Super Cub Build

[Gabe]

19K's pretty much got you covered there. The only difference in sport and electric "E" props is the pitch towards the center of the prop. It's made to spool up really fast for electric motors. To be honest, I've never really noticed a difference unless I'm looking at the ICE data logs. The E props turn more amps way faster.

A bigger prop will give you more thrust and speed if your motor can turn it - which I believe it can.

A slow fly prop is just that - it allows the prop to spin at high rpms with maximum thrust, but it's pitch speed is limited. This allows for easy, short takeoffs, and really simplifies the landing process. If you're a newbie to landings then the slow fly props are a great tool. If you are comfortable landing then go for the regular props.

[r/c basher]

Thanks Gabe and 19, for explaining the differences. I think I might go with this prop- www3.towerhobbies.com/cgi-bin/wti0001p?&I=LX1548&P=7 .

While Im at it I might pick up some wheels- www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXAZE9&P=7 . I dont know if I should go with 2 1/2" or 2 3/4" wheels though. Ill be flying off of some tall grass.

I ended up not ordering the hxt900 servos. I dont feel like waiting a month to get them, by then I probably wont need any wheels. After saying that I might get some skis too, that way I save my floats for the water.

[19000rpm]

That prop should work well.

It won't hurt to get the 2 3/4 wheel or even the 3's. They are super light. Get some aluminum tape at the hardware store to wrap around the axle so that the wheel will fit nicely.

[r/c basher]

I think the 3's would be a better choice, I fly off of a hay field. Last night I made a mount and got the motor mounted. All I need to do now is mount the electronics and get myself a prop, then Ill be ready for the maiden flight.

Ill admit it my motor mount is pretty crude and homemade but it seems sturdy, and is one of the better things that Ive made from scratch. What I did was cut off part of the plastic mount and used that for a base. Then I cut a piece of wood to the proper space that I needed and drilled holes in it and screwed it to the plastic mount. And then used the metal mount that came with the motor and screwed that to the block of wood.

For some reason its not letting me attach my pictures, it must be just in the plane section, because in every other thread outside the plane section it lets me. Ill post some pictures in the general rc section.

[r/c basher]

Last night I got the servos and esc installed, and programed the esc and dx6i. After programming the esc I dont have the problem with the motor spinning a hair backwards then running forward like normal anymore. All I have to do now is get the AR6200 installed and hopefully today be able to go to the lhs and pick up a prop.

One question on the AR6200 though, when I go to mount it does the antenna have to be visible from the outside after I put the wing on? Or is the 2.4ghz strong enough to go straight through the foam?

[19000rpm]

The antenna can be internal. Route it away so it doesn't touch an metal or CF. Main thing is to range test it before you fly it. That will confirm you are getting a stong enough signal.

[r/c basher]

Oct 9, 2010 10:19:23 GMT -6 19000rpm said:

The antenna can be internal. Route it away so it doesn't touch an metal or CF. Main thing is to range test it before you fly it. That will confirm you are getting a stong enough signal.

Thanks 19.

I did the maiden flight last night. It went fairly well without any incidents, it has alot more power now and I actually can do outside loops. It doesnt have a ton more straight line speed but does have almost unlimited vertical. I think its a little nose heavy though because at full power it doesnt pitch up alot, like I thought it would. When I come in for a landing it pitches down more than it use too.

I took it out this morning to fly and the second maiden didnt go to well, I was coming in for a landing, and landed a little rough, and then the firewall broke off. I guess the firewall couldnt handle all the extra power, atleast it didnt break off in the air. I dont think it was the landing that did it, Ive had way worst landings.

The firewall just came unglued, it didnt break, Would I be able to fix this with some gorilla glue and have it hold? It was a pretty clean break. The mount is still in one piece. I would really hate to have to buy a whole new fuselage. Thanks.

[Gabe]

Epoxy or Gorilla glue should be aye-OK. I would get a few cf rods and slide them through the firewall mount into the firewall. Test fit them so they go into the firewall a few inches (if there's) room and trim them so they're flush with the mount. You may have to drill a few holes in the mount. Slather them with you glue or epoxy, slide them in place, cover the mount with glue or epoxy and slide it into place. The cf rods will act as bolts and give you some added strength so it doesn't break off again.

Double check your COG too. You want her slightly nose heavy, but not too much. Also, you can program in some spoilerons with your DX6i. If you haven't used them yet, they really make landings easy. They force the nose up without destroying too much lift. If you need help programming let me know.

