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NUTS
12-15-2005, 09:09 PM
Hey Brothers. Need some advice.
I have a Sig 1/6 scale Cub on the bench. Just about done with it other than installing my gear and motor. I was thinking of using a Hacker
A30-12L I already have. It is rated at 400W at around 25A. I would like to have good flite duration, so I was thinking about getting a TP 3cell 4200mah battery and a 40a esc. My AUW with this set up should be around 3 1/2 to 4 lbs. I have a watt meter so I can chose the right prop to put me around 25A, but I have not seen anyone who has done this conversion on any of the other rc sites. If anyone has done a high wing close to the Cub's specks. Your input would be most welcome.

Regards,
NUTS

OLD GUY
12-16-2005, 07:08 AM
Tried it 10 years ago! Astro cobalt 40 with 18 1200 nicads ! It was way too heavy & wouldn't get off the ground with all those big heavy batt.
It had flown well with Saito 45 gas!
Your's should be ok with the much lighter Gear
B.T.W. WATCH OUT for cub Stall when low & slow , mine stalled & crashed when i used ailerons on take off ,only use rudder till speed builds up!

OLD GUY

NUTS
12-16-2005, 01:09 PM
Thanks Old Guy,
Guess I will need to give my left thumb some practice. Do you recall the all up weight of your Cub ?

Regards,
NUTS

Dereck
12-16-2005, 04:36 PM
I just recently ran a piece in my mag column from a guy who converted a 1/6th clipwing with ten cells and a BL I can't honestly remember. He admitted that it wasn't done as an electric, so was a little hefty, but he loves flying it and says it behaves like it should in the air. IIRC, the weight was just under the upper limit of the glow kit's weight range

Assume you are doing the long winged J3, it should be not much heavier, have more wing area and thus give you a lower wing loading than a clipwing. Your 400W should be fine for this, especially if you hit your weight target. but I'd go for a larger prop diameter - Cubs don't go anywhere fast!

I built their 1/5th Cub - interesting point being that with all the radio in the kit locations and a MaxCim BL where the glow engine went, I had to get the batteries - 16 x 3300 NiMh - right up the front of the cockpit to get the CG right. Flew it with a 16 x 8 doing 7,000 RPM, which was somewhat overpowering.

With LiPo, you may have to put the batteries right up front, back of the firewall, or maybe even into the cowl area.

Never heard of a Sig kit that didn't fly well, glow or electrocuted. They are mostly electrics anyway, just they keep drawing the glow conversion on their plans ;) Good luck with your conversion, you''l enjoy flying her

Regards

Dereck

NUTS
12-16-2005, 04:54 PM
Thanks Dereck,
I have worked it out to were all of my gear will be as far forward as possible, other than the rx. I have left out the lower block of wood right behind the cowl to make a hatch for my battery. There is a lot of room between there and the fire wall, and if I have to I will cut out the lower part of the fire wall to slide the battery up if needed to get my CG right.
Also on another note I covered my Cub with Coverite Cub yellow fabric.
It is an iron on and is painted. It is the best stuff I have ever worked with. A little pricey, but well worth the scale look.

Regards,
NUTS

Dereck
12-16-2005, 10:32 PM
AAAARRRRGGGHHHH!!!!

Not another yellow one :)

If these shots work (have to go to a client's Christmas party - being self-employed is he!! on the peace and quiet front this time of year :eek: ) The little parkflier I'm hiding behind is my Sig 1/6th, the red, white and blue jobber is my GP E_Cub (present version) in a colour scheme lifted off a Florida based clip wing and the full size is one I always fancied.

I still might just buy Sig's 1/6th clipwing plan and put something that shape aft of 400W one day ...

But you just can't beat a Cub, whatever. You'll enjoy it no end

D

Dereck
12-16-2005, 10:48 PM
Yes, it's me again - I just went looking for the photo of what has to be the coolest clipwing Cub I've found, and the website has vanished. Moment's silence ... :(

About the 1/6th Sig kit - I've never had a poke around a kit box - what's the cowling made from? Moulded, block balsa, what? If I could do it without a plastic moulding, building off the plan would be a better deal for me - I only mutter about kit structures to where my wife gets fed up, and she can barely spell "aircraft". So, if I could just buy the plan and fill out the rest to my standards, we'll all be happier :)

On weight - if you want a challenge, I saw a guy at the 2005 King RC E-Vent down in NC with a Sig Kadet Seniorita that weighed 39oz RTF - and had enough power and control to do knife edge passes the length of the field. With one wingtip about four feet off the ground ... :O On the outside, it was the same size and shape as a 'rita and even had the trike gear.

