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From: "leex0248@student.tc.umn.edu" <leex0248@student.tc.umn.edu>
Subject: Assembly using the Adept Robot
To: plutchak@lager.geo.brown.edu
Message-ID: <23281.leex0248@student.tc.umn.edu>
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Date: Thu, 27 Jan 1994 04:47:34 GMT
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I'm doing a project that involves using the Adept robot with impedance 
control to assemble a graco ball valve.  Most of the processes seem to be 
working ok, except for couple of things:
     1)  After the ball is inserted into the valve, I have no way of 
knowing if the slot in the ball is oriented in the right way for it to 
accept the operator.  (If you are not familiar with the graco ball valve 
design -- the ball has a cylindrical hole in the middle through which the 
fluid is passed.  To operated this ball, there is a rectangular slot on 
normal to the axis of this hole to which a metal rod is mated.  And this 
rod is turned externally to change the orientation of the ball.)  Anyways, 
I can get the axial orientation of the hole to align ok using premade 
fixtures, but I cannot guarantee that the slot will aligned properly, so 
that the rod can mate with the ball.  An error occurs about 50% of the 
time.
    2)  The above mentioned rod also needs to have two packing rings 
attached to it before inserting into the valve for mating with the ball.  
Because of tight tolerances, a considerable force  is required to insert 
this rod all the way into the valve so that a successful mating can occur.

So, that's the jest of it.  Any helpful comment, suggestions, or 
references should be sent to :  leex0248@gold.tc.umn.edu

Thanks much.
Sam
Samuel Y.  Lee
