Boxford 3C collets

I see advertisements for 3C collets to suit Boxford Lathes. Are these 3C collets different to others?

Theres a thread here,**LINK**

What do you mean by different? You usually need a spindle nose adapter like on my Southbend..

Edited By mark smith 20 on 05/09/2017 09:50:35

I have copied this post from another on 3C Holders but it is also relevant to this post.

"Many thanks for the responses. I assumed that an adaptor would be needed but I have seen someone on ebay selling 3C collets as style 327 to suit Boxford lathe and so wondered what was so special about them, or am I reading too much into that description?

I should say that I am not intending to use 3C collets on my Boxford (although it might be a good idea) but am researching info on an Edward Blake Tap Grinder. Having taken it apart I have measured the chuck, holder and drawbar and find that they are 3C."

Brian

I have a Boxford AUD lathe, 327 marked collets, and a collet closer for them. The couple of odd 3C collets I had from overseas awhile back had a different thread size and would not fit the closer.

Thanks Mike, the thread size on the grinder is approx 0.643 x 26 tpi . I have a Boxford AUD but no collets!

Brian

If you do use 3C collets with the 3MT adapter on a Boxford, it's well worth while getting the threaded nose-piece that screws onto the lathe mandrel. Not only does it protect the chuck mounting thread and register, it acts as a very useful extractor for the adapter, which gets very tight in the MT.

Clive Brown

Sorry, no understand. How does the spindle nose thread protector extract the 3MT adaptor?

Mine is knocked out from the other end.

I have metric round and imperial round and imperial square collets. Some are 3C, some are 327 (Crawford), and some are no name Chinese/Taiwanese sold via Shars in the States. ALL have the same 26TPI thread and the drawbar threads comfortably in ALL of them.

I think he refering to removing the adaoter that often can get stuck tight. The draw bar is threaded internally  on the end so your not supposed to use it for banging out the adapter.

On my southbend the nose protector when placed behind can be unscrewed to force out the adapter. as in photo of my southbend.

Edited By mark smith 20 on 05/09/2017 15:08:49

As per above. Knocking out will work, but, if done carelessly with a bar of undersized diameter it risks damaging the small peg at the rear of the adapter which is provided to stop collet rotation when tightening.

I'm just suggesting that jacking off with the screw thread is safer.

Thanks all for taking the time to answer. The thread is rather fine so I would not like to be hammering on the drawbar to remove anything. The jacking off idea seems very sensible.

Brian

I don't use the drawbar for anything else other than tightening or loosening a collet in the adaptor. The adaptor is knocked out using a close fitting brass bar.

I will check that out this salvo. Perhaps that's why the spindle nose protector has tommy bar holes. Never thought of that. Will get back here tomorrow.

Well, blow me down with a feather !!!

Only owned the Boxford for 15 years. The threaded spindle nose protector can also be used to extract the MT3 - 3C adaptor....

Who woulda thunk it! Ta velly much.

Has 4 tommy bar holes, so tommy bar or better still, a good fitting C spanner would undo it. In the meantime, keep knocking it out with my brass bar....