Pratt & Whitney 12 x 30 Model C - Removing apron front
Close
Login to Your Account
Page 1 of 3 123 LastLast
Results 1 to 20 of 41
  1. #1
    Join Date
    Jan 2016
    Country
    UNITED STATES
    State/Province
    Vermont
    Posts
    17
    Post Thanks / Like
    Likes (Given)
    3
    Likes (Received)
    0

    Default Pratt & Whitney 12 x 30 Model C - Removing apron front

    I am in the process of refurbishing my 1957 P&W 12x30 Model C lathe and need some help/advise on removing the front of the apron. The brochure says it's EASILY removable but mine seems to be hung up somewhere. I have removed the 9 cap screws, all the handles,and the set screw holding the threading dial. Any shaft going through the front casting looks like it should slip through. I've gone as far as driving oak wedges between the front and back casting and have driven them apart about 3/16" all around. I'm afraid to drive them further for fear of cracking the front casting although so far everything about this machine impresses me as far as beefiness. If anyone has removed the front apron on their lathe I would appreciate any help you might offer. I will try to attach some pictures.
    Attached Thumbnails Attached Thumbnails img_0910.jpg   img_0911.jpg   img_0912.jpg   img_0913.jpg  

  2. #2
    Join Date
    Jul 2004
    Location
    Houston, TX USA
    Posts
    32,126
    Post Thanks / Like

    Default

    Might be helpful
    Attached Thumbnails Attached Thumbnails pw-c-apron-.jpg  

  3. #3
    Join Date
    Jul 2011
    Country
    UNITED STATES
    State/Province
    Oregon
    Posts
    478
    Post Thanks / Like
    Likes (Given)
    126
    Likes (Received)
    288

    Default

    I think you are catching on the interlock rod that keeps the thread lever from being engaged while the feed lever is engaged or the other way around. If you look just the right on the longitudinal feed lever and also just to the right of where the thread engagement lever is there are two shafts sticking through the casting. Each has a set screw that locks them in place. You need to remove the set screw in each and tap the shafts towards the back of the cover.....

  4. #4
    Join Date
    Jul 2011
    Country
    UNITED STATES
    State/Province
    Oregon
    Posts
    478
    Post Thanks / Like
    Likes (Given)
    126
    Likes (Received)
    288

    Default

    You may have already bent the rod with your wedging. It is pretty small diameter. Let me know if that works. Do you have the manual? Good drawings in there.... I think I have a pdf somewhere.

  5. #5
    Join Date
    Jul 2005
    Location
    Cottage Grove, MN 55016
    Posts
    8,414
    Post Thanks / Like
    Likes (Given)
    4414
    Likes (Received)
    4935

    Default

    I would screw in some long Allen cap screws so the cover hangs on them. Then see what happens. Then I would drill / tap the dowel pins and see if you can lower the cover. I'll do some research and add more. Rich

    I found this manual: http://neme-s.org/Shaper%20Books/Pra...WModCParts.pdf

    Figure 18 & 19...I would remove the star nut on shaft 27 and the thread dial 17 on figure 19 and see what happens.

  6. #6
    Join Date
    Jul 2011
    Country
    UNITED STATES
    State/Province
    Oregon
    Posts
    478
    Post Thanks / Like
    Likes (Given)
    126
    Likes (Received)
    288

    Default

    Thanks Richard for finding that. If you look at section GG figure 19 you can see the interlock rod I mentioned and why it won't come out with that in place. I do think Richard is right and the nut he mentioned should come of as well as the thread dial itself by loosening the set screw on the side of it.

  7. #7
    Join Date
    Jan 2016
    Country
    UNITED STATES
    State/Province
    Vermont
    Posts
    17
    Post Thanks / Like
    Likes (Given)
    3
    Likes (Received)
    0

    Default

    PMtool - Your suggestion was spot on. I removed the wedges to relieve the tension, removed the two set screws and tapped in the shafts. After that things loosened up with a little tapping and the apron front came off.Luckily the small rod wasn't bent. Originally I had removed those screws but replaced them as the diagram in the pdf brochure I downloaded, showed them attached to the cover. I think if the clutches had been in just the right orientation the rod would not have hung up. I hope this is a correct assumption because it's going to be a bear reassembling the cover while getting the rod shafts into the cover. Thanks again for you help and the other contributors suggestions.

  8. #8
    Join Date
    Jul 2004
    Location
    Houston, TX USA
    Posts
    32,126
    Post Thanks / Like

    Default

    If you need the op manual pdf just private message me your EMAIL address

  9. #9
    Join Date
    Jan 2016
    Country
    UNITED STATES
    State/Province
    Vermont
    Posts
    17
    Post Thanks / Like
    Likes (Given)
    3
    Likes (Received)
    0

    Default

    John, thanks for your offer of the op manual. I was fortunate enough to get the original manual that came with the lathe. I also have a copy of the parts list which I may have downloaded from one of your earlier posts. Related to this same subject do you know if there exists manuals on the disassembly and assembly of this lathe?
    Thanks, Richard

  10. #10
    Join Date
    Jul 2004
    Location
    Houston, TX USA
    Posts
    32,126
    Post Thanks / Like

    Default

    Highly doubtful. In a bit less than fifty years of old machine tool pub collecting, I have never seen or heard of such for this make. Only make known to me that provided such was Cincinnati Milling Machine

    There is an excellent reason for this in the case of P&W. For a very long time - if your P&W needed working on, you just telegraphed (or later telephoned) and a factory service tech would be at the train station by and by.