Another tip, but this one might not do it for you. It's not that hard to build a working UC to the same principles and close to scale for any Cub. THere used to be a great model Cub slanted website around with details of scale gear for the Cub, but it appears to have disappeared. You only need mod the fuselage pick-ups at most, and use wire and K&S brass tubing for the gear, plus O rings for the "springs". The one gripe with my 1/6th was that the rigid wire gear was tricky to set down on nicely on tarmac, though it wasn't as bad on grass, if I'd have kept her, she'd have got a sprung gear eventually.

I've flown a similar sized high winger to a 1/6th Cub with a sprung main gear and it was a lot nicer than a rigid MW gear.

Now look what you gone and made me do - I want another Cub!

Wonder if I finished off my Astro /SOY Porterfield as a clipwing ...?

Regards

Dereck

NUTS
12-21-2005, 02:23 AM
Hey Dereck,

Sorry it took so long to reply, took the wife and kids down to see Micky Mouse for a few days.
I love the red white and blue Cub. Bet it looks great in the air.
I wire and soldered the landing gear together today, it fits well, but I just don't like it. I have seen an ad in the AMA mag. for a 1/4 scale and a 1/5 scale, but not for the 1/6 scale. Even if they did have the 1/6 scale they want $100 for the other two Sure would like to find an affordable sprung gear for it.
If I had a plan of one I could build I would try it. I'm sure it would look and perform better than the one that it came with.
As for the "Not Another Yellow Cub" comment. I just had to. This is the first real scale kit I have done, and the guy who owns the hobby shop and feild that I fly at has a full scale one that he fly's, "great for getting the details right".
Let me know if you know where I can get the LG or a simple plan for one.

Best Regards,
NUTS
P.S. The cowl is molded fiberglass

Dereck
12-21-2005, 03:09 AM
Hi Nuts
(I never could get the hang of this cute screeen name business :) )

If intensive googling doesn't turn up a Cub UC, here's a link with a Cub plan on it, but somewhat fuzzy and I think the mag is dead:

http://www.yolo.net/~jeaton/gems/6cub.htm

What I think it shows, and better than I can describe it, is a lighter wire UC with rubber band springing where the real Cub had its springs. I had a large scale model of a Bonner "Smog Hog" (9/14th full size, definitely IMAA legal - Bonner's was 74", mine was 53" or so ;) ) with a similar gear and it was nowhere near as bouncy as a plain wire gear.

Gordon Whitehead, who sometimes hangs out in the scale forum, has done a fair number of designs with sprung gear of various prototypes - his latest was a lovely Tiger Moth that was published in the late RCM mag, with full details of its UC. Wouldn't be hard to adapt that to a Cub format, and it's made mostly of brass tube from K&S - which most LHS and many craft shops carry - some wire and small bolts/nuts.

If all else fails - that one from England had nothing more exotic than the kit gear, nicely togged out as 'scale' and a pair of "Trexler" airwheels, which are still in production and pretty easy to get. Okay, you have to pump the beggars up, but they give a far better ride than sponge rubber tyres and don't look too bad on a Cub either.

I'm all for keeping sports models simple - even scale-ish ones!

D

NUTS
12-23-2005, 01:58 PM
Broke down and bought me a wire bending tool. Got some new wire and fabricated my own "sprung" landing gear. Looks like it will work much better than the one the kit came with. I am seriously thinking about the Trexler tires, it would look sporty.

Best Regards,
NUTS

Dereck
12-29-2005, 09:13 PM
The biggest pain with Trexlers is blowing them up - the Trexler inflator is pricey and not that good. I have a huge syringe I got from Andy Clancy back when he was peddling his own stuff. It must be 600 cc's or thereabouts, but does a great job. The hubs are turned wood, but work well enough as long as the wire's a good fit.

