shd3920

I am building a low-wing from scratch and need to know where to place the main landing gears.
Should the wheels be located underneath the second or third open bay from the center?
How far back from the leading edge should they be?
It will be a tricycle setup and the wing is 34" span X 6 1/2" wide, and I am adding ailerons with two servos.

Thank you.

LouisB

When an aircraft takes off, it rotates around the centre of gravity (CoG or CG). So you should place your main landing gear just a little behind the CG, towards the tail. Not too much else the aircraft will battle to get airborne. The nose wheel would obviously be installed at the nose.

shd3920

Thank you Louis. Would the 2nd bay from the center be good?

flyingagin

I would go with the third bay. More lateral stability is all ways a good thing. But farther out might give you some problems and with a hadrd landing you could be looking at a failed wing. But the third is safe on all counts.

Ken

BMatthews

The farther out the wheels are the easier it is for touching clumps or other obstacles with one side to kick the model out of line. But too close in and the model can be upset by side wind gusts easier.

Because this is a trike gear model I'd suggest that your landing gear mount blocks or plate would be glued directly to the main spar. As for spacing the second picture suggests to me that having the wire leg drop down at the second wing rib from the center with the stub axle for the wheel bending outward from that would put the wheels just a little into the third rib bay. And that looks about right to my eyes. It's wide enough for stability and narrow enough that you shouldn't see the model get kicked around too badly by stuff on the ground.