I would recommend taking her way out, kill the power and start your glide in, about 100 yards out kick on the spoilerons and give her some down elevator because she's gonna flare up. Manage the throttle and walk her in. Use your rudder to keep her straight and go easy on the roll. If you Bach the landing, give her full throttle and let her build speed before attempting to turn. Its a good idea flip the spoilerons off before turning. There's a little more of a tendency to stall in a turn at slower speeds with the spoilerons on.

[r/c basher]

Oct 10, 2010 10:29:47 GMT -6 Gabe said:

Epoxy or Gorilla glue should be aye-OK. I would get a few cf rods and slide them through the firewall mount into the firewall. Test fit them so they go into the firewall a few inches (if there's) room and trim them so they're flush with the mount. You may have to drill a few holes in the mount. Slather them with you glue or epoxy, slide them in place, cover the mount with glue or epoxy and slide it into place. The cf rods will act as bolts and give you some added strength so it doesn't break off again.

Double check your COG too. You want her slightly nose heavy, but not too much. Also, you can program in some spoilerons with your DX6i. If you haven't used them yet, they really make landings easy. They force the nose up without destroying too much lift. If you need help programming let me know.

I would recommend taking her way out, kill the power and start your glide in, about 100 yards out kick on the spoilerons and give her some down elevator because she's gonna flare up. Manage the throttle and walk her in. Use your rudder to keep her straight and go easy on the roll. If you Bach the landing, give her full throttle and let her build speed before attempting to turn. Its a good idea flip the spoilerons off before turning. There's a little more of a tendency to stall in a turn at slower speeds with the spoilerons on.

Thanks Gabe. Ill try using gorilla glue and carbon fiber rods to remount the firewall on again. Hopefully this time it wont come off. Does it matter the diameter of the cf rods I have some rods left over from previous crashes with my honey bee fp?

Spoilerons sound great but I think you have to have ailerons inorder to use them? Right now I dont have any ailerons Im still on 3ch., throttle, rudder, elevator. Im using my dx6i with the super cub. Ailerons are the next thing on my list.

I weighed my super cub and to my surprise it weighs about an ounce less than when it was stock. According to horizons website the flying weight is 25.20 oz. and when I weighed my super cub with the battery in it weighed 24.05 oz..

I just looked at my spare parts for my hbfp and I have this carbon fiber tail boom thats to short to use on my bee I think it would make my firewall alot stronger if I used it, instead of a cf flybar.

[19000rpm]

Your straight line speed is being slowed by the big wing.

I can't think of a better place for you motor to come loose. I've had that happen in the air and, as you can imagine, that's utter chaos.

Following Gabe's advice; using some rods to anchor the firewall will really help. I'd epoxy the rods to the firewall and then GG the assembly into the fuse.

Sounds a little nose heavy. Check your CG. It should be between 1/4 and 1/3 of the wing cord measured from the leading edge. You might find adding a bit of up elevator will solve your handling issues.

[r/c basher]

Would super glue work ok in the place of epoxy? Because I dont have any epoxy. Ill probably buy some the next time I make an order. Ill try moving the receiver back some to see if that helps with the cg. Ill check my cg once I get everything back together.

I might be adding ailerons sooner than I thought, then I can shorten the wing and have spoilerons. And alot of other benefits.

[Gabe]

Ah, I forgot that you don't have ailerons.

Yes, CA glue (superglue) should be ok so long as you use the cf rods. It's not optimal, but it should work. The superglue/CA glue will have a tendency to crack if there's any impact though.

As far as the COG goes, the receiver won't make a noticeable difference. I would suggest 1/8-1/4" movement of the battery either forward or aft (towards the tail). In your case, slightly aft by 1/8 or 1/4" at a time. Just be sure when you check the balance points to tip the plane as far back as you can by the nose. If it still dips forward, you're good. If it tends to balance perfectly or likes to nose up a little, don't take a chance and just move the battery forward a smidge.

I like to take a sharpie and mark where the front on the battery goes. Remember though, if you use different size batteries or batteries with a different number of cells, you will need to adjust the battery location again.

Finally, make sure the battery is strapped down, velcro'd, or secured somehow. That's how I lost my first Darkside Stryker.

[r/c basher]

Thanks Gabe. The battery compartment doesnt allow for the battery to be moved at all. I think its time to do the battery tray mod that some people do so they can fit longer batteries. So then that way I can adjust my COG. The mod isnt to hard just dremel out the back side of the battery compartment and cut out some foam then thats it and secure the battery with the velcro strap.

[Gabe]

Sounds easy enough. I'd go for it.

[19000rpm]

I haven't had much good luck using CA on the plastic they use.