Motor adapter spacing

[Mark Farver <farver@mindbent.org>]

I am designing an adapter for one of MetricMind's AC drive system.  I have
all the tranny measurements and the face measurements of the motor.  My
current design has two 1/2inch aluminum plates seperated by a spacer.
(The motor shaft on this particular motor is almost 3.5" long)

The problem is the spacer, the best idea I've seen is a ring made from a
length of 8" OD, 1" thick wall aluminum pipe.  I could have my plates made
with a nice alignment lip to center the pipe and keep the shafts aligned.
However, I have no idea where I can find a 3-4" length of this pipe.

What other ideas would others recommend?  A simple block of aluminum
with a hole drilled thru?  Four plates stood on end and screwed together
to form a box?  What would be a cost effective and strong way to seperate
the plates, while still retaining the critical alignment needed?

Thanks
Mark



-- 
"The greatest dangers to liberty lurk in insidious encroachment by men of
zeal, well-meaning but without understanding."
-- Justice Louis O. Brandeis, Olmstead vs. United States