Cool factor amongst real aeromodellers is high, though they will baffle the instant gratification lot somewhat :rolleyes:

Once you've bought the wire bender tool, wire UCs are pretty cheap and work well. If you ever need to practice, soft wire coathangers from dry cleaners are good to practice on - the Chinese BARF industry use them for UC legs, so they can't be all that bad ;)

D

NUTS
02-02-2006, 08:16 PM
Sorry I have been away for a while, but just wanted to let you know that we maidened the Cub yesterday. I took it over to Hodges Hobbies in Andersonville, Ga. "If you haven't been there you are missing out" and let Mac take it up for me. Yes I was a little nervous about it being that it was my first real scale project and did'nt want to muck it up. Mac applied what looked like to be around just over 1/2 throttle and in 50' she was up, and I do mean up. Not very scale, but as they say you can always throttle back . Mac had to do very little trimming. He flew it around for a few then turned the controles over to me. I need to program some rudder in with the ailrons to keep the tail from dropping but other than that it flew great. Bill Davenport flew it for a while too with no complaints.
I gave the controls back over to Mac who made a few touch and goes, and finally in for a landing. Suprisingly no bad habbits on ground handling.
Here are the specs:
With a Hacker A30-12L and a Thunder Power 4200mah 3cell Li Po
the AUW was 4.7 lbs
An APC 11x5.5 elec. prop at 3/4 throttle pulled around 28amps just over
300w. It is capible of quite a bit more but the Cub does not need it.
Looks like around 60 to 65 watts per pound.
Would like to send some pic's but I can not size them properly to get within the guidelines of what Wattflyer requires. I will keep working on it .

Regards,
NUTS

NUTS
02-02-2006, 08:39 PM
Here Are Some Pic's, I Hope

Dereck
02-02-2006, 09:09 PM
Hi Nuts
That sure is pretty and YELLOW!

Always said Sig make the best electric model kits around, shame they keep drawing glowburners on the plan. MIght have to find time to build one of these - a Cub is real nice to have around, but the big one I had was a pain to haul around.

Good luck flying her - if I get down that end of the world, will be keeping an eye out for her. There's a model magazine column I know real well that would look all the better for some shots of your little bear ;)

Regards

Dereck

badbill
02-10-2006, 01:21 AM
Steve,
Thanks for allowing me a bit of stick time on the Cub. You did a great job on it and it showed in how well it flies. I enjoyed it!

Bill Davenport
AMA 28141

"If some is good, and more is better, then too much is just right"

NUTS
02-10-2006, 01:29 PM
Hey Bill,

Good to see you here. More thanks go to you for your advise on the build.
It would not have as succsessful if it were not for you and Mac.
Looks a little too breezy for this weekend to fly, but if I can get away I'll make the trip over to Mac's, "I HAVE SOMETHING NEW TO SHOW YOU".
Yes the Texan fly's again!

Regards,
Steve

Dereck
02-10-2006, 06:57 PM
After seeing that 39oz Electric Seniorita, and fondly recalling my 1/5th Cub, I still might have to buy the cowl and plan sometime. 4S2P Saphions and an AXI 2620 with a big prop on a lightweight framed clipwing would be kinda fun.

Let's face it, a Cub is one of history's rare aircraft - one that could only be replaced by another one just like it.

D

NUTS
02-14-2006, 09:58 PM
Hi Nuts
That sure is pretty and YELLOW!

Always said Sig make the best electric model kits around, shame they keep drawing glowburners on the plan. MIght have to find time to build one of these - a Cub is real nice to have around, but the big one I had was a pain to haul around.

Good luck flying her - if I get down that end of the world, will be keeping an eye out for her. There's a model magazine column I know real well that would look all the better for some shots of your little bear ;)

Regards

Dereck

Hi Dereck

Let me know if you would like any other pic's of the Cub. If you would like to use them in one of your columns I would be honored, annonomously or not. It has been a real joy to do a gas to electric conversion that to my knowledge not many have done. And for it to perform as well as it does really makes me feel good about my limited skill. "Only building and flying for 3 years".
Thanks for your advice in the thread.

Steve Breland
AKA NUTS

jonnyjetprop
02-15-2006, 01:23 PM
I know that's not a Sig kit, but how about the Page 80" Super Cub.

http://www.adrianpage.com/supercub80.html

John

NUTS
02-15-2006, 01:58 PM
Hey John,

That Cub looks GREAT! I like the looks of the frame work "looks real sturdy". A little more $$$ than the Sig kit. I only paid $74.00 for mine.
Let's electrocute another one.

