rhncue wrote:

I've been seeing a lot of Jacob's collet chucks on e-bay lately and I've
noticed most are LOO or LO or other mounts for particular lathes. What I'm
wondering is did they make a chuck that can be mounted to a threaded backing
plate or if these other specialty chucks can be adapted to using a threaded
backing plate. I've got a 5C collet closer mounted now but I certainly like
the idea of being able to use the much larger collets. As I have never seen
one of these chucks up close and I don't want to buy one just to appease my
curiosity I thought maybe some one on this group would be knowledgeable on
them.
Dick


The big Jacobs collet chucks, the ones that take No. 91 collets, did come
in models to fit threaded lathe spindles but I've never seen one for a 1½-8
spindle. They made a smaller one for that spindle but they're really rare.
Another solution you might be interested in is what I use on my South Bend
9" lathe. I have an ER48-3MT adapter for which I made a drawbar. I mount it
in my lathe spindle and it holds ER48 collets, which go up to 1". They don't
allow stock through the collet but on the other hand they're dead concentric
(mine is, anyway, ETM brand). You can also use your ER-48 collets on other
machines with other adapters if you care to. At one time I used them on my
drill press (3MT spindle with drawbar) and my surface grinder (5MT toolhead)
and I also have an R8 adapter in case I ever decide to use them on the mill.

Grant