View Full Version : Carl Goldberg Kit built Cub conversion!!!
I have a Carl Goldberg kit #63 built up (not ARF). I also have both wings. 76.5" and 67.5". It was set up with a Saito 65 4 cycle. Flew great with either wing.
It's weight with that set up was 7lb 6oz.
I am in the process of converting to electric. Only I forgot to take a photo before I started!!!
I just weighed the Cub:
ready for batteries w/o wing=4lb 5.4 oz (including receiver bat)
Long wing=2lb 2.8oz
Clip wing=1lb 14.0oz
That put it at 6lb 8.3oz using the long wing
6lb 3.4oz using the clip wing
1lb of battery will put me 7lb 3.4oz or 7lb 8.3oz
I will be using the new E-flite 46 Outrunner.
JR Sport RS600 receiver
JR ST47BB servos
2 Thunder Power TP2650-4S2P 2650 mAh, 4 cells (14.8V) =15.52 oz total
It is already for the battery selection. And of course some better weather here in New England!
Weight ready to go without battery is 6 lb 8 oz
There is a thread on RC Groups about a CG Cub ARF kit. I have added some photos to that post as well.
I just wanted to try Wattflyer for my posts. Seems like there is a lot of help here on this site!!! (as well as on RC GROUPS )
10-05-2006, 11:39 AM
Did you ever finish the Carl Goldberg Cub?
I am building a Carl Goldberg Golden Anniversary Edition J3 Cub and I intend to try to convert it to electric.
I was going to try an AXI 2826-12 motor and wonder if it will be enough power to fly the Cub which has about a 76in wingspan at 7.5 lbs.
I also have an E-Flight Power 46 motor like yours and is supposed to be equal in power to a 46 size glow motor and would like to know if you had success with flying the Cub on it.
10-05-2006, 05:43 PM
I, too, have a 80% complete CG Cub that has languished as a Hanger Queen for a couple years. It has a brand new, un-ran O.S. FS-70S four stroke mounted, but have balked at any further investment in glow engine stuff.
It is a magnificent airplane, and if a conversion works well, I would love to keep it, sell the engine and go electric. I would only want scale-like performance and am not interested in drilling holes in the sky, so if anyone has good, working experience in converting it I would love to know the details.
There is a Senior Telemaster electric at Hobby-Lobby that has a 94" span, weighs 10 lbs, 8 oz and uses a 41 AXI motor and 16 NiMH cells. The glow version requires a .60 engine, so it must be in the CG Cub ballpark, performance wise. Li-po's would reduce the weight considerably. This is the thread (w/video): http://www.hobby-lobby.com/srtele-arf.htm
10-06-2006, 04:29 AM
I am also building a Great Planes 81" Cloth Covered Cub ARF and intend to fly it on an E-Flight Power 46 motor.
The reason I'm building these Cub's is that I had a 6ft Telemaster Electro ARF that I finally destroyed on the 110th flight. That is a 72" wingspan with an all up weight of 5 lb 6 oz with two 2100 3s LiPo batteries in parallel.
It was such a nice, large slow flyer that I just want to fly large slow planes now.
If you are considering a Telemaster you should try the Electro first since it is alread "e-flight" ready with the motor mount for an AXI 2826-12 motor and has a battery box with a simple battery hatch on the front top of the fuselage.
Now if I can figure how to put the 12 ft Telemaster in my Camry . . . . . . . .
10-06-2006, 04:53 AM
I have looked at that one (the 6' Tele). Is that the one with flaps? That would be interesting, but from what I hear the Tele series are about the last airplanes that need to slow down for landings! The GP Cub looks almost exactly in the same class as the CG Cub, but with a slightly bigger wingspan (I did mine in cloth, too, but from a kit).
Alas, I have a personal connection to this Cub, and would hate to see it go and would rather convert it. BUT, I am new to electro flight, and, frankly, some of the numbers are confusing... For example, the Senior Telemaster flies at over ten pounds, but uses as motor that is suggested for (I think) 6 1/2 lbs? And yet, some smaller Tele-class 'floaters' weigh less and seem to have bigger motors(?) So, I am still figuring that all out. I imagine that the CG Cub was designed for fuel (being a pretty stout little plane), so I don't want it to be a dog, but I don't need a clipped-wing aerobatics plane, either. (I think scale planes should fly like scale planes). You'll have to keep me abreast of issues or discoveries you make in building your Cub, if you would, and of course how it flies.
I believe the 12-foot Tele is even available in electric now. Yikes!
