Stopped by a local used machinery dealer today, couldn't find what I
was really after, ( a compound for a Clausing 1300), but I did see a
used tailstock MT mounted turret that I bought. It has (6) 1" diam.
plain bores with set screws for holding a tool in each bore. Looks
like it might be handy for some bushings I need to fab. What is the
normal method for mounting drills with one of these? I'm thinking of
making some simple split collets machined to size for each drill from
drill rod. One JT adapter came with the unit. It is straight with a
flat on one end, and a JT taper on the other for a chuck. I could
mount multiple drill chucks, but given the stick out, I wonder about
the rigidity of the setup in this case. The largest drill would be
5/8" so maybe this is not really an issue. The Leblond tailstock this
is going in weighs 400 lbs., so it's stability is not really a
problem. Does anyone sell JT to 1" straight adapters ready made?
Hmm ... I've never used one of those -- though they keep coming
up on my eBay searches for Morse Taper gauges. I do have a bed turret
(replaces the tailstock) for my 12x24" Clausing, and have used quite a
few different tools designed for turrets.
As for that JT adaptor -- is the cylindrical part hardened and
ground, or mild steel? If the latter, can you set up a taper attachment
on your lathe to turn a proper Morse taper (to match your tailstock)
from it? You don't mention what the Morse Taper is in your tailstock,
so I don't know whether you can turn it or not. (Or are you looking for
arbors to adapt drill chucks to the turret? I guess so, re-reading some
of the above.
Yes -- cylindrical to Jacobs Taper arbors are available, though
they usually don't have the flat -- which is probably to keep the
setscrew from leaving burrs on the shanks which make it difficult to
remove the tools when it is time to set up for a different project.
Note that there are also female Morse taper to cylindrical
adaptors which you can use to hold Morse taper shanked drill bits, and
for the smaller ones, there are Morse taper collets with flats in the
inside bottom to accept a pair of opposing flats on the bit to keep it
from spinning in the collet. I think that this might be the better way
to set up your multiple drill bits to keep from having too much
There are various tools which will fit the 1" bores in your
turret (which happen to match the bores in my bed turret). That is a
pretty good size. You can use Geometric die heads for up to 3/4"
threads, and releasing tap holders for internal threading, and floating
reamer holders, as well as the drill bushings which you are considering
making. However, some of these things (e.g. the Geometric die heads and
the releasing tap heads) will work better if you have a lever feed
attachment for that tailstock. It is difficult to keep the feed rate
right with the feed handwheel on the normal tailstock.
There are also T-bar knurlers which bring knurls in on either
side of the workpiece for a balanced load.
Also, there are roller box tools, which are sort of a
combination of a tool holder and a traveling steady rest for turning
down to the desired diameter in a single pass (usually).
One other thing which you are missing with this which is present
with the bed turret is a separate feed stop for each station, so you can
tune the depth of drill, or the depth of tapping, or stop the Geometric
die head before the chasers hit a shoulder on the workpiece. Also, the
bed turret self indexes -- when you withdraw it the full way, it
automatically advances to the next station.
I've been looking at the ones offered on eBay for the No 3 Morse
Taper (which is what my tailstock has), and wondering whether I could
get any use from it which I can't get from the bed turret. (Of course,
it is a lot easier to install than the bed turret, which is quite heavy
when loaded with tooling. I've set up a dummy lathe bed off the end of
the actual bed, so I can simply slide the turret into position after
removing the tailstock (which is not nearly your 400 pounds. :-)