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View Full Version : Tool post attachment for a die grinder



scottyd
17th Jan 2018, 04:28 PM
Been a while since Ive posted 'round these parts. Last year was flat out with two huge metal projects with students of mine, but more on them another day.

Ive been meaning to make some sort of toolpost grinder setup for my lathe for some time now. Im well aware of the damage abrasives can do to a lathe, but my ole hercus is pretty tired already, so some cylindrical grinding isnt going to ruin a perfectly good machine. What does ruin a perfectly good machine is crappy chucks. The pratt burnerd that came with the lathe was really nice...back in the 70's when it was installed in a school. It has since seen its share of abuse and is quite worn on the tips of the jaws, a typical bell mouth wear. It was an otherwise nice chuck, so I hung onto it for a rainy day and purchased a spiffy 160mm bison chuck.

Fast forward to now and Ive finally got around to the grinder. The long nose maktec grinder (https://ae01.alicdn.com/kf/HTB1l7ZjJpXXXXc5XXXXq6xXFXXXI/Original-Maktec-animal-husbandry-department-straight-mill-grinders-480W-MT912-die-grinders-6mm-bore-the-cartridge.jpg) needed a little "adjustment". I took the nose off the tool, removed the rubber boot and turned the longest part of the nose down to 34mm. The part originally had a taper (a draft angle for the casting) and a sand cast surface finish on this area, making it unsuitable for holding, however there was enough meat on the bone to allow it to be brought down to a parallel and smooth surface.

371667

The adaptor itself is fabricated from a short length of 50 dia 1050 I had kicking around, welded to a length of 50x50 square 1050. Two M16 grub screws were made up from some random mild lying around on my shelf and beneath those is a pair of brass plungers that rest up against the nose of the grinder, securing it in place. The body of the adaptor itself is pretty rough looking at the moment, its got a date with an angle grinder and some paint soon enough. Yesterday I finally got the plungers finished and did a test or two. The first run of the tool was with a pretty badly dressed wheel, not even nearly balanced. Surface finish wasnt too bad, certainly good enough to warrant the tweaking of the wheel. This morning, I acquired a finer wheel, made a half a**ed attempt to dress it. Vibration was muuuuch improved, and so was surface finish. Time to put it to work, out comes the ole pratt burnerd.

Video here! (https://www.youtube.com/watch?v=qAldewCk-h0)

Im -very- happy with it. The surface finish is great. Ive still got a bit more digging to do to get the jaws properly level, the front is still not quite there. Project worth doing!!!

If anyone would like plans, Ive got digital files for all components and ill happily share any details on how to make it.

shootur44
5th Mar 2018, 02:30 AM
Been a while since Ive posted 'round these parts. Last year was flat out with two huge metal projects with students of mine, but more on them another day.

Ive been meaning to make some sort of toolpost grinder setup for my lathe for some time now. Im well aware of the damage abrasives can do to a lathe, but my ole hercus is pretty tired already, so some cylindrical grinding isnt going to ruin a perfectly good machine. What does ruin a perfectly good machine is crappy chucks. The pratt burnerd that came with the lathe was really nice...back in the 70's when it was installed in a school. It has since seen its share of abuse and is quite worn on the tips of the jaws, a typical bell mouth wear. It was an otherwise nice chuck, so I hung onto it for a rainy day and purchased a spiffy 160mm bison chuck.

Fast forward to now and Ive finally got around to the grinder. The long nose maktec grinder (https://ae01.alicdn.com/kf/HTB1l7ZjJpXXXXc5XXXXq6xXFXXXI/Original-Maktec-animal-husbandry-department-straight-mill-grinders-480W-MT912-die-grinders-6mm-bore-the-cartridge.jpg) needed a little "adjustment". I took the nose off the tool, removed the rubber boot and turned the longest part of the nose down to 34mm. The part originally had a taper (a draft angle for the casting) and a sand cast surface finish on this area, making it unsuitable for holding, however there was enough meat on the bone to allow it to be brought down to a parallel and smooth surface.

371667

The adaptor itself is fabricated from a short length of 50 dia 1050 I had kicking around, welded to a length of 50x50 square 1050. Two M16 grub screws were made up from some random mild lying around on my shelf and beneath those is a pair of brass plungers that rest up against the nose of the grinder, securing it in place. The body of the adaptor itself is pretty rough looking at the moment, its got a date with an angle grinder and some paint soon enough. Yesterday I finally got the plungers finished and did a test or two. The first run of the tool was with a pretty badly dressed wheel, not even nearly balanced. Surface finish wasnt too bad, certainly good enough to warrant the tweaking of the wheel. This morning, I acquired a finer wheel, made a half a**ed attempt to dress it. Vibration was muuuuch improved, and so was surface finish. Time to put it to work, out comes the ole pratt burnerd.

Video here! (https://www.youtube.com/watch?v=qAldewCk-h0)

Im -very- happy with it. The surface finish is great. Ive still got a bit more digging to do to get the jaws properly level, the front is still not quite there. Project worth doing!!!

If anyone would like plans, Ive got digital files for all components and ill happily share any details on how to make it.

I would like to get a set of plans if you don’t mind. Thank you for time and plans.


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