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Ideas for removing small tight (maybe locktited) pins from cast iron table?

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  • #16
    At some point, I will post a thread about some work I've been doing to one of my Bridgeports but one of the tips I was going to share is for just this kind of situation.

    Instead of trying to TIG weld an extension onto the pin, put an 1/8" collet in the TIG torch and clamp onto a piece of 1/8" filler rod. No worries about spatter with the cast iron and all you have to do is get a small arc started and then dip the filler into the puddle while letting off the trigger. You just fuse the two together similar to a stud welder. Then remove the torch and pull on the filler rod with slide hammer, etc. to remove the stuck bit. Very little heat involved but probably just enough to loosen any Loctite. Works really well for pins that are broke off below the surface and / or are too small to TIG a stub to in the ordinary way.

    Assumes you have access to a TIG welder, of course.

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    • #17
      Hi,

      Since there is no reason the holes must be located in their original positions, I would recommend that you simply drill new holes in a different location and simply forget you ever saw the cut off pins.
      If you think you understand what is going on, you haven't been paying attention.

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      • #18
        Originally posted by Fasttrack View Post
        At some point, I will post a thread about some work I've been doing to one of my Bridgeports but one of the tips I was going to share is for just this kind of situation.

        Instead of trying to TIG weld an extension onto the pin, put an 1/8" collet in the TIG torch and clamp onto a piece of 1/8" filler rod. No worries about spatter with the cast iron and all you have to do is get a small arc started and then dip the filler into the puddle while letting off the trigger. You just fuse the two together similar to a stud welder. Then remove the torch and pull on the filler rod with slide hammer, etc. to remove the stuck bit. Very little heat involved but probably just enough to loosen any Loctite. Works really well for pins that are broke off below the surface and / or are too small to TIG a stub to in the ordinary way.

        Assumes you have access to a TIG welder, of course.
        I have a TIG and that is a fantastic idea ! I will have to remember that one! Thanks !

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        • #19
          The pins are probably in the same place on both ends. Maybe you could use the good end to make a drill jig with the correct pin locations, transfer it to the other end and drill them out, or drill and tap and use a bolt through a socket to pull them.
          Kansas City area

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          • #20
            Originally posted by 754 View Post
            .....................

            The original end plate with reducer sleeve in hole, will that nit guide the drill ?
            An excellent idea, but what aligns the plate? The bolt holes are large. I would be guesstimating centrality just as much as if I put in a center pop and drilled using that.

            Given that the previous owner, or whoever did it, already had the pins sticking out, and the PO had a welder, one wonders why they opted to cut off and not weld to them and pull. Could have been lazy or stupid, might have tried and failed, dunno.

            It looks as if the "original gorilla" sawed them off, and then possibly punched them down to just barely below flush, since there are few if any saw marks on the face. If so, I might punch them farther, and use the exposed hole as a guide. At the moment, I cannot go visit the welder, and there is no tig anyhow, although I do like tig welding better than the other types.
            3751 6193 2700 3517

            Keep eye on ball.
            Hashim Khan

            If you look closely at a digital signal, you find out it is really analog......

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            • #21
              EDM

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              • #22
                JT there is 2 bolt holes on end plate right.. eyeball pin thru hole using a strong lite , then tighten bolts . Then sleeve and drill ..repeat on end hole .
                Can be done with table on machine, sit on a chair or bucket.
                once you have a tiny hole drilled in center, it gets easier..

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                • #23
                  I ran into a slightly similar situation at a place I worked one time. Two broken off 3/16" dowel pins, both broken off below flush. The part they were in was attached to a larger assembly and while it could have been removed and the pins removed on a milling machine or drill press, doing so would require a lengthy and complex realignment of the equipment involved and was strictly a very last resort.

                  The first try was to use an alignment jig with a drill bushing to try to drill the pins out. Should have worked but the they were only able to drill a short way into the pin before it hit was seemed to be a very hard core in the pins. Any attempt to drill further just messed up the drill bits. Tried "hard material" bits, carbide, etc to no success. I suspect it was the small size of the bits and the fact that you could not get enough pressure on it using a handheld drill just made it a no-go.

                  I finally ended up just gnawing away at the pins with a series of carbide burrs just a bit larger than dental burrs. I was able to essentially grind the pins away mostly to dust and just pick out the few larger pieces. Wore out a fair number of burrs. Tedious and slow as can be, but got them out with little to no damage to the holes.

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                  • #24
                    Center punch each pin on center, start a 1/16" drill into the ends about 1/8" deep. Make up a drill guide block for a #29 drill, stick the #29 drill through the block and feel out the location of the 1/16" pilot with the #29 drill tip. Clamp the guide in place and drill the pin through. Tap the pin 8/32, lop off a fully threaded 8/32 socket head capscrew to use as a stud. Find a nut, washer and sleeve to jack the pin out.
                    I just need one more tool,just one!

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                    • #25
                      That was one I considered, figuring the largest stud possible to get into the pin would be the best. The stud has to be strong enough to pull the tight pin out.

                      So far that also seems to have the fewest issues even if the attempt fails, since there is a hole, and a fairly soft stud in it which can be drilled out again.

                      Plus there is always the chance that the drilling will just loosen the pin up if it is not so tight, but just held in mostly with loctite. I've had the removal of the middle heat up stuck items enough to break the loctite, or just loosen enough to be pulled or "dug" out of there.

                      The hole probably will not be in the middle, but it may not matter. Won't matter at all if it does pull. Almost all the other methods have the same drawback of not getting the hole centered.

                      I'm generally cleaning up the shop, and may get to give removal a try tonight. I am staying away from the kitchen, my wife is cooking up a storm even though we are not having anyone over. If I am cleaning up then I am not "sitting on my ass", and all is well. (I think the ultimate plan is that neighbors get goodies, )
                      3751 6193 2700 3517

                      Keep eye on ball.
                      Hashim Khan

                      If you look closely at a digital signal, you find out it is really analog......

                      Comment


                      • #26
                        If you're going to drill it, use a left-hand drill. It'll drill just as well as a RH drill and you might be pleasantly surprised.

                        -js
                        There are no stupid questions. But there are lots of stupid answers. This is the internet.

                        Location: SF Bay Area

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                        • #27
                          How many capacitors do you have around- charge up an array and use that to zap a pull rod onto the remains of the pin.
                          I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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                          • #28
                            The holes are now clear, I will cut some pins and install them.

                            You will never guess what worked just fine.......
                            3751 6193 2700 3517

                            Keep eye on ball.
                            Hashim Khan

                            If you look closely at a digital signal, you find out it is really analog......

                            Comment


                            • #29
                              Originally posted by J Tiers View Post
                              The holes are now clear, I will cut some pins and install them.

                              You will never guess what worked just fine.......
                              No, no, no, you are doing it wrong. You are supposed to say something like: "I tried 12 things to get these pins out. Number 7 will AMAZE you!!!"

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                              • #30
                                Originally posted by J Tiers View Post
                                The holes are now clear, I will cut some pins and install them.

                                You will never guess what worked just fine.......
                                You Crazy Glued a rod to them and pulled them out?
                                Location: Saskatoon, Saskatchewan, Canada

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