On Feb 21, 2:28*pm, "Bob La Londe" wrote:
I am currently making an adaptor plate to mount a 3" 3 jaw chuck on a 4"
rotary table. *Its pretty seems straight forward if it works.

1. *I am CNC milling the back of the plate to be close to an exact fit to
the surface of the table. *That job is running right now. *Because of
backlash in the Taig I machined exact size to the t-slot grooves. *After its
done I will measure and remove additional material as needed. *This should
put the rough form very close to center on the table.

Here is the rest of the plan.

2. *After the form fits I'll go back and center spot to drill holes to mount
the adaptor to the table.

3. *I'll drill mounting bolt holes for the adaptor, and mount it on the
table. *If there is any slop, I'll try to rough adjust it to the center of
the slop when I tighten the bolts into the t-nuts.

4. *Then I will mount the table on one of the manual mills. *Its slightly
too big for either of the CNC mini mills without a base adaptor mount.
(That is the next project) *Then I will rotate the table while cutting to
create a register for mounting the chuck. *This should give me exact size
and center. *(pretty close anyway). *I will also cut an outside surface
reference on the plate. *It should be concentric with the register, and
centered the same. *This will make later steps easier.

5. *Dismount plate from table.

6. *Coat back of chuck with grease and slide onto register.

7. *Drill chuck mounting bolt holes in the gaps in the grease.

8. *De-Grease and mount chuck.

9. *Mount plate back on table.

10. *Indicate reference surface on adapter and final tighten plate mounting
bolts.

(All bolt holes are to be counter sunk for the bolt heads. *I am sure there
must be a flaw in my plan, but it will have to do for now.)

HERE IS THE QUESTION.

How would I approach the problem if I wanted to mount a 4" chuck on the 4"
table? *With the 3" there is just enough room to tighten socket head bolts
to mount the plate to the table, but no clue how I would approach it except
maybe with 2 adaptor plates or with a spool shaped adaptor plate. *I can
already see projects where I would like to have a 4" chuck on this table or
a similar one. *There is no central taper in the table. *If there was I
would have just bought a chuck with a taper on it already for the current
job.

(I am also working on a stepper mount design for this rotary table, but that
can come later. Right now I just need it to index a 3D part that needs to be
cut on 4 sides to remove all voids.)

I did one for my 8" Palmgren and the 1 1/2"-8 chucks off the Southbend
years ago. Made a bar to fit the T-slot on the table, just the lower
part, turned up an exact duplicate of the lathe spindle nose, drilled
and countersunk it for a hex bolt, turned the back end to a close fit
on the hole in the table center, slotted the back on the shaper to a
close fit on the bar, then drilled and tapped the center of the bar
for the mounting bolt. Took most of a Saturday. And when I was done,
I could fit the spud on the bar either way and it was still a tight
fit. Locked down, there was no movement at all.

Stan