I do like the stability and scale-like aerodynamic behavior of the larger airplanes I have seen, though. I think there is something cool about reading 'Stick & Rudder' and being able to test it all out in a model plane, whereas the smaller planes don't behave the same way. Right now I am at the other end of the spectrum building a 1909 Antoinette that I believe a couple of tethered flies could power...
Thanks for the threads and info! I'm sure it will all congeal into some essential truth at some point and I will know what to use in the conversion with confidence : )
10-08-2006, 04:43 PM
Well, after having flown both the GP and CGb Cubs I only have to say I will never, ever buy another of these kits again. Not only do I find these planes to be overweight pigs, but the wood and cutting quality of either kit is of questionable quality as is the scale outline.
Both of these kits are designed for glow engines and the wood in the fuse and the wings is much too heavy. If anything I would take the lite? ply fuse sides from the Golberg kit and use it for a pattern to cut new sides from balsa and then add lightness.
I attempted to convert the GP Cub to electric using an Axi 4120/18 and only 16 cells with a 14X10 APCE prop. The comination of an already overweight airframe combined with the 16 GP-3300 SC cells made it nearly impossible to ROG as it tip stalled and flipped over on rotation. Now I have to rebuild the entire front of the plane including the firewall area because of the damage.
Whether or not I will continue with this plane remains a question as there are now better Cub kits such as Sigs 1/5 scale laser cut and Adria Page's 80" Super Cub, also laser cut, which can be fown with an Astro 05G and 12 cells.
I suppose that with what little there is left to reapir it could be back in the air . Would it be worth it? Maybe, but with the A.P. Super Cub which can be flown with smaller, lighter cells and motor why bother?
Just my 2c worth. jollyroger
10-08-2006, 08:46 PM
Yeah, the CG is pretty heavy, though also quite stout as if it was designed more as the clipped-wing, aerobatics version in mind. I know it is well over ten years old (I believe, as I got mine in '96) and I don't know if anyone was laser cutting in those days! And, to their credit they have always called it a 'stand off' scale.
But, at any rate, it might be a lost cause trying to electrify it. Pity.
But, that just means I WILL have to buy another Cub : )
10-10-2006, 02:15 AM
Which, as usual, all revolves down to two Cub kits at this size bracket.
If you want light weight, near-enough scale and can live with a Super Cub - Page Aviation's 80" is a cracker.
If you want a real scale J3, with superb kit engineering and a choice of regular or clipwing in the same box - with the correct rib spacing for both options - it's got to be the Sig 1/5th kit.
I had the Sig 1/5th in J3 - it was one of the best kits I've ever built (Adrian Page's 60" GeeBee R2 is the other) and, after years of kit reviews for mags, I've got some behind me. The structural engineering is superb, the laser cutting is incredibly accurate - more so when you consider the size of the thing - and the plans are equally superb.
I sold the J3 as big ain't really better - but it is a PITA to haul around. I love aeromodelling, but not enough to buy a furniture van sized model airplane shifter. Still, given a slightly larger vehicle, one day I may build another as a clipwing.
Even at 8.25lbs, and with 16 x 2000 ma NiMh cells, it floated around the sky at Cub-like speeds and flew "right off the board". It's only wierd habit was if I let it get too slow, it would continue to head where last pointed, but all the flight controls would stop doing their usual thing! I didn't do this much, but it was actually fairly 'safe' and slapping on some power sorted it out pronto.
In comparison, I once test-flew a GP Cub 40 - kit-built - on an AF25G and 16 x 2000SCR for a clubmate. It effectively only had one flight speed - b!@@&y fast - and was only really viable as a sports model because it was too nose-heavy to stall. Balanced correctly, it would have been an utter pig, as it basically landed at the same speed it flew at.
Am now building my third Cub, after a GP Electri-Cub and the Sig J3 - a Sig 1/6th clipwing. Now, you want to talk about a older kit that requires a little building effort. How's about there's nothing on where to put the RC gear, but it does describe both the CL and FF modifications :eek: .
OTOH, it'll be cute as a button and will fit into my little wagon without too much trauma !
BTW - am going for a record. None of my Cubs have been yellow!
PS - make that Four Cubs. I also had a No-Cal (16" span profile scale) rubber powered FF Super Cub. Flew great - what Randy Randolph design didn't - eventually, I gave it to a young lass at a model aircraft meeting. You don't meet many kids who are such fanatics about real model airplanes - her father was there too, he confided that he thought girls played with dolls and suchlike! At that, I had to push her along, so she went home with the Cub.
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