World Models SuperCub

[capt wally]

Hi Guys/gals.

Keen 'plane' nut from 'down under" (OZ) just passing by here for the first time. Am curious if anyone in here could recomend an elect motor setup that would suit the new World Models 1/3 scale Piper PA18 Super Cub, The model weighs in around 29lbs (13 Kg's) as a fosil fuel burning monster:-)
Need to sneak over the neighbiurs place without him knowing, just kidding:-)

Regards

Capt Wally :-)

p.s.........& If i'm in the wrong forum here please be kind to an old Aussie:-)

[GordonTarling]

There's a build thread of the World Models 1/3 Clipped Wing Cub over on RC Universe in the 'Glow to Electric Conversions' forum. I feel that's probably a bit too much power for a standard Cub, but you can always use the throttle!

[AmpAce]

Hi, Capt Wally,

Welcome to the forum! I think you are in the right place, but don't know how much information you will get here. Even now, this big of an e-powered Cub is fairly rare.

That's a very interesting project you are contemplating, and I hope it works well for you.

That Super Cub should fly well on around 75 watts per pound, probably even substantially less, if you don't need leap-off-the-ground short field performance. With this in mind, you should be looking for something in the 2000 to 3000 watt range, at maximum power. The higher end of this range should give you great performance for a Super Cub.

I don't have any hands-on experience with anything close to that large, although I'm building a Balsa USA kit of a 1/3 scale Super Cub, but it will be gas powered.

If I were doing that project, I would try to find a belt drive, somewhere around the ratio of 2:1 or 3:1, working with a large brushless outrunner motor, that would allow me to turn a little larger prop. After all, a lot of working Super Cubs use 80 to 84 inch "climb" props, so you could go up to a 28 inch prop and still be scale. The larger prop should give you a little more efficiency in terms of thrust per watt.

Wish I could provide you with more specific information, but I just don't have a handle on specific applications for this size a bird.

Hope your conversion goes well, and that you keep us all posted on here! Who knows, I might even decide to electrify my big Super Cub if your project goes well.

Best of luck!

AmpAce

[capt wally]

Hey tnxs guys, AmpAce & Gordon you have been very helpful. this is a rather large project & I'm not an EP expert. Been flying models for ....well too long to want to recall but I like the idea of clean power with no mess.
AmpAce I did have 'till recently a Balsu USA`1/4 scale cub that I bought fully built & beautifully finished in authentic colours (spelt like an Aussie). That model had the OS Pegasus 320 flat 4 cyl, sounded great but the power was only just suitable, looked the part tho. Since sold the model, wish I still had it but the funds went elsewhere!:-).
Will probably put a Saito 300T in the Supercub at first but want to EP it some time down the track. Am keen to read what you guys over there on the other side of the planet have to say about all things electric. the super cub doesn't need super performance just enouhg to make it fly comfy at around half throttle. Anyway tnxs again guys:-)

Regards

Capt Wally :) p

p.s.............although this is a thread drift here in OZ most fly Mode 1, I fly Mode 2 mostly although can fly Mode 1, you lot over there seem to fly Mode 2 right?

[GordonTarling]

Capt. Wally - Ampace is pretty close in his estimation of power required - 3000 Watts should be plenty and is easily achievable with a large outrunner and a thick wallet! if you want specific recommendations, you only need to ask. I fly mode 2, but there are many who fly mode 1 here, too.

[R/C Dallas]

3kw doesn't have to be expensive. The high dollar item is going to be the batteries and they are coming down pretty fast. Just this weekend there was a vendor selling TP 5S 5000 batteries for $222 and another selling 6S 5000s for $225. That's the top of the line Extreme packs..not bad! Myself, I'm going the Dewalt/A123 route on a 3.5-4KW setup which ended up being right at $320 for 3 dewalt packs that will give me 14S2P and a 2-pack for receiver/servo duties. There are also some decent cheap motor/controller combos to be had that are quite capable of producing 3KW. I say forget the Saito and do it right from the start...E-power baby, yeah!

[capt wally]

Hey again tnxs guys, you guys sure do get excited about electrics :)
Ok so it sounds like I'll need 3KW of power with say 5S or 6S in the way of the cell count, obviously mah is duration. I am obliged to fit the Saito 300T first to the airframe as it's a review model to be configured how it would normally be looked upon by most modellers out there, but will change it to EP when i'm done.
Any specific suggestions as far as the outrunner motor goes guys?. Type/brand etc. & perhaps a speedy to suit. Am appreciative of all yr assistance over there:-) :)
Shall have a pix or two of teh completed bird in the near future on this site.

.............now better I go & make a living (flying) to help pay for the 'habbit' :)

Capt Wally

p.s...............I gathered that Mode 2 was more accepted over yr way guys, but obviously not so. Seems more natural to me esspecially when handling a chopper.

[GordonTarling]

Capt Wally - I'm afraid you've misunderstood slightly, 5S or 6S is not what you need. You should be looking at 10S or 12S packs. 3kW on 6S gives around 135 Amps - WAY too much. 3kW on 10S gives around 81 Amps - much better. 3kW on 12S gives around 68 Amps - even better!

[R/C Dallas]

I'm using a Hyperion Z5045-18B and a Jeti SPIN 99 which is on the expensive side. Here's one to consider if you don't mind buying from United hobbies. http://www.unitedhobbies.com/UNITEDHOBBIES/store/uh_viewItem.asp?idProduct=5141
You would probably have to go with a Castle Creations 85HV if you want to go 12S and keep the price down. United hobbies does sell a 90 amp ESC capable of 10S but as Gordon pointed out "12S (14S A123) gives around 68amps - even better!". Although you could swing a bigger prop on 10S (12S A123) Hmmm...I'd stick with the low amp setup myself.

[John Z]

That's one whopper of a motor! :eek: 6KW= 8HP. Enough to power a scooter.
For the price, it looks like quite a bargain. I wonder though about the longitivity of these cheapo Chinese motors.

[R/C Dallas]

The bearings are usually the weak spot on these cheaper motors. I have a TP 3520-7 that I' have been running for about two years without any issues. But I have heard of some folks having to replace the bearings after which they no longer have any issues.

The other issue with the china motors is effeciency is usually a bit down from the name brands. Usually around 10% or so which shouldn't be a problem in your application. You're not looking to push a motor to the edge to get extreme vertical fro your cub. And you'll have plenty of leeway when it come to battery weight as well.

The Hyperion Z5045 and Hacker A60 would be another good choice if you're uncomfortable with the other motors. Both have been used at levels over 4KW with no problems.

[capt wally]

Gee thanks a lot folks, the suggestions & ideas are coming thick & fast.
I guess none of us where born with such knowledge so it's a matter of learning from others, mistakes & all ! :)

Shall go 'shopping' for motors & speedy's as suggested here.

Again tnxs for the advice.

capt Wally :)