Reinforcing SuperCub

[CaptainMalick98]

Hi, i bought my dad a super cub a few years ago for his birthday, but he's since developed hand problems and hasn't been able to fly for the past 3 or so years, so hes giving me the plane. Sitting in the garage destroyed the rubber bands, and the wing struts are way too lose, and the landing gear broken. I made myself some better landing gear using a 6013 mild steel welding rod and 2 4 inch wheels for good movement over terrain. I've gotten the engine and servos up and running, but the struts and rubber band still need attention. I would like to go flying Sunday, so i don't want o have to wait for parts to arrive, so is it okay if i use #64 rubber bands? I've read on the forums that some use them but i just want to make sure. As for the struts, could i fly without them? If i need reinforcement, would using a few foot-long BBQ wooden skewers in the wings (i don't have CF rods) do the trick? Their quite strong and stiff, but still have a little bit of leeway for wing flex.

Thanks!

[JetPlaneFlyer]

on the landing gear.. mild steel is no good. It's too soft and will bend on landing. if you make it thick enough to have enough strength then it will be too heavy.
You should use piano/music wire. This type of wire is strain hardened and works like a spring on landing, bending to absorb the impact but springing back into place.

As for rubber bans. Dont use anything much thicker than it came with as they might damage the plane. Smaller is ok, just use more bands, it's not an exact science, just use what feels right.

I don't have the Cub so I'll let others respond to the strut question though i suspect that they are functional, so you should not fly without them.

I'd also guess that if it's been sitting for three years the batteries will be shot.

[solentlife]

Originally Posted by CaptainMalick98

Hi, i bought my dad a super cub a few years ago for his birthday, but he's since developed hand problems and hasn't been able to fly for the past 3 or so years, so hes giving me the plane. Sitting in the garage destroyed the rubber bands, and the wing struts are way too lose, and the landing gear broken.

Ok - no surprise if left so long !

I made myself some better landing gear using a 6013 mild steel welding rod

Forget it - heavy and as JPF says - unsuitable material. Better to visit LHs and either buy Piano wire or alloy sheet undercarraige ...

and 2 4 inch wheels for good movement over terrain.

Ok ..

I've gotten the engine and servos up and running,

Good ...

but the struts and rubber band still need attention. I would like to go flying Sunday, so i don't want o have to wait for parts to arrive, so is it okay if i use #64 rubber bands? I've read on the forums that some use them but i just want to make sure. As for the struts, could i fly without them?'

as JPF says - if you juse smaller - just use more !! and remember that you need more than just a couple of bands .. I use 6 to 8 depending on model.
second do not fly without the struts - foam models of this kinbd will not thank you if you leave those of - they provide serious support mostly stopping wing from folding UPWARDS in manouevres

If i need reinforcement, would using a few foot-long BBQ wooden skewers in the wings (i don't have CF rods) do the trick? Their quite strong and stiff, but still have a little bit of leeway for wing flex.

Better to use the BBQ skewers along the struts ... I do that with my Cessna 182 ... the struts break and I am loathe to go and buy another set of plastic struts - so I lay BBQ skewer along the strut ... Superglue run along the joint ... then suitable colour tape over to help keep two together and cosmetically blend into model ... never failed !


Nigel

[gramps2161]

Strut problems with the SC is common I switched my deceased cub to using spider wire fishing line.
Here is a link to a thread with some pic's not my plane, but it will show you the setup.
http://www.wattflyer.com/forums/show...t=47169&page=3

[solentlife]

Originally Posted by gramps2161

Strut problems with the SC is common I switched my deceased cub to using spider wire fishing line.
Here is a link to a thread with some pic's not my plane, but it will show you the setup.
http://www.wattflyer.com/forums/show...t=47169&page=3

Another way is to use the long electrical ties ... the tails are actually quite good for this in the big long size. Cut of the locking box end .... you can even drill the ends and use the original screws on some models as the plastic is flexible enough to bend for the screw.

As we get older - we find more and more uses for the scrap we hoard !

Nigel

[CaptainMalick98]

Alright thanks for the advice. I'm gonna buy fishing line as the struts are overstretched and i don't like them. I can't even put them on because they're so long they fall off even when the plane is upside down. For the landing gear, i this material because i could bend it easily. I will be buying music wire, but what diameter yo you suggest? My welding rods are 1/16th, and it fits well in the slot. Do you guys think that 1/16th music wire will be strong enough? Also, how do i bend it? Do i need to heat it? Thanks

[JetPlaneFlyer]

The fact that the welding rods are very easy to bend tells you something about what might happen when you put any stress on them

I'd guess you should be looking at about 2mm music wire. You bend it cold, don't use any significant heat otherwise you will anneal it and make it as soft as mild steel.

[solentlife]

Originally Posted by CaptainMalick98

Alright thanks for the advice. I'm gonna buy fishing line as the struts are overstretched and i don't like them. I can't even put them on because they're so long they fall off even when the plane is upside down.

??? that sounds strange ... are they not fixed in any way ?

For the landing gear, i this material because i could bend it easily. I will be buying music wire, but what diameter yo you suggest? My welding rods are 1/16th, and it fits well in the slot. Do you guys think that 1/16th music wire will be strong enough? Also, how do i bend it? Do i need to heat it? Thanks

Vice, heavy duty pliers ... bend COLD. 2mm is good for a model up to 1kg if made up in a V style (two legs each side) ... will take up to 500gr if single leg each side. My SE5 has V twin legs of 2mm control rods used for UC weighs about 600gr .. I can't buy good music wire - so I order packs of long control rods at 2mm ... make excellent legs and other uses ...

Nigel

[Yakfishingfool]

leave strut end attached to wing and then put "dots" of velcro on both sides of other end and a strip across the bottom of plane, Reach strut as far as needed to tighten it and push down on velcro. Should stick well. This way easy to remove if you want the wing off easily as well. Scott

[hoghead5150]

the stock landing gear is decent, so why not just go buy a new set? most hobby shops that carry hobbyzone planes have these in stock since the super cub is so popular.

http://www.horizonhobby.com/products...cub-lp-HBZ7106

[CaptainMalick98]

Thanks guys. I'll be buying new landing gear and using shrink tubes to fit larger wheels on. I also decided i want to "modernize" the cub, so i'll use my own Tx and rx, will use a brushless exceed rc alpha 450 (890 kv) will get a 9x6 prop, and ill use a 30 amp ESC. I know from the forums that 2100mah ish batteries can fit, but given that i use a small Rx, do you guys think there would be room for a 5000 mah battery?
Thanks

[JetPlaneFlyer]

A 5000mAh battery would be way WAYYYY too heavy, even if you could fit it in. If you want the plane to fly well then you should be looking to maintain close to original weight. That would put you around a 3s 1800mAh lipo. A little larger would probably be ok (the 2100mAh for instance) but 5000 would be like trying to fly with a brick on-board.

[Fishbonez]

5000mah???
+1 Jet. Maybe a typo here, but if not got to agree with Jet on that. To heavy of a battery and also a lot of unnecessary modification. "Dont fix what is not broke"