On Tue, 08 Jul 2014 19:32:41 -0500, F. George McDuffee
wrote:

On Tue, 08 Jul 2014 15:50:31 -0500, Tim Wescott
wrote:

snip
The thing would need to work with an existing piece of equipment, which
has no solid external reference points to provide for good alignment to
the shaft on the device under test (or, for that matter, a really easy
way to get centered onto a shaft).
/snip
=====================
This simply adds another spec/requirement. You will have to
have some way to rigidly mount the test assembly. This
seems to indicate that either the test assembly mount and/or
the absorber mount must be adjustible in the XYZ directions
and rotations about the X and Y axis. Then you will need a
gage set-up to align the two shafts.

There are a ton of videos on YouTube on shaft alignment
heres one to start
https://www.youtube.com/watch?v=9JCbdDNyUPQ

A sleeve with reamed holes [several diameters deep] for the
shafts may be accurate enough. If not, here are some URLs
that may give you some ideas [most likely you already have
the drop indicators] or align off the couplings if you use
flange gear type couplings with external driving bands..


http://www.google.com/search?q=dial+...w=1207&bih=523
http://www.mitchellinstrument.com/me...arter-kit.html
http://www.solarstop.net/mrshims/shaftalignment.asp
http://www.skf.com/group/products/ma...a11/index.html
http://www.skf.com/group/products/ma...a20/index.html

http://www.google.com/url?sa=t&rct=j...,d.aWw&cad=rja


Haw about a prony brake that fits right on the shaft of the motor??
Again, we really need a picture, or at least a better description of
what you are working on.