ATM Attaching Spider and Primary cell to a Square Tube

[Brent Hutto <BHutto@InfoAve.Net>]

If a Newtonian telescope is built with a square tube, does that mean 
there's no convenient way to use a 3-vane or 4-vane spider such as a 
Protostar or similar? Same question for a round aluminum-frame 
primary mirror cell.

It seems like there would no way to orient the three or four 
attachment points so that there's a tube wall at the right distance 
for all of the points simultaneously.