Drill press pulley and motor shaft wear
Close
Login to Your Account
Likes Likes:  0
Results 1 to 9 of 9
  1. #1
    Join Date
    Sep 2014
    Country
    UNITED STATES
    State/Province
    Oregon
    Posts
    3
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    0

    Default Drill press pulley and motor shaft wear

    I'm fixing up a 60's era Rockwell/Delta 17" variable speed drill press - this is the type with a reeves pulley system. It looks like the motor shaft and motor pulley bore have been worn to the point of a fairly sloppy fit and I'm looking for advice on a good fix.

    I had first thought the motor shaft was bent because it shows a degree of runout (~0.015" at the shaft end). After closer inspection I'm thinking now that it's actually not bent, but out of round and maybe slightly tapered due to wear. Unfortunately the wear is also present on the inside of the pulley bore, probably because the press was run in this state for some time. The replacement pulley assembly is crazy expensive, so I'm hoping to be able to salvage this one, even if I have to replace the motor.

    The shaft and bore are 0.75" (prior to wear).

    I should note that I'm primarily a woodworker, and I'm not set up to do precision metal work. I'm prepared to hire out any machine work that can't be accomplished with the tools I have available.

    I can post pics or any other measurements if helpful. Thanks!

  2. #2
    Join Date
    Sep 2007
    Country
    UNITED STATES
    State/Province
    Washington
    Posts
    5,094
    Post Thanks / Like
    Likes (Given)
    171
    Likes (Received)
    1439

    Default

    Got pics? If there's enough material, the pulley can be bored out and a bushing put in. The motor shaft is a different story though.

    Regards.

    Mike

  3. #3
    Join Date
    Jan 2013
    Location
    canada
    Posts
    860
    Post Thanks / Like
    Likes (Given)
    299
    Likes (Received)
    422

    Default

    you are not set up to do precision metal work. then you need to find someone in your area to do this for you. up to you to determine if you want to spend xxx amount of dollars on repair.

  4. #4
    Join Date
    Sep 2014
    Country
    UNITED STATES
    State/Province
    Oregon
    Posts
    3
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    0

    Default

    I took a few pics this morning. The shaft looks like it had some heat damage to me, and the key was starting to roll over.

    img_2117.jpgimg_2116.jpgimg_2118.jpgimg_2119.jpgimg_2120.jpg

  5. #5
    Join Date
    Mar 2005
    Location
    Palmer, Alaska
    Posts
    3,603
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    743

    Default

    You need to have the motor shaft keyway section turned down ~.020 (remove bearing first, and then shaft from motor..) This allows weld to stick well, and weld joint area will be below new OD of shaft..

    Mig weld shaft in worn portion, well over size... ( do not hit bearing area) full length of keyed area, just slop it on. Just bubblegum steel used in motor shaft... Nothing special.. Try to keep heat down, so you do not melt aluminum on armature..

    Using a lathe. Indicate off of untouched/welded bearing surface, to cut a live center hole in outboard end.. (if outboard end is threaded, install a bolt, and cut center hole in that) Have welded area on shaft turned to .760..

    Recut keyway on mill.

    Bore pulley to ~.761

    Most pump repair shops, will know exactly how to do this.. I do not recommend spray weld in this application..

    Reassemble..

  6. #6
    Join Date
    Sep 2014
    Country
    UNITED STATES
    State/Province
    Oregon
    Posts
    3
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    0

    Default

    Good info. A couple questions...Would a machined bushing work as well as welding up the shaft? Would it be worth increasing the bore size to a standard dimension, maybe 7/8", in case the motor needs to be replaced in the future? If I did, I would lose more of the keyway (3/16" square stock) on the bore, so I'm wondering if that would complicate the repair.

  7. #7
    Join Date
    Mar 2005
    Location
    Palmer, Alaska
    Posts
    3,603
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    743

    Default

    Bushings and keyways in sliding applications, do not get along..

    Shaft will not be worn evenly, and a bushing will need to be silver brazed or equal to shaft.. 5 minutes with a MIG welder, and build up is done..

    Since keyway is already worn, a thin bushing over worn area, will wear just that much faster..

    Literally only a couple hours work, to fix/weld it right.. A much larger hole in pulley.. will weaken it , and keyway disappears.

    That ancient Reeves variable V belt drive is inefficient...

    I would dump the Reeves drive myself. Put a 1/3 bigger 3 phase motor on it, and run with a VFD, and a set of fixed pulleys... approx middle diameter of Reeves pulleys..

    Variable speed over an even wider range, that it has now...

  8. #8
    Join Date
    Mar 2014
    Location
    BLACK MOUNTAIN NORTH CAROLINA USA
    Posts
    360
    Post Thanks / Like
    Likes (Given)
    356
    Likes (Received)
    234

    Default

    Appears to me the pulley has been repaired before ? Surely the pulley did not come from factory that way ?

  9. #9
    Join Date
    Aug 2005
    Location
    Tucson AZ
    Posts
    6,238
    Post Thanks / Like
    Likes (Given)
    9191
    Likes (Received)
    2924

    Default

    Quote Originally Posted by plothoundsman View Post
    Appears to me the pulley has been repaired before ? Surely the pulley did not come from factory that way ?
    I suspect that you are correct. Probably with too much clearance so here is the same problem again.


Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •