Finding a chuck for old Sherline wood lathe. 9/16 12 Whitworth.

[graduate_owner]

It is a difficult decision - is it better to keep the lathe and spend out on accessories, or to cut losses and get a better lathe? Perhaps the compromise would be to keep the lathe (for now, until the limitations become too much to tolerate) but buy accessories that can be used on a replacement machine, - chuck via an adaptor for example. I think I would buy a chuck with a 'standard' thread (if only there was such a thing) such as M33 or 1" x 8tpi, and an adapter for the existing lathe. Then the chuck and jaws can be kept and used - they will probably cost far more than the lathe anyway, certainly far more than the value os this particular lathe.

No offence intended to OP but these lathes really are dire.

K

 

[dizjasta]

It is a difficult decision - is it better to keep the lathe and spend out on accessories, or to cut losses and get a better lathe? Perhaps the compromise would be to keep the lathe (for now, until the limitations become too much to tolerate) but buy accessories that can be used on a replacement machine, - chuck via an adaptor for example. I think I would buy a chuck with a 'standard' thread (if only there was such a thing) such as M33 or 1" x 8tpi, and an adapter for the existing lathe. Then the chuck and jaws can be kept and used - they will probably cost far more than the lathe anyway, certainly far more than the value os this particular lathe.

No offence intended to OP but these lathes really are dire.

K

The Sherline lathe was a gift to Keith.

 

[Keith in Dorset]

This may get me started. Much appreciated.

Hi again. I have reviewed the various options. Do I understand correctly that the first option would be to ‘simply’ re-thread the Unimat SL M12 1 chuck hole directly with a 9/16th 12 (BSW) tap? If so would I need an especially hardened tap or other specialised set up? Many thanks. Keith.

It is not a great solution, but it might be an option:

The Unimat SL has an M12 x 1 spindle thread. The tapping drill size for 9/16" BSW is 12mm. You could buy a chuck or backplate for the Unimat SL (e.g. https://www.chronos.ltd.uk/product/soba-4-jaw-self-centering-chuck-50-mm-dia-m12-thread/) and modify to suit.

Modern Unimat uses M14 spindle threads and modern Sherline and Taig (and many other modern wood lathes) use 3/4" UNF so an an adaptor with 9/16 BSW internal and one of those external threads might make the machine usable again (3/4" UNF tapping drill is 11/16" so adaptor would have 1/16" wall thickness).

It has been mentioned here before: there is a company called Beaufort Ink who might make you custom adaptor.

I appreciate you do not want a review of the lathe, but might I suggest you do not go spending out on extras for this one. It has very poor reviews and I am sure you will want to upgrade from there, so I would repeat previous comments - get a better lathe and buy the extras for that. If money is tight, don't throw good money after bad. And if you take to turning as hobby, you will want to enjoy it, not tolerate it.

K

Hi. I do appreciate your and others’ comments about the efficiency of this lathe compared to better models. I was given this lathe for free, and have since inherited more turning gouges. My main hobby is effectively getting old tools ‘restored’ i.e. up and running, and I only turn the odd spindle from time to time. I have managed to date turning bits and pieces between centres, but have from time to time come across jobs where a chuck would have been useful. I am in the fortunate position of being able to purchase a better lathe, and accessories, however for the time being at least, (and having had only a passing interest in wood turning for fifty years), honestly do not have the inclination to take things further. Thanks again for the very sound advice re. finances that I do not intend to ignore.

 

[HOJ]

@Keith in Dorset I bet my Nu tool lathe is, in comparison, "worse" than your Sherline, but in the face of adversity I've managed for getting on for 30 years to turn all the things I've ever needed, also got a little Clarke 13" thing that I use (gifted) which has also served me well.

 

[Robbo3]

If you can find a tap to match your headstock thread at least you could make your own wooden faceplates & jamb chucks. That would give you more scope than you presently have.

 

[ChaiLatte]

If you can find a tap to match your headstock thread at least you could make your own wooden faceplates

The wooden prototype is a very good idea.

The spindle thread appears quite long and has a plain register on it that ensures the screwed-on item runs true. Making a wooden one would show you what is necessary to make a metal chuck fit and if it goes wrong, it is no great loss.

With any potential metal chuck, the OP would need to check there was enough 'meat' on it to accommodate the required 9/16" thread. The length of thread plus register is quite long (appears to be approx. 30mm - 20mm thread plus 10mm register) so the body depth of any metal chuck would have to accommodate this without the outboard end of the spindle impeding the chuck jaws closing.

It is not easy to obtain the needed dimensions of the potential chuck without actually buying it, so it is a conundrum.

 

[Duncan A]

The picture may be misleading, but the unthreaded portion of the spindle looks as if it is a greater diameter than the thread. If so, it may be best to have a sleeve made to screw onto the spindle and with an external thread to suit a "standard" chuck thread.
Since the OP has made it clear that he is not intending to turn 400mm bowls or to engineering standards of accuracy, pretty well any chuck would do the job e.g. https://uk.vevor.com/lathe-chuck-c_...erm=4587437398458153&utm_content=All Products
or, better,
https://www.quality-woodworking-too...-scroll-chuck-set-95-mm-1-x-8-tpi-m33-thread/
This latter one would cover the two common thread standards at modest cost whilst leaving the door open to additional jaws if wanted in the future.
Duncan

 

[Keith in Dorset]

If you can find a tap to match your headstock thread at least you could make your own wooden faceplates & jamb chucks. That would give you more scope than you presently have.

Thanks Robbo, I do already have a face plate with the correct thread that is fine.

 

[Wildman]

Thank you. I have only measured the thread with a Moore & Wright gauge that is marked ‘WHIT’ on the outer casing … so that’s why I have gone for this. It fits 9/16 12 perfectly so far as I can see. I don’t know anything about the difference between UNC and BSW, without Googling, to know if there could be much of a problem here, so I appreciate your caution. I always use metric now when I get the chance.

the difference is in the thread angle 55 or 60 deg