RE: Think I can do it? Magnum with retracts
That wing I believe is only 1/2" thick at the thickest point (been a while since I looked at my magnum). The ONLY method you'll make work is if you built some massive blisters on the top of the wing, or built an under wing pod like the A4 skyhawk had. You're at a disadvantage in that if you did find small enough retracts to fit in the wing or at least relatively close to it, they will probably not be strong enough for the weight of the magnum never mind the speeds it lands at. Even putting a fixed gear in that airplane is difficult to do strongly, You're going to have a hard time even finding wheels that would fit into that wing with a wire gear, if you use 3/16" wire (which would be very small and probably bend easily at landing speeds) and a pylon racing wheel (which is still 1/4" thick at the axel portion) by the time you have the radius'd bend in the wire you're going to be at the VERY least 1/2" thick in the wheel and wire alone assuming you make a VERY tight bend and solder a washer on to retain the wheel. There are narrower wheels out there, but they're for park fliers and the like, I suppose you could machine some aluminum ones to 1/8" thick, but if you're going to go to that trouble you'd be just as far ahead to put a fixed gear on there since the drag from an open wheel bay is going to be the same if not more than a very narrow wheel with wire gear.