Regards,
Nuts

Dereck
02-16-2006, 04:29 AM
I know that's not a Sig kit, but how about the Page 80" Super Cub.

http://www.adrianpage.com/supercub80.html

John

Fantastic kit, about as close to true electric as an 80" Cub is going to get. Adrian's kits are really good, light and well engineered. If you can haul an 80" wing around, you'd have a superb model. I had 16 cells at around 28A into my MaxCim powered Sig 84" at 8lb - Adrian's S-Cub will come out nearly two pounds lighter.

Still pondering on another smaller baby bear ...

D

Twmaster
02-17-2006, 02:13 AM
How many watts to fly the 1/6 Cub? A local club is having a scale meet in June and I want to get a big E-power plane ready for this event. Powering it is my only question. How many watts is the answer I seek.

Dereck
02-17-2006, 03:17 AM
My 84" 1/5th scale Sig Cub at 8lb and a little bit started on 20 cells and behaved more like an UltiEdgExtra pattern ship. I took them out, put in 16 without re-propping and it became close to managable, though still overpowered! I never did figure out how to get my Wattmeter in there, but a rough guesstimate suggested that on 16 jugs, she was only pulling 25 - 28A flat out. The Page 80" Super Cub is a lot lighter and could probably act Cub-like on 14, maybe even 12 cells - 4S in flatpack - and I saw a Kadet Seniorita fly down in NC last year at 39oz. It was capable of holding a level knife-edge on a 2S lipo at maybe 25A flat out. As the baby Bear is about the same size and bulk as a 'Rita, it would be possible to prop up the 1/6th Cub cowl and put a real light structure aft of it and come out with a really light, scale-like flier even at smaller sizes.

Of course, how a small, quiet model would be judged in a day when the 1/3rd scale hovering Cub would be lauded by all is another matter... ;)

This is all starting to get me interested in Cub-ing again...

D

Twmaster
02-17-2006, 03:55 AM
OK, so realistically we are talking about 400-500W of power. I'm not interested in going through a bunch of hoops to make the plane super light. H-L has a 72" Cub that they claim flies well on an AXi 4120/14 which is nearly identical in power to the E-Flite Power 46 outrunner. So perhaps that will be a good choice to get the bear moving in a scale like manner.

Dancing bears belong in the circus. Not the airfield. :D

NUTS
02-17-2006, 01:31 PM
Hey Mike
Welcome to the thread.
The Cub that HL is selling seems to me to be a little piggy for it's size "over 7lbs". I don't know if you have the time to get a kit together, but if you did that would be the way to go. I think all Cub's act pretty much the same, a 4 lbs Cub flies well at 50 to 65 watts per pound, so will a 7 lbs Cub. The HL would require 350 to 400 watts to fly scale. This would also give you enough power to get out of trouble if you need to. My Sig Cub 71" wing span performes great at less than 1/2 throttle.
I like the quote that Bill Davenport uses in thread #13. He is the guy who helped me with my motor and battery selection.
Good luck, and let us know how it goes.

Best Regards,
NUTS

TeamTEOR
09-20-2006, 08:42 AM
Yes, it is a old thread, hope you guys don't mind someone bringing it back. I have a Hangar9 80 inch Cub sitting in its box still.... Actually, the only thing done was to put the wing together and the aileron servos are in place but not screwed down. I have a brand new OS .46FX in the box, but I don't want the clean up & problems of the gas anymore. I am spoiled with the clean reusable electric stuff. Since this thread has been sleeping a lot of cheaper motors have been introduced into the market. I would like to explore those options, some kind of outrunner and a 4s pack. I have quite a number of ESCs ranging from 100 amps down to 40. Does anyone have any ideas from the newwer cheaper stuff that is out? It will fly with a Futaba 8ch RX, standard size futaba servos, and a 9C super radio.
Thanks in advance.
Tom

NUTS
09-20-2006, 01:59 PM
Hey Tom IMHO it's an oldie but a goodie. What is the AUW of the Hangar 9 Cub?

Regards,
Nuts

Dereck
09-20-2006, 03:22 PM
My Sig 1/5th J3 - 84.5" span, 8lbs and a bit - was powered just fine on 16 x 3000mA NiMh and a MaxCim 13Y swinging a 16 x 8 APC-E at trivial amps, maybe 25 - 30A, some 6,000 RPM. This selection was made so technically too - 16" is about a scale Cub sized prop!

With all that care in selection - I still can't recall the gear ratio - it was off the deck in some 15 feet and climbing far too non-Cub-ishly.

