:1 ratio pinion gear with set screw swinging the APC "E" 14X8 prop using the 12 Cells, GP-3300mAH SCHR's!

No hit and miss here?
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Old Apr 14, 2004, 05:43 AM
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The GP-3300 SCHR's (example shows 10 Cells only...)

Also, the MAGNETIC MAYHEM & GD-600 Gearbox and optional pinion gear!

Sure, a Brushless Motor will give you more efficiency but unless you buy a HACKER C40 or C50 that goes up to 90% efficiency then, you are only perhaps 8 - 10 % higher efficiency than these Brush Truck Motors.

I always say, lets keep the MODEL LIGHT and NOT YOUR WALLET!

Piper J3 should fly very nice and scale with this Truck Motor unless you like to make it a SUPER CUB or clip wing Cub then, in that case go brushless.

Carlos
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Old Apr 14, 2004, 05:56 AM
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A little write up on these Brush motors...
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Old Apr 14, 2004, 02:37 PM
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Oak Harbor, Oh
Joined Jun 2001
663 Posts
Quote:
Originally Posted by guapoman2000

No hit and miss here?
I'm not talking about the power. I'm talking about the quality and ease of setting the gear spacing. It also was rather noisy and easy to strip the spur gear.

I've used the gearbox with an endo and it has the power.

Tim
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Old Apr 26, 2004, 12:17 PM
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United States, MA, Webster
Joined Feb 2003
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Hi all .....

I just recieved the new Hobby Lobby catalog # 43. and on page 38 they are showing the Graupner 72" Cub with an AXI 412014 outrunner, aluminum motor mount, Jeti Advance 40 Amp ESC, 2-6 CELL cp-2400SCR battery packs (in series I presume), a prop shaft adaptor and APC (?) 13 X 8E thin electric prop. It is to be noted that it comes complete with fuel tank ... so I'm sure it's the same nitro powered airplane that's been around a while, just shiped with the electric power goodies. As I recall, in the review that was done on E-Zone (Fitz Walker maybe??), getting the battery packs in was accomplished through the firewall bulkhead, which would mean taking the prop and cowl off after every flight. It would be nice to put a hatch under the fuse, but the Cub style "double wire" landing gear might complicate that. AUW is 7.3 lbs. Just for reference, my 7 cell 2600 MaH Sanyo packs are just about exactly 1 lb. each.

OBTW, all the stuff, including a Hitec Flash 6 radio and a cheezy charger is $ 779.00 plus shipping.

I checked their website a minute ago, and this combo is not yet listed there, but it's in the catalog that came in the mail today.

Happy and SAFE flying,

Russ
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Old Apr 26, 2004, 04:15 PM
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Lititz,PA U.S.A.
Joined Nov 2001
57 Posts
J-3 Cub

Hey guys,
I just completed a Blackhorse J-3 Cub,same exact model as the Graupner just a different label. I'am using an AXI 4120/14,Jeti Advanced 70 amp OPTO speed control,14 CP-2400 cells and a APC 13 by 6.5 prop. All up wight is 118ozs. and it flys very well. Climbs are excellent and to date (6 flights so far) have gotten 6 1/2 min. flights out of her with millamps to spare.
For an ARF,I was very impressed with the quaility of the plane,great covering job too.
As for the brushed geared motor systems,they would fly it but there is something to be said for not having to change brushes every three months or so. If you can afford it,go with the AXI,you won't be sorry. Besides,if your in this hobby for the long haul,you'll get your money back in the sheer fun of flying them.
Geeee
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Old Apr 27, 2004, 09:13 AM
Visitor from Reality
United States, VA, Arlington
Joined Dec 1996
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Idle thoughts PDS

Ferrites work real well if you don't "wring them out" - keep within their limits and don't abuse them. Most decent brushless will run to their stated limits at least.

Cubs don't need a lot of power - that one in my avatar is Sig's 1/5th scale kit. 84.5" span - which is 'scale;, the 81" BARF Cubs are merely "IMAA legal". It flies fine on 16 cells at 8lb 2oz, could probably drop to 14 cells, but don't have the time to mess with fixing what ain't broke. I get around 15 mins of Cub-ish flight on 3000 mA nimh.

I charge its battery inside the Cub - access thanks to Sig's superb kit is through the scale cabin door and window. Are you happy either pulling a lipo out of the model to charge it, or charging it in place (do you fancy your model and motor going up in flames???)

Cubs all fly great!

If you want to be different without a lot of work, look up a yellow Cub and make up some "real" N numbers rather than the imaginary ones that come in the kit. Or look some more and find one of the J3's the USN bought early WW2 - basically yellow with military markings. Mine is a 'real' colour scheme, though I suspect it's not really a scale military scheme, rather it's how someone painted their Cub on restoration...

Good luck with her

Dereck
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Old Apr 27, 2004, 09:25 AM
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United States, MA, Webster
Joined Feb 2003
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Well .....

I found the page on the Hobby Lobby site with the "electrified" version of the Graupner slimer Cub. Either they just added it, or I wasn't looking hard enough the first time !?

This will be my "winter project" with skis and floats.

Link below:

http://www.hobby-lobby.com/j3cub.htm

Happy and SAFE flying,

Russ
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Old May 15, 2004, 06:37 AM
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glide's Avatar
Hawaii
Joined Apr 2003
554 Posts
Quote:
Originally Posted by geeee
Hey guys,
I just completed a Blackhorse J-3 Cub,same exact model as the Graupner just a different label. I'am using an AXI 4120/14,Jeti Advanced 70 amp OPTO speed control,14 CP-2400 cells and a APC 13 by 6.5 prop. All up wight is 118ozs. and it flys very well. Climbs are excellent and to date (6 flights so far) have gotten 6 1/2 min. flights out of her with millamps to spare.
For an ARF,I was very impressed with the quaility of the plane,great covering job too.
As for the brushed geared motor systems,they would fly it but there is something to be said for not having to change brushes every three months or so. If you can afford it,go with the AXI,you won't be sorry. Besides,if your in this hobby for the long haul,you'll get your money back in the sheer fun of flying them.
Geeee
Aloha Geeee. I just got the Blackhorse Models J-3 Cub in a couple weeks ago and I plan to do the same electric conversion as you did. I plan to use the AXI 4120/18 motor instead but other than that, my set up is basically the same.

Were you able to get the battery pack inside of the fuse to get the CG balanced or did you have cut the firewall out and have the battery sticking out like how they had it on ezone? Let me know how you got that worked out. Better yet, photos would be nice if all possible.

Aloha to all on RCGroups
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