Hi all,

Bought a new 4 jaw sc chuck in the new year and am in the process of machiningthe backplate. Both sides faced and bored to slip over the headstock spindle. All holes drilled and tapped or counter bored for the chuck bolts. So far so good. Come to turn down the OD and realise the carriage won't travel close enoughto the headstock. Need a minimum of 40mm more travel.

I have a qctp fitted which gives a bit more overhang than the standard toolpost and the compound slide is extended as far as possible.

It appears the carriage is very near to the end of the leadscrew and that limits the travel. Anybody else come up against this problem and how did you overcome it ?

Tia

Brian

Hi Rik

Tried using a carbide tip boring tool upside down with the lathe in reverse. Not pleasant finish very poor. I wanted to try what you suggest but only have a small r / h knife tool. I do have some 12mm hss blanks so might make one.

Will see if taking the leadscrew out will work first

Finished off the backplate today using upside down boring bar. Finished the OD with emery to polish out the chatter marks. The register was cut withe the same tool + new tip and turned out okay a (good fit any way).

Still feels like i bodged it a bit though.

Thanks to all