I want to modify my Model Tech P-47 retract's for a 3" dia tire. Anyone have any ideas on what to use for the larger wheel cups?

If you're referring to the recess in the wing where the wheel sits when retrated, then simply use 1/16th inch balsa sheet. When you wet it, it will bend easily enough to wrap around the diameter of the recess.
Dennis-

Thanks DB, That is what i am referring to. It came with plastic cups for the wheels to sit in when retracted. Besides being ugly they are to small for 3" dia wheels.

I've used styrofoam cups cut down to size for wheel wells - but you have to go to some fast food joint to get the right size

Jerry

Thanks Tailskid, I was also thinking about a coffee cup before but i like the idea of the sheet balsa to fill in all of the well then painted. Humm may end up looking so good that I will have to order a set of air retracts for her.

I looked at one of these kits, and my biggest disapointment with it was the size of wheels. I studied it, and don't think there is enough room for larger wheels without cutting into the spar. It appears to run right at the rear edge of the wheel openings. Let us know if you can work it out.

If you want something more durable than styrofoam try some cheap plastic glasses. Go to your local dollar store, WM or wherever you'd like and look for the plastic tumblers. They are very cheap, round, and light weight once you cut them down to your depth and they are much easier to paint and maintain.