About anything that will do that kind of prop will suffice for Cub-like flying. There's been a couple of succesful ones at this sort of size on two Magnetic Mayhems geared onto a central driveshaft (I just happen to have a pair of un-run MMs on a UK made gearbox, if you want a real cheap solution!).

Outrunner - something from AXI that starts with a 4 ?

Of course, if you have to hover it ...:eek:

C140
10-04-2009, 09:54 PM
Looks like it's been a few years, but I guess I'll post anyhow. I've got a 3548-09 outrunner from Heads Up RC that's supposed to put out 330 watts on a scale sized (72"/6=12") prop. Is the Sig 1/6 scale Cub a good match for this motor? On the Sig website it says .25 to .40 glow, but I don't want to have unlimited vertical, I just want it to fly the way it's supposed to.

Dereck
10-05-2009, 01:47 AM
Funny you should mention that one...

I sold the 1/5th as 'bigger ain't better, but it sure is a pain to haul around' - and shortly afterwards, replaced it with a Sig 1/6th clipwing.

Which isn't yellow either.

Your 330W motor should do fine. My 1/6th has a Mega 45-something-something inrunner that swings around a 12" prop on 3S Lipo and flies the model fine, if not in clipwing style as well as 4S. In a regular wingspan, should work fine for your Cub-like flying aims.

I suppose as a long time e-flier, I should be able to quote wattage, amperage and voltage to two decimal places, but I never really got the hang of that stuff ;)

Hope that helps

Dereck

kyleservicetech
10-05-2009, 02:45 AM
Hey Brothers. Need some advice.
I have a Sig 1/6 scale Cub on the bench. Just about done with it other than installing my gear and motor. I was thinking of using a Hacker
A30-12L I already have. It is rated at 400W at around 25A. I would like to have good flite duration, so I was thinking about getting a TP 3cell 4200mah battery and a 40a esc. My AUW with this set up should be around 3 1/2 to 4 lbs. I have a watt meter so I can chose the right prop to put me around 25A, but I have not seen anyone who has done this conversion on any of the other rc sites. If anyone has done a high wing close to the Cub's specks. Your input would be most welcome.

Regards,
NUTS

Brings back memories of a 1/4 scale Piper Cub I built in 2000. Power was an Astroflight Geared 90 with 20X10 prop, turning at about 6000 RPM. Weight was some 17 pounds with 38 RC2400 Nicad cells. Both gearbox and brush type ESC were scratch built. The ESC was my design. Flew very nice, and finally sold it in 2005 after countless flights on it. Ten minute flights were normal, even with Nicad cells and a brush type motor.

And, you absolutely had to turn it with both ailerons and rudder!

Dereck
10-05-2009, 03:12 AM
I cranked in around 30% differential on my 1/5th and found it only needed co-ordinated rudder/ail at very low speeds. Normal cruise, it turned fine on ailerons only.

It's real oddity was discovered one day, on finals to land. It got real slow, we're all watching it as it was doing fine and it definitely wasn't messing around near the stall, when I felt a need to waggle something.

It did nothing :eek:

Fast application of power, up to '3 mistakes high' and some try-outs. Turned out the model would slow up to where it was flying, wings level and not stalling, but would not respond to any but really violent control inputs. Very wierd! With the right wind, I could do upwind field long ambles at real Cub-like scale speeds, as long as I got it pointing the right way first. THe way out involved just some extra power.

38 nicads - that was a serious model indeed. Most I ever got to was 20, in the dear old Four Star, pre-wing clipping.

D

kyleservicetech
10-05-2009, 05:13 AM
I cranked in around 30% differential on my 1/5th and found it only needed co-ordinated rudder/ail at very low speeds. Normal cruise, it turned fine on ailerons only.


Fast application of power, up to '3 mistakes high' and some try-outs. Turned out the model would slow up to where it was flying, wings level and not stalling, but would not respond to any but really violent control inputs. Very wierd!

38 nicads - that was a serious model indeed. Most I ever got to was 20, in the dear old Four Star, pre-wing clipping.

D

"Very wierd", Interesting, my 1/4 scale Piper Cub did exactly the same thing at very low flying speeds.

Also had a Four Star, ran it with a geared Astro 40, with 22 RC2400 Nicad cells. Still got it, might some day put in some A123 cells and one of my Hacker motors. Maybe sometime.

