New toy: Setting up Colchester Student lathe

[M250cnc]

Jonathan i used those machines when i was an apprentice and they were old then as the square headstock models came out so that lathe is at least 45 years old and probably older. It will have not only be used but abused so you should stand back amazed that it is in such good condition.

Re the chuck, small pieces were held and the chucks overtightened so again hardly surprising the jaws are bell mouthed.

You wont be able to SKIM them they need to be ground, obviously you can skim the soft jaws. I would check the fit of the jaw profile in the chuck body worst case a new chuck around £200

Congrats in getting it in.

Phil

[Jonathan]

Jonathan i used those machines when i was an apprentice and they were old then as the square headstock models came out so that lathe is at least 45 years old and probably older. It will have not only be used but abused so you should stand back amazed that it is in such good condition.

The owner said that it had had very little use from him since they've got bigger and better lathes. I tend to believe him since the nut you undo (should be a lever) to rotate the toolpost was extremely hard to undo. I think is the slightly newer version of the old lathe as it's got the later apron and the better bearings.

Re the chuck, small pieces were held and the chucks overtightened so again hardly surprising the jaws are bell mouthed.

You wont be able to SKIM them they need to be ground, obviously you can skim the soft jaws. I would check the fit of the jaw profile in the chuck body worst case a new chuck around £200

Would they be machinable with a carbide tool any plenty of coolant? I read someone doing it on a mini lathe with a diamond tool spinning fast, and the lathe on full speed so the centripetal force pushes the jaws against the thread. That was only to remove a tiny bit though. I guess it's worth a try? Alternatively could I anneal the jaws, machine, then harden again? Just thinking aloud!

I've had the jaws out and there were some burrs on the thread.

Just checked with the indicator and it's the same runout wherever I measure, so must be the chuck at fault. With the indicator on the body of the chuck I get about 0.015mm runout.

Edit:

It's just occured to me, I removed the burrs on the back of the jaws easily enough with a needle file, and somebody's machined them else where which implies that they are machinable. I have a glanze boring bar and some new inserts for it.

[M250cnc]

The owner said that it had had very little use from him since they've got bigger and better lathes. I tend to believe him since the nut you undo (should be a lever) to rotate the toolpost was extremely hard to undo. I think is the slightly newer version of the old lathe as it's got the later apron and the better bearings.

Well he would say that wouldn't he. Not, no mate it's completely flipped.

You can check out the serial number here http://www.lathes.co.uk/colchester/page34.html

Would they be machinable with a carbide tool any plenty of coolant? I read someone doing it on a mini lathe with a diamond tool spinning fast, and the lathe on full speed so the centripetal force pushes the jaws against the thread. That was only to remove a tiny bit though. I guess it's worth a try? Alternatively could I anneal the jaws, machine, then harden again? Just thinking aloud!

Not really, they are ground when made new so there is your answer. Stop thinking out loud don't even think about annealing them

I've had the jaws out and there were some burrs on the thread.

Just checked with the indicator and it's the same runout wherever I measure, so must be the chuck at fault. With the indicator on the body of the chuck I get about 0.015mm runout.

If the runout was repeatable at the same point on the chuck it might be worth it, but if the run out changes position then you live with it or buy a new chuck.

Phil

[Jonathan]

Well he would say that wouldn't he. Not, no mate it's completely flipped. You can check out the serial number here http://www.lathes.co.uk/colchester/page34.html

Yes, of course he would. He didn't realise the 4 jaw chuck was in the cabinate until he started shifting the lathe, so I got that chuck for nothing. I'll check the number tomorrow.

If the runout was repeatable at the same point on the chuck it might be worth it, but if the run out changes position then you live with it

Sorry I'm not sure what you mean by 'at the same point'?

[Jonathan]

The machine No. is F 2/65795 - I think that's 1968 so not too bad considering they stopped making them in 1972. Still more than twice as old as me :lol: