Pete.
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- 14,160
- Location
- Kent, UK
I had got a set of DIN6388B collets which go from 2mm - 20mm in 1mm steps and wanted to make a collet chuck to use them. Later I will also make a chuck for my mill and one my tool & cutter grinder but first I made this for my lathe.
I had an old 5" Pratt chuck which was badly bell-mouthed. It was integral Camlock D1-3 so I junked the front half and scroll and used the Camlock rear end as a base for a new collet chuck.
I got a chunk of mystery metal off MattH which turned out to be some kind of alloy steel. It's a bit of a bear to machine but gives a fantastic finish. I also managed to slice a chunk of flesh clean off my finger with the razor-sharp swarf.
Anyway, to the pics. First I took a chunk of unobtanium and faced & turned it to fit nicely in my 4-jaw.
Then I bored out the back of it to fit on the original cast iron backplate, drilled it, bolted it up and stuck it in the lathe on it's own mount. Didn't get any pics of this bit sorry. Once in the lathe I turned the OD and hogged out all the metal to form the nose which filled 3 rubble sacks with deep blue swarf.
Then I bored the 1:10 taper for the collet which took some setting up but when it was done I was very satisfied to find that the collet would fit snugly with a slight tap and have to be tapped out from the rear to release it. It's a good fit.
Then on to the thread. I chose a M36 x 1.5mm thread for the nose. Fine enough to get a good clamp on the collet without too much wrenching on the spanner. As always, I cut the first thread with a black marker to make sure I have the pitch correct.
I had an old 5" Pratt chuck which was badly bell-mouthed. It was integral Camlock D1-3 so I junked the front half and scroll and used the Camlock rear end as a base for a new collet chuck.
I got a chunk of mystery metal off MattH which turned out to be some kind of alloy steel. It's a bit of a bear to machine but gives a fantastic finish. I also managed to slice a chunk of flesh clean off my finger with the razor-sharp swarf.
Anyway, to the pics. First I took a chunk of unobtanium and faced & turned it to fit nicely in my 4-jaw.
Then I bored out the back of it to fit on the original cast iron backplate, drilled it, bolted it up and stuck it in the lathe on it's own mount. Didn't get any pics of this bit sorry. Once in the lathe I turned the OD and hogged out all the metal to form the nose which filled 3 rubble sacks with deep blue swarf.
Then I bored the 1:10 taper for the collet which took some setting up but when it was done I was very satisfied to find that the collet would fit snugly with a slight tap and have to be tapped out from the rear to release it. It's a good fit.
Then on to the thread. I chose a M36 x 1.5mm thread for the nose. Fine enough to get a good clamp on the collet without too much wrenching on the spanner. As always, I cut the first thread with a black marker to make sure I have the pitch correct.