Advice Wanted - On obtaining help...

Andy

I believe you need to have a better spec material than mild steel for a spindle, as a minimum EN8 but En16 or higher would be my choice.

Emgee

If you want replacement chucks, why not make an adaptor?

I've made one to fit Myford 7 Series thread (1.125 x 12 tpi ) chucks to a Myford ML4.

Also, more recently, have modified a backplate to allow a modern 80 mm chuck (Intended for a mini lathe ) to be screwed onto a 3/4 x 10 tpi Whit form threaded mandrel on a much older lathe.

An adaptor might well be cheaper abd quisker than a complete new spindle.

Howard.

It seems my post has probably come across as, at best very naive and at worst careless and completely lacking any forethought!

In fact I've been pondering the problem for a few weeks and done quite a bit of research in various places, these forums included, where others have encountered the sample "problem" with exactly the same lathe (and its close cousins).

Many options have been considered by others (with lots of input from forum members). I obviously won't repeat all the options and the arguments for discounting them (including a spindle adapter) here but in summary there have been two solutions used by others that stand out:

1) Manufacture a new spindle.

2) Bore out the chuck and convert, and insert a bush threaded to suit the existing spindle (effectively an adapter in the chuck rather than on the spindle). Down side of this of course is it has to be repeated for each check or accessory to be mounted on the spindle.

and actually, none of these solutions is feasible without a usable chuck to hold the work in. That, you might say, is the chicken-and-egg situation I have here

Andy

If you go for a backplate fitting chuck then once the thread has been cut in the backplate which could be done with drill press and tap then the remaining machining is done in situe so does not need a chuck to hold the backplate. A backplate mount chuck also needs no modification. May lessen your chuck choice a bit in the smaller sizes which tend to more commonly come with a threaded body. What diameter chuck were you looking to fit?

Jason clarifies what I was suggesting.

Make an adaptor to go onto the spindle, (It can stay there ) that wil accept the chuck(s ) that you want to fit.

This is the easier way. The adaptor effectgively changes the spindle nose to one that suits the chuck(s ) you wish to use.

Take look at the latest post in My Albums, to see one that I made to fit 7 Series Myford thread chucks to a Myford ML4.

For another lathe, lacking a specific backplate, a backplate was modified and fitted to that particular chuck.

The lathe then had a choice of the original 3 jaw chuck, or a modern 80mm 4 jaw, (intended for a mini lathe ), but now fitting a 3/4 x 10 Whit form spindle.

In both cases the original spindle and its internal taper are preserved..

Having made and fitted the adaptor to the spindle, leave it place and mount the backplate for any other chuck on it to face it and turn the OD and register before fitting to the chuck.

Howard