berrs003

Hi all,

I've had a ripmax Trainer 40 for over 2 years now and want to try and explore the flight envelope to the max.
I'm on a tight budget and was thinking of making some performance enhancing upgrades instead of buying a new frame.

i'm mainly looking for vertical/aerobatic performance out of the trainer over the sedate machine its designed to be.
I'm just experimenting to see whether you can actually make a trainer go near unlimited vertical on a .42 size.

I have a thunder Tiger 42 up front and it's been swinging a 11x7 prop (APC).

Was wondering whether putting a 12x6 would be viable on this engine or would an 11x4 be better?
perhaps someone could even explain the best type if i've got it wrong?

I know the "trainer" is designed to have alot of drag but surely theres a way?


o btw - theres the link for the model http://ripmax.com/item.asp?itemid=A-...tegory=010-010

bkdavy

My Feedback: (1)

With that size engine (is that the GP or the Pro?), a 12x6 will be way over propped, and you'll see a big performance hit. If you want improved vertical performance, go with a higher thrust prop - try a 12x4.

Brad

spiral_72

The best prop I've used for a .46 was a 12.25x3.75" APC. I know yours is a .42 but try it. It has the large diameter for pulling and low pitch to unload the engine. It's not a high speed prop. I doubt if you'll have unlimited vertical but it'll pull A LOT harder.

Move your CG back. You'll have to play with this, but the closer the CG is to the tail, the more resposive the plane will be. Maybe move the CG 1/8" at a time with a flight to test it. There will come a time the plane is very unstable. For aerobatic use, use want to be just ahead of that.

You might try lifting the rear of the wing, 1/8" or maybe 1/4" to change the incedence(SP?)

If you have any lead in the plane, move things to remove it. Anything you can do to lighten the plane will help with vertical. You can buy foam wheels instead of rubber. You won't believe how much rubber wheels weigh.

You'll need to remove the dihedral in the main wing. Google it or look here on RCU.

Buy some 1/4" balsa stock, maybe 1/4" x 2" or larger and cut your own ailerons to replace the puny little ailerons that come on it.

Increase your rudder size but 50%. You'll have to build a new one. Not a big deal really.

Use the 1/4" x 2" or larger balsa stock and increase the size of your elevator. -Might be optional.

Lighten the plane man. Micro servo for the throttle, foam wheels, no huge Rx battery, maybe carbon pushrods. Plastic spinner weigh less than aluminum. You might consider removing the spinner or use a prop nut instead to unload the engine a bit.

That's what I'd do.