3 jaw chuck

[jdm]

17 hours ago, Stevelp said:

I would like to try my hand at doing some different types of case finishes (circular brushing, radial lines of sunburst finishes etc.), and I,ve seen these finishes done on small lathes with the 3 jaw and the results looked quite good. 

A 3 jaws is fine but you must be prepared to also build your own arbors /expanding mandrels, etc because for certain jobs you won't be able to grab proper, or the jaws will be in the way, etc. Also, some work require the abrasive to be moving with the work steady,.

11 hours ago, vinn3 said:

 If you are new to running a lathe,  use a 3 jaw,  jacobs' and collets.  most nubies are afrade of a  4 jaw because it takes much more time to  get it "on center".  with some experience,  a 4 jaw can be put on center in15 seconds.

The thing is that  independent 4 jaws are a real rarity on a true watchmaker's lathe. Feel free, of course, to show us differently.

[nickelsilver]

I don't recall running across an independent 4 jaw chuck for a watchmaker's lathe yet, though I know they exist. I do use a 4 jaw on my larger (102mm center height) lathe quite often.

[Redwood]

I would love a watchmakers lathe but postage and import duty’s are more than the price of a little secondhand lathe from America, not many selling them in this country unfortunately 

[jdm]

16 hours ago, nickelsilver said:

I don't recall running across an independent 4 jaw chuck for a watchmaker's lathe yet, though I know they exist.

And here's the proof. Source lathes.co.uk

[rodabod]

Can someone here who actually uses a 4-jaw on a watchmakers lathe for case finishing comment on its use, as per the original poster’s query?

There’s no point in speculating about them. I strongly suspect not everyone here discussing them even owns a watchmaker’s 4-jaw  

Here’s my experience: 

I have a 3-jaw and have only used it for circular brushing and polishing of bezels and case backs. It works perfectly well for that application and is sufficiently concentric.