Dereck
10-05-2009, 08:30 PM
The first time I saw a 'real' Cub take off was in England, back around late 1980s. Not like I hadn't seen plenty of real slow old aircraft fly before, but Cubs are not plentiful over there. My impression was that take off mostly happened because the earth's curved and eventually dropped away from the Cub's wheels...

Okay, the likes of a Tiger Moth don't exactly blaze across the skies, but that Cub impressed on me how slow they go while committing aviation. Unless you're brave enough to translate Pat Trittle or Flying Aces type structures into quarter scale, any Cub model looks like it's tearing the skies open.

We'll ignore the star of a local big club I once saw hovering a gas powered big Cub model.

My dear old Four Star is presently hanging from the 'Ceiling of Fame' (Like a Hall of Fame, but differently laid out ;) ). It's still airworthy, but looks a little time-worn due to that the wing section and main framework is all that hasn't been 'got at' at some time or other. If you need impetus, it's all time best performance was on a 15 x 10 APCE that turned at 7,000RPM off a fresh charged pack (16 x 3000mA Sanyo NiMh) - call it 650W to be cautious. That was the pinnacle of a lot of flight testing.

If I could have sourced a replacement pack after mine died, I might have kept the Hacker B50/6.7:1 gearbox and just kept flying her on NiMh. They were so much less fuss than LiPo, but lack the marketing efforts :rolleyes:

Regards

Dereck

C140
10-05-2009, 11:36 PM
Thanks for the reply Dereck. The description of the Cub take-off is great and that's what I'm after. We were standing outside a hangar the other day when a guy made a pass up the field in one. It seems like the whole plane is always in slow motion. I've just got a few more questions.

Does the 1/6 scale one have real ailerons (of the non-strip variety)?
How hard is it to get the struts on and off for transport?
Does the stock cowl have cylinder heads?
How hard would it be to frame in a door into the fuse? I love seeing them fly with the door open.

Dereck
10-06-2009, 03:06 AM
Does the 1/6 scale one have real ailerons (of the non-strip variety)?

Yes, they are, as far as I can tell without measuring, pretty close to scale. THe underside pushrod is about in the right position too.

How hard is it to get the struts on and off for transport?

One bolt on the strut / fuselage end, four bolts a side for the strut ends. I leave my struts on the wing for transport - it will come off by unbolting the struts from the fus and unbolting the wing, jiggling it off to get the strut ends clear. Not sure but I have vague memory of replacing wood screws with bolts/T nuts for the strut end fixings - screws would wear too quickly if removed/replaced much.

Does the stock cowl have cylinder heads?

Big NO there - and the Great Planes 20 sized Cub dummy heads don't really cut it either - bought some with intent to fit them. I built/flew the model as per the kit as it was being reviewed for a paper mag out in RealWorld.

How hard would it be to frame in a door into the fuse? I love seeing them fly with the door open.

It's part of the kit, IIRC. Mine has the lower door hinged with a magnet to hold it shut. I don't bother with the top half window at all.

"Anything remotely scale takes far, far longer than a sports model" - old aeromodelling saying. Ten years to build a scale model is a span I've heard of from the builder's mouth! Mind you, it was a humungous P38, around 100" span. He said the problem was mostly that he'd get something made, to find out technology had marched on and he could now buy a much better widget to do the job with...

Regards

Dereck

C140
10-06-2009, 05:36 AM
Thanks again for the info. I don't want to spend too much time making it scale, but I want it to look right, and I heard somewhere that Fiberglass Specialties sells a cowl with heads and a PA-11 style full cowl for this kit, so I might look into that. I'd kind of like to try out that Coverite fabric too, but I'm getting ahead of my self. Funny, I worked out what the scale power loading would be. 39 watts per pound is equivalent to the original 65-horse Contenintal if I did my math right. With 330 watts, I'm close to a 150 hp J-3. ::o

kyleservicetech
10-06-2009, 06:01 AM
Thanks again for the info. I don't want to spend too much time making it scale, but I want it to look right, and I heard somewhere that Fiberglass Specialties sells a cowl with heads and a PA-11 style full cowl for this kit, so I might look into that. I'd kind of like to try out that Coverite fabric too, but I'm getting ahead of my self. Funny, I worked out what the scale power loading would be. 39 watts per pound is equivalent to the original 65-horse Contenintal if I did my math right. With 330 watts, I'm close to a 150 hp J-3. ::o

Trust me, 39 watts per pound for an electric model would be very underpowered. Scale effect or something. You might have to hand launch it. Double that or more to make certain you've got enough horses in the nose. You can always reduce power once the model is off the ground.

