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  • Lead pour release

    The 10" wheel on my grinder has been out of side to side balance since new so today I finally got fed up and pulled it off. Instead of a center bushing for the shaft it has a poured lead bushing. Pretty rough too. So I punched it out and machined up a Teflon one but as you might expect that didn't work. So I am planning on setting it up with a 3/4 steel (?) plug and pouring new lead around it but I am wondering if I will be able to get the plug out without damage. Pretty thin wall of about 1/16. Any suggestions on this idea? Cheers!

  • #2
    Are you saying the lead will be 1/16th thick? Lead shrinks a lot when solidifying so as long as it doesn't bond (as in solder bond) to the steel the bushing should press out fine.
    Southwest Utah

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    • #3
      Could always spray it with PAM cooking spray. No kidding, as a welder I use that stuff for an anti-spatter. It makes a good mold release too, I used to cast my fishing weights with it.

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      • #4
        So you're pouring it into the center of the wheel? What's keeping your mandrill centered? If it were me I would make a delrin bushing with a slightly oversized OD, press it in, then ream it out. The tension of the springy delrin should hold it.
        Location: Jersey City NJ USA

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        • #5
          Originally posted by chipmaker4130 View Post
          Are you saying the lead will be 1/16th thick? Lead shrinks a lot when solidifying so as long as it doesn't bond (as in solder bond) to the steel the bushing should press out fine.
          Yes wall thickness of the poured bushing is about 1/16".

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          • #6
            Originally posted by gellfex View Post
            So you're pouring it into the center of the wheel? What's keeping your mandrill centered? If it were me I would make a delrin bushing with a slightly oversized OD, press it in, then ream it out. The tension of the springy delrin should hold it.
            I tried that with a nylon/teflon bushing problem is the hold in the wheel is not correct making anything you turn transfer the wobble. Thats why I think they used lead. I will center the mandrill in the hole and then dress the wheel after the fact. Its the side to side wobble I need to correct.

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            • #7
              delrin is what i have done. not easy. because you have to let it stabilize after machining. i did several, so it was worth the effort. many old wheels come filled with some kind of plaster, so you might do that as well, using compensated grout perhaps.

              vector, its the flanges giving you the wobble, right?
              Last edited by dian; 03-04-2020, 11:34 PM.

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              • #8
                Originally posted by vectorwarbirds View Post

                I tried that with a nylon/teflon bushing problem is the hold in the wheel is not correct making anything you turn transfer the wobble. Thats why I think they used lead. I will center the mandrill in the hole and then dress the wheel after the fact. Its the side to side wobble I need to correct.
                That's why you undesize the hole and ream it square and true on the drill press.

                dian can you elaborate on "stabilizing" delrin? I've used it all the time for 30 years but know nothing about that. However I was not taught by real machinists.
                Location: Jersey City NJ USA

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                • #9
                  well, maybe that can be done, no idea. i was saying: let it stabilize. it would move for several days. so what i ended up doing is to bring it to certain dimension in the freezer, machine and wait 3 days to check the final fit. i wont be making any sliding fits on any plastic parts very soon.

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                  • #10
                    I have used lead when fitting a new shaft to a big old grindstone. This was an old type made from real stone, about 2 foot diameter x 4 inches wide. Lead was what they used originally as there was a square hole in the wheel and a smaller shaft.

                    I poured the lead, but I think I might have seen lead thread used too.

                    The thing is you have to then do the wheel truing and dressing afterwards.

                    In this case, the wheel outside diameter was not just running out, but had high and low points.

                    I set up a steel guide (clamped to the frame) and then used a carbide tool from the lathe and ran it back and forth across the wheel face. Move the guide as required. No need to use a new insert! Best done outside...

                    True the sides of the wheel too, from the OD, back to the flanges.

                    I don't think you will be able to get it right without truing/dressing the wheel after fitting it to the shaft.


                    If the hole in the grinding wheel is round, then I don't see why a plastic bush won't work. That's pretty standard for bench grinders.

                    Forget about a precision, reamed, stabilized bush etc. They are not supposed to be tight.

                    I reckon the wheel flanges are supposed to do the clamping, and they shouldn't be prevented from clamping properly by a tight, inflexible bush. Presumably the hole is not square to the sides, or the sides are not parallel.

                    Use thick paper washers between the flanges and the wheel.

                    True the wheel afterwards.


                    Another thought, if there is side to side wobble, it could be a badly made wheel (get a new one). Also check the grinder shaft is not bent.


                    Last edited by Peter S; 03-05-2020, 12:28 AM.

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                    • #11
                      Originally posted by Peter S View Post
                      ...
                      Another thought, if there is side to side wobble, it could be a badly made wheel (get a new one). Also check the grinder shaft is not bent.
                      Yeah ... I don't see how the hole can affect the wobble-ness. The flanges hold it true - the hole just centers it. Bad wheel, bent shaft, wonky flanges. Do any other wheels wobble on this grinder?

                      Put the wheel on an arbor in your lathe & check out-of-flatness. Or on a surface plate, should you have one.

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                      • #12
                        Only this wheel has a problem, shaft runs true. The hole in the wheel is wonky, not true. I am going to check the flanges but suspect they are fine as this is the only wheel that does this. Don't want to buy a new wheel want to fix this one. Maybe best to diamond dress the sides instead but then have to buy that. Going to recheck the bushing I made and give it a little more clearance to see if the flanges pull it straight. Rather soft bushing so probably not that. Some good advice thanks.

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                        • #13
                          It was common to use carbon from a cutting torch to coat a shaft to prevent sticking when pouring babbit. Set mixture with no oxygen to get black smoke.

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                          • #14
                            Originally posted by deltap View Post
                            It was common to use carbon from a cutting torch to coat a shaft to prevent sticking when pouring babbit. Set mixture with no oxygen to get black smoke.
                            Thanks Deltap just what I was looking for! And its free!

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                            • #15
                              This is getting complicated
                              How about greasing your drill press table ( or put wax paper on it)
                              Center your wheel flat on the table and concentric to the spindle
                              Chuck a 1/2" greased rod in the chuck, and then fill the hole with JB Weld and introduce the round rod into the hold
                              Let it harden , withdraw the rod and scrape off the excess, and then mount the wheel
                              The lead is to squelch the vibrations, but the JB weld will also try to do the same
                              Rich
                              Green Bay, WI

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