Hole in tool post

Yep.

But my 4 jaw won't reach, it's too small.
Sad.

The alignment of the toolpost matters most if you are using a parting off tool which must be at right angles to the spindle axis. For most home use having exact location is optional as long as the toolpost can be tightened securely.

John Haine's toolpost mod is the neatest and stiffest that I have seen, and it can be removed quickly if the compound is needed for a specific job.

Faceplates.. ..Just on the off-chance, you might as well give us the the spindle nose / flange dimensions.. ..even if nothing used turns up, you might at least find out if something new can still be obtained..?

The hole in question has often had a pin with a knurled end on some of the lathes I have encountered. If using it as a setting aid then the fit of the tool post to the fixing bolt will need to be checked.

Mike

The chuck mounting is a bit of a pain.
It's not a screw-on type, but has a mounting plate already on the end of the shaft.
Changing chucks involves undoing three socket head screws with only a thin space to get in to them. Even the Allen key has to have a short end.

I think I might be on the way.
From a piece of ½" steel plate from the centre plate of a Purbrook Heron (don't ask), I've managed to make a 'sort-of' faceplate.
Took a lot of hacking and angle grinding.
But with four holes in it each big enough to take the 'tip' of the four jaw jaws, if you follow me, then drill a hole in the middle as big as the largest drill I have, and bore out to about 1 ¾" so it can be mounted in the three jaw and faced off etc.

So now I've got a 7" faceplate that mounts in the four jaw chuck, and can be jiggled to get the flywheel running true to the inside edge of the rim.
All it needs now is drill and tap some holes in it for clamping bolts for the flywheel.

And take things very carefully.

And I thought that you were going to make a faceplate for your lathe.

If you find the the Allen screws are a PITA, why not make nuts with a reduced shank (to fit into the counterbores ) and use studs instead of the Allen screws.

The choice of spanner to use, or the size of hexagon, is up to you.

Howard.

Well I could of course.
But making a 'proper' faceplate would encounter the same problems with the size of chuck.
Have to hold it somehow to turn the locating recess.

Plenty of mods to make for the lathe, including your suggestion.
But at the moment I just want to get this flywheel done.

And I am saving for a better lathe, as this one is shall we say 'past it'.

This is my setup with a Bison QC toolpost and a rigid mount replacing the topslide. The hole is used for an extra M6 bolt to prevent movement.

That looks good.

If only I could do away with the topslide I might do something similar.
But, as I said, the main saddle hand wheel is way to fast and 'clunky' to use for anything serious.
Maybe on my next lathe ......

Wow, 2 pictures of a properly thought out replacement for the compound slide in one thread, Ifoggy has one too!

This is my mod to my lathe with the compound removed. It's an old photo so does not show all the features. I removed the compound and fitted a T slot plate (3 slots) on top of the cross slide. Between the T plate and the tool holder block is an intermediate plate with machined in tenons that fit snugly into the slots. The tool post was aligned with the spindle centre of rotation, clamped down, rechecked for alignment then a drill was used through the index hole to drill into the intermediate block about 6mm (plus the cone from the drill tip). I turned a snug fitting pin with a small taper on the tip and a knurled top.

I can remove the T slot plate and refit the compound and 4 way tool post if I ever feel the need to.

Martin C

That's a nice mod Martin.

Unfortunately I can't do away with the topslide.
The main saddle wheel is very course, one division is half a mm, so trying to take a few thou off something really needs the topslide, where one div is 0.05mm.
And it's an old BV20 lathe with no DRO or anything fancy like that.

4 jaw not big enough to get to the rim.

Reverse the jaws and grip from the inside?

Yep.
Standard procedure.
Still too small.

Won't reach.

OK, to be fair, I've just tried it again, and it is possible, just. But VERY dodgy. Literally another quarter turn on the key and the jaw falls out.

Anyway, done the job now with a plate and bolts to hold the flywheel, the plate having four holes in it to take the 4 jaw jaws.

Other problems with this is, 4 jaws and 6 spokes.
Nothing to locate against.