Thread: Installing my 260

It's been a while, but I have been busy

Had to make a back plate for my newly acquired 8" four jaw chuck, I cut the thread on the lathe at work, as mine is metric and doesn't have 11tpi.
I wanted to make it as low profile as possible, so I needed to increase the tool post reach towards the headstock, I made up a new tool post with a second hole, offset to give more reach.
It didn't cause any chatter or vibration so that was a relief, still took 60thou cuts smoothly.

In the future it might come in handy for jobs close to the faceplate

Nice Job Andrew 9
Just as a matter of interest what material is the backing plate made from?
regards
Bruce

Are you sure that thread is 11 tpi,normally they are 8 tpi.
You would need a transposing gear to cut the imperial threads on your lathe.
Didyou think to invert the tool you have and run the lathe in reverse to machine your item.
Looking at the swarf it appears to be blue,I take it that the backing plate is steel rather than cast,if thats the case be careful when it is put on or taken off as the steel with have more tendency to stick due to rusting slightly,seeing it maybe steel it wouldnt hurt to put a little oil on the spindle threads.

Yes, 8tpi I think, I don't really remember as I cut them a month or more ago. I could have bought the gear to cut it, but I don't plan to cut any other imperial threads and the lathe at work was available.

The plate is an old steel hub from a machine, I would have chosen cast iron, but that piece was free!
I use a graphite based "never seize" on my spindle and change chucks at least once every month, so I'm not too worried about it sticking, more worried about possible wear on the spindle because it seems to be a fairly hard piece of steel

My chuck has always come off easy, once I got it unstuck the first time

Running lathe in reverse, on such a large diameter might come unscrewed? (I don't know, never used threaded chuck lathe before this one).
Would that give any more travel?

You can get down past the end of the register with the correct tooling.

A lot of times the compound needs to be at the end of its travel.

I have turned 190 OD material 50 mm thick on a 9" using Carbide and HSS tooling.

Quite often my maching requires me to machine past the end of the register face.

The diameter of the material would have no effect on the chuck unscrewing if the machine was run in reverse,but machining technique would.

All done,
I mounted the chuck with some countersinks into the back plate, so the rear is flat and I can use the front bolts to fit the chuck to my lazy susan.