Announcement

Collapse
No announcement yet.

Ugh, setscrew on threads???!

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Ugh, setscrew on threads???!

    Ok, I started working on the opposite end of the spindle. I got a collar to move, but not far. Peering into the set screw hole, I see this:



    So, what do I do? I can't get the collar off... by twisting it...

  • #2
    Dimple it with a drill and when you replace it use a copper pad at the bottom of the hole and a cup screw, not a pointed screw [ or just grind the point off ]

    .
    .

    Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



    Comment


    • #3
      Looks like the back end of an Atlas lathe spindle. There's supposed to be a lead plug protecting the threads, but any other soft metal will do. Wad up some solder, works fine.

      Joe

      Comment


      • #4
        Hi,

        Pretty common cheap method to lock a collar to the shaft. I do it all the time at work .

        The photo doesn't look too bad, I've seen worse. You stand a better chance of getting it off if you have a pin spanner wrench. One like this should do the job, [URL=http://www.grainger.com/Grainger/items/1FJ44[/URL]

        They aren't cheap, but they do work well.

        dalee
        Last edited by dalee100; 11-11-2007, 07:12 PM.
        If you think you understand what is going on, you haven't been paying attention.

        Comment


        • #5
          Damaged threads

          Screw a bolt into the hole as a wrench but not against the threads.
          Turn the collar until it starts to bind and tap it in all directions with a
          small hammer. Loosen the collar and repeat. The hope is to hammer the burr
          back down and not destroy the collar threads. This works quite well
          much of the time. Best regards, Charlie
          Last edited by Charles Lessig; 11-11-2007, 07:36 PM.

          Comment


          • #6
            How about grinding a 60 degree V on the end of a small rod (old drill ?) and using it to deform/reform the dimpled area so the collar will unscrew.

            Glenn

            Comment


            • #7
              Tony, Grab a big pipe wrench if you have to for that collar. If you mar it then just re turn it to make it beautiful. It's just a threaded collar.
              The threads will be very easy to restore with just a threading file if they burr up a tad during removal. Squirt a little oil into the threads beforehand.
              And , you have to impact that chuck off. You are only dealing with a threaded nut in reality. Unless it has truly rusted tight it will come off with a very hard sharp rap by hand. No wood! Wood will absorb away all the impact.
              I'll tell you what, this old artisan lathe with it's 2" 8tpi thread locks the chuck TIGHT as the face register fit is so good!. I can apply enough force by leverage alone to tip the near 400lb machine over before the chuck will even come close to breaking loose after just spinning it on by hand. But a sharp hard rap and it's loose instantly.
              I have wrenched on cars for near 30 years. There is a definite skill to hand impacting. It's not about taking a 15lb sledge and following through like you want to destroy something. It's almost a wrist action type blow.
              I wish you were local so I could help but best of luck as I want to see your machine restored!
              Steve

              Comment


              • #8
                My lathe spindle rear collar/nut was like that. I thought I would never get it off. When I did, I fixed the threads, but the Royal collet dog has to be locked on by that screw. So I did what I've done before and since. I took a piece of solid copper wire from a short scrap of 10-2 house wiring. Cut off a piece about 3/16 long, bent it about 90*, used a vice to fold it on down and sorta shape into a hocky puck, then put that beneath the grub screw. Had to take it apart again not too long ago. The collar scewed right off, a bit "stiff" to start, but that was from the copper deformed into the threads. It worked loose(ish) in about 1 turn and came off with no damaged threads.
                Russ
                Master Floor Sweeper

                Comment


                • #9
                  I've used lead shot many times under those type setscrews.
                  I have tools I don't even know I own...

                  Comment


                  • #10
                    Don't go and bull moose the collar nut off with pipe wrenches. What's wrong with you guys offering advice like that? You watch too many Schwartzenegger movies. You'll damage the threads; quite possibly ruining them.

                    There's a better, gentler way one that uses intelligence and craft instead of raw brawn: put the deformed metal back where it came from.

