Physics of Landing gear: An existential Inquiry into a modded Tail Dragger's petulance

Absolutely correct Ed - as usual :-)

"Ralph Jones" wrote

A -REALLY- easy way to find the 15 degree point (after the balance point under the wing is correct) is to tilt the model over on it's nose 15 degrees from level flight attitude. When the wheels are in the right place, it will not tilt forward or back, but nearly be balanced leaning at that 15 degrees.

As far as the toe in-toe out debate, try going to extremes, (5 degrees or more) both in and out. Fast taxi it, or even take off. Which is better?

I tend to fall firmly on the side of toe out for tail draggers.

I believe that the drag is not as important for keeping it straight, especially on grass where there is no traction, or little. Where the weight is pulled when it goes up on one wheel is very important, (it will get enough traction to turn the plane, even on grass) and in will only make it tilt more, and weave side to side more.

Don't believe a word anyone (including me) says. Try a very noticeable in and out, and see what works for you. You will know, for sure what works, then.

Dave, Your AOA it kinda high with that tall gear and that has a bad effect (imho) If you raise the tail will your prop clear enough? How about a 3 blade or 4 blade prop? mk

You're right, it makes a big difference whether you are flying from grass or pavement. You really don't want toe-out on pavement.

I think some are making the wheel placement too complex. It's not rocket science. Just place the axle under the leading edge of the wing when looking down on the wing with the bird in it's T.O. attitude. A tried and proven technique.