Searching 4-jaw lathe chuck with dovetail jaws for M16x1.5 spindle thread

[Oliver Hoffinger]

Dear forum,
I am searching for a method to roughly work on wood on my miniature lathe.
It has an unconventional sizing, I've read so at least, with a M16 spindle threading (? not an English speaker, I hope I am using terminology correctly).
To work on wood safely, I would like a 4 jaw chuck on which I can mount dovetail jaws.
While these chucks are available for M33, I cannot find them for M16.
Is there a website that sells them which I have not been able to find?

I would appreciate help, even if it's just a very quick answer.
Best regards,
Oliver

[druxey]

Here is one source:

 

https://www.chippingaway.com/shop/miniature-tools-wood-working/proxxon-bench-top-power-tools/proxxon-micro-woodturning-lathe/4-jaw-chuck/

 

There are others if you search the Internet.

[DavidG]

I have one of these. It's made of plastic and not self-centering, the jaws must be adjusted one by one by plastic screws. I didn't find much use of it.

[druxey]

Ouch! I had not read the description of that particular chuck in detail. I would shy away from plastic as well! 

[bruce d]

3 hours ago, DavidG said:

I have one of these. It's made of plastic and not self-centering, the jaws must be adjusted one by one by plastic screws. I didn't find much use of it.

I bought one a few years ago and was shocked when a plastic chuck arrived: sent it back and bluntly told them to add that detail to the description.

Having said that, it probably has a use somewhere, just not in my shop.  They are currently available on Ebay in the UK for £22.  

[BANYAN]

Not 100% sure, but that description sounds very much like the 4-jaw chuck for Sherline?  Also, not sure if that is self-centering - I think they have both versions?  Someone with a bit more knowledge of the technical attributes may be able to confirm or eliminate this as an option?

 

cheers

 

Pat

[DerekMc]

Maybe one of the TAIG 4-Jaw chucks can be adapted?

 

TAIG Four Jaw Chucks

[Oliver Hoffinger]

Thank you to everyone who showed interest in solving the problem. It's unfortunate that so far no company seems to have shown interest in producing M16 4-dovetail-jaw chucks that are self-centering. It's not possible (for me) to find adapters M16->M33 either. It seems that either the safety risk has to be taken, or a specialized wood lathe has to be bought.
I wish you a nice day.

[bruce d]

Oliver, good luck with your search.  There is one further detail that hasn't been addressed and is important. 

The thread diameter is M16 but what is the pitch?  For example, the Unimat range of lathes use M12x1or M14x1 for their chucks instead of the common M12x1.5 or M14x1.5 pitch used by common bolts, some Sherline lathes have M12x1 but most are M12x1.25, and so on.  Forgive me if you already know this but the pitch of the thread must be established as mistakes can be expensive when ordering machine tools. 

 

Hope this helps, 

Bruce 

[Jaager]

I may totally misunderstand the situation, but my understanding is that a 3 jaw chuck is for round stock and as such a self centering action makes sense.

A 4 jaw chuck is for irregular stock.  It would be pure luck for 4 sided stock to be absolutely square.  It is logical for each of the jaws to be independent.

Round is almost always symmetrical.  It takes serious effort to make it anything else.  Four or more sided stock is almost always the opposite as far as having  symmetry.

[bruce d]

48 minutes ago, Jaager said:

my understanding is that a 3 jaw chuck is for round stock and as such a self centering action makes sense.

A 4 jaw chuck is for irregular stock. 

Your points about irregular shapes are of course right but a self-centring 4x jaw chuck is very useful for square (and rectangular) stock.   It is also good for any round stock and some say it has an advantage for holding round stock of softer materials because it spreads the load across four contact points instead of three.  

 

[Oliver Hoffinger]

15 hours ago, bruce d said:

 

The thread diameter is M16 but what is the pitch? 

Hello, thank you for your reply. The pitch is 1.5mm. I apologize for omitting this detail. I wish you a nice day.

[wefalck]

Self-centering 4-jaw-chucks are far and between, because they can and should only be used on square stock or parts. Sherline does offer one of the hobby market and that is the only one I am aware of.

 

Independent 4-jaw-chucks are very common and are either used for precision centring of round stock/parts with the help of dial indicator or, indeed, for irregular/rectangular/square stock/parts. There are many offers on the hobby market.

 

Sometimes and particularly in the USA independent 4-jaw-chucks are confused with faceplates with moveable jaws. Chucks, however, are meant to take up longer stock/parts, while faceplates are meant for mounting short stock/parts on their surface. On faceplates the jaws are sitting on the surface, while in chucks the jaws move in T-slotted or dove-tailed slots.

 

Incidentally, chucks with dove-tailed slots are rather rare today. Normally, either solid jaws run in a sort of douple T-slot or the jaws are in two parts, so that the top-jaws can be reversed or exchanged for other types of jaws.

 

4-jaw-chucks and faceplates have to be operated with caution, as the excentric load can cause vibrations and light machines to jump around, when not fixed to the workbench.

 

As far as I remember, PROXXON offers a metal and a plastic chuck for its light wood-lathe. The idea is that with plastic jaws there is less risk of marring the material.

 

I am curious what lathe you are using that has a 16x1.5 spindle-thread?