Monday, July 18, 2016

Checking a Drill Press Spindle using a Lathe

Well, I was unable to find replacement parts for the drill press (who can find Guardian Power Tools, let alone even a manual for FDM-58-12S?).  As a result, I had to check the spindle to see if it was even worth any more work.  To do this, I used two centers (a live on in the tail stock).  I put up my dial indicator, and took measurements at three points (any other points are pointless, pardon the pun, because they are not bearing surfaces).  The three points are :

The reason for these three points are :
  • A is the lower bearing surface - this has to be accurate - but, if it is out of round, it was probably manufactured badly.
  • B is the upper bearing surface - and this is where you will see the most "out of round" as you turn it by hand.
  • C is the spline area - if this is out of round, the thing was manufactured poorly.
The spline isn't "as" necessary, since it isn't a bearing surface, but it will wear faster if it isn't.  So, I threw it all onto the lathe.  I don't have a drift key, so I cannot get the chuck/arbor off, so I already know I am inaccurate on one end.  The dial indicator specified that I was about 0.002" out of round at the lower bearing area.  I moved to the middle, and found I was only 0.004" out of round.  Surprisingly, that is pretty good for a drill press.

The maximum out-of-round on the upper bearing surface is 0.004"

This means I can simply replace the bearing, and put it back together, and have a drill press in great shape!

No comments:

Post a Comment