RE: KMP 87" Yak-54 What do you Think?
For people interested in the wing tube strength I made some measurements, and assuming the grade of aluminum in the tube is correct(maybe a big assumption), it should be strong enough.
The tube is a 25mm(.9842) tube with a 2mm(.0787) wall thickness, which as stated should be fine if a good grade of aluminum was used. I have an old 1" tube from some plane from a few years back(I can't remember which one) and it has a wall thickness of .050, so the KMP one is significantly thicker, which is not conclusive as to its strength, but at least it isn't thinner.
More interesting facts. I thought the tube fit was a bit loose and I was right. The internal measurement of the composite housing tube is 1.002, leaving about .0177 clearance, which is a bit too sloppy in my book, but probably not a big problem....BUT, the interesting issue is that you may be able to find a very straight CF tube that is an accurate 1.000" inches and it may just fit in the existing mounting tube. My old 1" aluminum tube won't quite fit, but after measuring it that isn't a surprise since it varies from 1.000 to 1.0030, and it isn't oval, it just varies by that much. Even if you find a 1.000 tube, 2 thou may not be enough since the housing tube probably varies in size too, but it is worth a try. A little mix and match and we might be able to come up with a good CF option.
Maybe if anyone out there has a 1" CF tube and has the ability to measure it accurately, they can tell us what it is and there may be a good option available for the KMP owners out there. I'm going to write the couple of manufacturer's I know out there and see if they'll send accurate measurements to me.