Dereck
10-06-2009, 10:03 PM
Definitely agree on the power needs too - 39WPP is going to produce mostly a fast taxy around.

It's all kind of long winded, but Dave Platt, who knows the odd bit about scale flying, once published thoughts on power and scale models and made a lot of sense in that to fly scale-like you actually need to have a fair surplus of power.

IIRC, the basic loop illustrates this well. If you don't have some spare power, to loop, you power up, let the model accelerate and then enter the loop. With that spare power, you can pull up from regular cruise speed, apply more power and let that pull the slowly travelling model up to the top. It applies that old aviating principle of having a little too much - height, runway ahead of you, spare fuel - is better than having too little.

It does demand that the pilot works real hard at the throttle setting, to match up scale appearance in speed during all elements of flight. Flying scale comps is the most demanding demonstration of that.

The other end is the 'sports flier' who treat the throttle as an on/off switch - they've surely pervaded e-flight by now ;)

I'd be looking at 80WPP in a Cub-ish model, maybe snukking in 100WPP in a clipwing Cub, just in case.

On cowling matters, being talent-challenged in the arena of creating dummy jugs, I suspect a shift to Super Cub variants is in my future Cub-ish fleet :)

Try this one for colour:
http://www.google.com/imgres?imgurl=http://wiki.classicflyersnz.com/images/thumb/a/a4/PiperSuperCub-01.jpg/400px-PiperSuperCub-01.jpg&imgrefurl=http://wiki.classicflyersnz.com/index.php/Piper_PA18A_Super_Cub&h=300&w=400&sz=42&tbnid=xxtWISspI26YfM:&tbnh=93&tbnw=124&prev=/images%3Fq%3Dpiper%2Bsuper%2Bcub&usg=__PkhKWyLLfawySN0rXb5EI1ban3w=&ei=ZLDLSqbOB86mlAfe4NnJBQ&sa=X&oi=image_result&resnum=4&ct=image

Regards

Dereck

kyleservicetech
10-06-2009, 10:53 PM
Definitely agree on the power needs too - 39WPP is going to produce mostly a fast taxy around.

Dereck

One nice thing about electrics versus glow/gas power, is that electric motors are kind of a "Constant RPM" power source. Putting a much smaller prop on an electric motor will simply reduce power output at pretty much the same RPM. At least, as compared to doing this on a glow engine, would result in the engine running at far to fast of an RPM.

So, build your model with some 100 watts per pound of weight. Then if you really want to reduce power, simply put on a smaller propeller.

C140
10-08-2009, 06:04 AM
That's my plan. The motor is capable of well over 400 watts, but I'm propping back to scale diameter. If I don't like it, I can try some different sizes. Another thought is that 150 hp puts me about the right size for a Super Cub. The airframes are nearly identical except for a slight increase in tail surface area and flaps. It might not be too hard of a conversion. Anyway, I don't think I'll start rolling on this project until after Thanksgiving, so I've got some time to figure out what I want to do. Thanks again for your help guys.

kyleservicetech
10-08-2009, 06:07 PM
That's my plan. The motor is capable of well over 400 watts, but I'm propping back to scale diameter. If I don't like it, I can try some different sizes. Another thought is that 150 hp puts me about the right size for a Super Cub. The airframes are nearly identical except for a slight increase in tail surface area and flaps. It might not be too hard of a conversion. Anyway, I don't think I'll start rolling on this project until after Thanksgiving, so I've got some time to figure out what I want to do. Thanks again for your help guys.

I put a Hacker A50-16S motor with 6S2P A123 cells, and a 16X12 APC-E prop on a Showtime 50. That motor turns the prop at 5900 RPM, and results in a take off run of about 30 feet on a 7 1/2 pound model.

Nice thing about this is, slowing down the motor to about 3/4 throttle or so allows flights of 9 minutes, using about 3/4 of the battery.

So, a nice large diameter "scale" sized prop, and a motor with a fairly low "KV" rating that turns a large diameter prop would be just perfect with your cub.

I've seen many other motor brands at our club, but you still can't beat the Hacker class motors for power, efficiency and reliability.

If you've not used it yet, check out www.motocalc.com (http://www.motocalc.com) for good info in setting up your model. That program is free for the first 30 days.