                    Make up a little narrow cold chisel and use it with a light hammer to reach in and restore the damaged threads to form again by wedging them without actually cutting anything. Test the nut from time to time using the contact burnish to detect which raised surface need a little more attention. Be sure the exposed threads and are clean and you use plenty of extreme pressure oil (I like worm gear oil) when you unscrew the nut. If you meet gritty resistance stop instantly and cycle the nut gently to resistance and back. Sooner or later you'll get past the resistance without galling the metal. A good mechanic works wiithout unnecessary drama or causing damage to the parts.

                    Use a dog point or a cup point set screw to replace the pointy screw you have. Use annealed copper or a lead shot between the thread and the screw. A soft solder blob works fine too.
                    Last edited by Forrest Addy; 11-12-2007, 02:01 PM.

                    Comment


                    • #11
                      Think wider

                      Most of the methods suggested for re-placing the nut are only variations of the method that caused the problem in the first place.

                      An old old method of making a "shake-resistant" (as opposed to a "shake-proof") nut is to cut/saw it half way through at right angles to the thread and then compress or close the gap made by the cut in one of several ways:
                      - close it in a vice until it "sets";
                      - hit it with a brass/bronze "dolly";
                      - drill the outer part to be a clearance fit on a selected thread, drill and tap the inner part, fit hex or socket-head screw and shake-resistant washer, fit modified collar onto its original thread on (lathe?) spindle to required "torque", tighten socket/hex screw to suit.

                      To remove, just slacken off tightening screw and use "C" spanner or similar.

                      And no more need for the original problem screw or risk of damage to the spindle thread.

                      These methods are "oldies" but they work!!!

                      Comment


                      • #12
                        Don't go and bull moose the collar nut off with pipe wrenches. What's wrong with you guys offering advice like that? You watch too many Schwartzenegger movies. You'll damage the threads; quite possibly ruining them.

                        There's a better, gentler way one that uses intelligence and craft instead of stupidity and brawn: put the deformed metal back where it came from.
                        Forest, Perhaps you are right to advise as you did. But please do not call my methods stupid. Machining is relatively new to me but not wrenching and fabrication!
                        But I guess I have to agree if one is new to this type of situation then a little more careful method as you suggested is in order.
                        Steve

                        Comment


                        • #13
                          S J H. My words were never meant to ridicule but to shock and cause reassessment. However you were correct in taking exception. I was unneceessarily offensive so I amended my post.

                          Here's your original words: "Tony, Grab a big pipe wrench if you have to for that collar. If you mar it then just re turn it to make it beautiful. It's just a threaded collar.

                          "The threads will be very easy to restore with just a threading file if they burr up a tad during removal. Squirt a little oil into the threads beforehand."

                          Please don't be upset with my lack of concurrance but I'd never reccommend a pipe wrench on a retainer nut except in the last extremety. Why risk damaging the threads in the first place? It's hard to reconcile your advice with damage free-disassembly possible with widely used methods. With a little care and technique, you don't need to risk damaging the threads or marring the nut. My words are but echoes passed to me by my mentors years ago. They are as apt today as they were then: there's no need to cause further damage with disassembly methind and adding to the work of repair if a little care can accomplish the task without damage.

                          In your post you go on to illustrate the proper use of a heavy hammer in dissassembly of precison made machinery. I prefer to use the word "nudge" in this connection but your words suggest the care necessary when using a big hammer to pursuade the movement of tightly fitted parts. I've used a big hammer in just such a way many times. One of my favorite mantras is "you can do more damage with a little hammer than a big one."

                          Comment


                          • #14
                            Being a startup shop, I don't have a lot of tools capable of reaching into the small set-screw hole. I did have a small Craftsman screwdriver. I put it into the threads, pushed hard, and turned the collar. Repeatedly. This improved the threads. Finally with some force I was able to get the collar off. The spindle threads look ok.

                            Now there's the back gear. This is also threaded on, and held secure with a key. The key isn't a tight fit at all, but it seems captured. The gear turns a little before so it shouldn't be hard to get off once the key's out. The key is tricksie, I haven't figured out how to remove it. It's in a mating slot on the spindle and a slot on the gear, but neither slot seems large enough to accept the entire key and allow the spindle to turn.

                            But I'm not in the mood to fool with it tonight.

                            Comment


                            • #15
                              Never mind, you were too fast for my reply.

                              Comment

                              Working...
                              X