"Eric R Snow" tesnow@whidbeyDOTcom wrote in message
...
This is mainly aimed at those who use 4 inch rotary tables (RT) on
larger machines such as a bridgeport mill. I have a 10 inch RT, a 12
inch crosslide RT and an index head that accepts 6 inch chucks. They
all get used to varying degrees. One advantage of a
horizontal/vertical RT over the index head would be the lower height
and shorter overhang. The 6 inch index head has a lot of overhang and
rigidity suffers because of this. But all these types of heads have
basically the same form factor so getting a different head won't
change things. On small parts getting past the OD of the RT means lots
of tool overhand. But it seems like the 4" table with a dedicated vise
and chuck would be ideal for small work. And a lot of small work goes
through my shop. All these small tables seem to come with 4 slots
which may make it possible to fashion jaws that screw in and out of
the slots making the table a 4 jaw chuck. I have a 4 inch 3 jaw chuck
that has a 5C shank to be used in a collet closer. Modifying it to
become an adjustable chuck was easy and it would be easy to modify
another. If I did this the 5C shank would be removed and the back part
of the chuck would be made to attach directly to the RT. A 5 inch
chuck could also be made to fit the 4 inch RT and the RT could still
be used in the horizontal position because there is sufficient
clearance for this. Which brings me to the last advantage I can see
when comparing the 4 inch RT to the 6 inch index head. This is the
horizonta/vertical nature of the RT mount that makes it easy to go
from one to the other without having to indicate the table surface to
make sure it is either parallel or vertical to the mill table. The
index head, having the ability to be set at any angle also means that
it has to be indicated whenever the angle is changed. So, have I
missed anything? Are these little tables useful? Or are they just too
small, even for those who use them on desktop machines?

I've used the Sherline 4" rotary table to good effect a few times on a
Clausing mill. There's a separate angle mount for it that might be useful.

Mike