    The P&W parts books/manuals - especially the older ones - are lavishly and competently illustrated

    Quote Originally Posted by greenmtfan View Post
    Related to this same subject do you know if there exists manuals on the disassembly and assembly of this lathe?
    Thanks, Richard

  11. #11
    Join Date
    May 2013
    Location
    Shasta County, Ca. USA
    Posts
    1,017
    Post Thanks / Like
    Likes (Given)
    92
    Likes (Received)
    255

    Default

    I am really curious how this procedure worked out for putting the cover back on. I have this chore coming up soon. I looked at the interlock assembly on my Model C and I see no way that the cover can go back on the apron unless the interlock assembly is installed beforehand.

    I can envision a tool possibly to spring the interlock shaft towards the tailstock side enough to let it slip over the feed clutch drum.

    When I pulled it off I experienced the same hang up and I believe because the half nuts were not engaged mine actually was able to spring to clear the feed clutch drum.

    I dread reassembly based on the fact the bevel on the interlock shaft is on the opposite side of the clutch drum.

    Anyone out there put one back on?

    I agree with John above that Pratt and Whitney went above and beyond with illustrations. I recently was involved repairing an American Lathe from the late 60s and the parts manuals etc. were not the greatest and in some cases left most of the details up to you to stumble on for yourself. Apparently American changed things up from year to year and it is hard to come up with an exact parts manual.
    The original parts manual I have is a work of art for my 44 Model C. Such a pleasure to see such quality especially in our modern days.

  12. #12
    Join Date
    May 2013
    Location
    Shasta County, Ca. USA
    Posts
    1,017
    Post Thanks / Like
    Likes (Given)
    92
    Likes (Received)
    255

    Default

    Hopefully there is someone out there who has reassembled the apron cover and not just those of us who have only taken one off.
    I will post my results for the solution when I get that far.

  13. #13
    Join Date
    May 2013
    Location
    Shasta County, Ca. USA
    Posts
    1,017
    Post Thanks / Like
    Likes (Given)
    92
    Likes (Received)
    255

    Default

    Still hoping someone has put one of these back together and chimes in.

  14. #14
    Join Date
    Jan 2016
    Country
    UNITED STATES
    State/Province
    Vermont
    Posts
    17
    Post Thanks / Like
    Likes (Given)
    3
    Likes (Received)
    0

    Default

    I'm in the same position as apparently everyone else. I'm still in the take-apart stage and although the apron front is restored, I'm working on the apron so haven't got to the reassembly stage yet. I will be following this thread like the others to see if anyone finds a solution and will be sure to post one if I figure it out. Right now I'm having a problem removing the two feed clutches. Anyone removed them and how?

  15. #15
    Join Date
    May 2013
    Location
    Shasta County, Ca. USA
    Posts
    1,017
    Post Thanks / Like
    Likes (Given)
    92
    Likes (Received)
    255

    Default

    Big nut on back of apron holds the feed clutches. As I recall certain gears need to be removed simultaneously on the apron feed side. I remember driving the clutch units out from behind with a brass drift.

  16. #16
    Join Date
    Jan 2016
    Country
    UNITED STATES
    State/Province
    Vermont
    Posts
    17
    Post Thanks / Like
    Likes (Given)
    3
    Likes (Received)
    0

    Default

    Thanks conant. I came to the same conclusion. I'm using an oak 1/2" dowel. When I drive the dowel from the back the front part of the clutch is separating from the back like it's a press fit. This is confusing because it seems like this should be a slip fit to allow the two faces to lock when the handle is engaged. I guess I'll figure it out when I get it separated cleaned and reassembled. Thanks again for your help.

  17. #17
    Join Date
    May 2013
    Location
    Shasta County, Ca. USA
    Posts
    1,017
    Post Thanks / Like
    Likes (Given)
    92
    Likes (Received)
    255

    Default

    Help me remember here. Does the worm gear have to be removed first before the clutch units.
    It is a fixed shaft and the clutching function is a matter of hubs engaging the gear.

  18. #18
    Join Date
    May 2013
    Location
    Shasta County, Ca. USA
    Posts
    1,017
    Post Thanks / Like
    Likes (Given)
    92
    Likes (Received)
    255

    Default

    If you look closely at the pdf that Richard King posted near the top here you will find the diagram showing the feed units.
    After looking closely I see now that the radius in the worm and mating worm gear require removal of the worm before the clutches.
    I do remember that the oil pump needs to be removed so that the worm can pass to the tailstock end and be removed.

  19. #19
    Join Date
    Jan 2016
    Country
    UNITED STATES
    State/Province
    Vermont
    Posts
    17
    Post Thanks / Like
    Likes (Given)
    3
    Likes (Received)
    0

    Default

    I was afraid of that. Hoping I didn't have to mess with the oil pump and oil feed tubing lines. I hope I didn't get this posting to far off topic from my original inquiry. Thanks again, conant for your info.

  20. #20
    Join Date
    May 2013
    Location
    Shasta County, Ca. USA
    Posts
    1,017
    Post Thanks / Like
    Likes (Given)
    92
    Likes (Received)
    255

    Default

    I don't see it being too far off topic. Reason being is there are few out there who have any information on these machines. I scour this forum searching Pratt and Whitney lathe on a regular basis.
    I appreciate finding anything I can.
    The apron and related feed rods and screw are a hand full


Tags for this Thread

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
  •