Myford spindle thread

Regards, Tony

DONT forget to relieve the ID.

Mark Rand RTFM

Thanks all. What is this about the ID?

HS

Henry, don't forget the thread only holds the adaptor onto the spindle. It is the surfaces of the register behind the thread that all adaptors, chucks etc use as a reference for concentricity with the mandrel.

The register is 9/16" long and 1 1/4" diameter.

Apologies if I'm providing egg sucking tuition here!

Bob

Henry Spr> Anyone know the thread on ML7 spindle - I can't find the it in the

Make that 7/16 " length for the register -- sorry

Bob

Being a Whitworth form there is a radius at the top and bottom of the thread form. In this instance about 11.5 thou. If you cut the thread with a single point tool you can relieve the ID by 25 thou to avoid binding. If a full form tool is used (12tpi carbide insert or similar) then the radiuses will be made by the tool.

Mark Rand (who felt exceptionally stupid the first time he made a myford mandrel adaptor :-( RTFM

No, I need it! Aactaully the adaptor is so I can use the chucks from the Myford on a smaller lathe with 3/4 thread.

thanks again

HS

Hi Henry, With a relatively large chuck on a small lathe mandrel, you will be turning some distance from the headstock bearing. Light cuts are the order of the day here and I would avoid parting off with this set up.

Also make sure there are some spanner flats on the adaptor (or put some on before you use it). If the adaptor does jam either on the lathe or in the back of the chuck, there is a fair chance of getting it off without having to machine it into swarf! Been there! done it and cursed throughout the process! A trace of grease on the threads, scrupulous cleanliness, and frequent loosening of the threads especially when you have been doing any intermittent cutting (eg on hex or square bar etc) are all sound precautions to avoid tears later

Good luck

Bob