TREYisRAD... sorry, musta missed your post. I will inquire about square tubes.
Pizzaluvr... The price per foot for the .875 od (flat to flat) x .032 wall is $20 plus shipping. Based on my CAD drawings, the ID of the hex tubing is .811 flat to flat. This will make the .812 OD barrel and feed tube a VERY tight fit. The valve tube is .875 OD, which will make for a problem
You might be able to create a custom valve, hammer, etc to accomodate theodd size hex tube... or you could solder the hex barrel and feed tubes to a standard valve tube.
If you decide you are interested in building using the hex tube, I will order the tubing. If not, and no one else shows any interest in the hex tube, I will NOT be ordering any of it.
I'm trying to get this order in by Wednesday, so this is the last call for anything "interesting", anyone might want from Rotax. I suspect my next order will be in June, or July.