Subject:
Re: Debuncher Motorized Quad Stands
From:
David Peterson <peterson@fnal.gov>
Date:
Tue, 06 Jan 2004 09:18:10 -0600
To:
Keith Gollwitzer <gollwitz@fnal.gov>

Keith,
Here are some suggestions for the next version:

0) We like the Phoenix connectors and having (most) everything accessible from the aisle.

1) Make limits easier to fine tune.  Instead of set screws on a smooth rod maybe a 
   threaded rod with adjustable stops would allow for finer adjustments.  The limits are 
   critical to operation and I would like a design that will not slip too far if something 
   is loose.

2) Uniform set screw sizes.  If set screws are used, try to make things uniform.

3) Independent LVDT and limit brackets.  The brackets should be directly attached to the 
   moving part of the stand and failure of one bracket should not affect the other.  We 
   see a small LVDT error due to flexing of the bracket.

4) Unipolar LVDT? Maybe? Digikey has LVDTs that run off of 24 VDC and provide unipolar 
   output.  This would simplify wiring and power distribution.

5) H&V same ratio?  Not too important but would help during alignment and test.

6) Reduce backlash.  This is really needed for horizontal motion.

7) Remember motor power restrictions.  We are able to deliver 4 amps at 24 volts and can g
   o to 48 volts if needed.  The present motors are running at about 1 rev/sec. 

Thanks,
Dave


Keith Gollwitzer wrote:
Hello,
   During the Fall 2003 shutdown 10 Debuncher motorized quad stands were installed. I 
understand that there were some problems with the installation of the stands and motors. 
We are going to make 20 more such stands and are reviewing the design of the Debuncher 
motorized quad stands. I am looking for your input. If you can comment on any issues 
concerning the motorized quad stand system and/or make any suggested improvements, 
please send them to me. Steve Werkema and I are still working on getting a mechanical 
engineer assigned.
                               Keith Gollwitzer