D1-4 pin installation

Hello all,
I was pretty heavily slammed shortly after the lathe's arrival, so I do
not recall how much I posted about it. Just in case, a brief re-cap,
and then a question.
My Enco 12x36 lathe lives! Rigging it was not too bad, though I was
wise to be suspicious about the connection of the skid (bolted to the
lathe) and the pallet: there was none other than the straps around the
crate that was built onto the skid! I ended up starting with a floor
jack to crib the skid and then slowly cut the pallet away to make room
for my engine hoist's legs. Once it was balanced in the slings, I
decided to go for and had the (already assembled) stand under it in a
few minutes. It was late, so the next day, I raised it slightly off the
ground and used 2x4 as a pry-bar to nudge the hoist across the garage to
its current location.
There was very little grit in the headstock, though there was a stray
machine screw. After some searching, it appears to have been a lost
screw of the type used to hold some of the front trim.
I built a 220 extension cord with a 15 amp double throw breaker in a $10
box to get it running.
So far, I have turned a little Al tubing, and noted that the 3-jaw chuck
(the only one I have used so far) was not running true. It appears to
be due to the pins on the back of the chuck. It was mounted to the
spindle when the lathe was shipped, and I suspect that either two of
them was installed too short, or one was left too long. It might have
been assembled that way due to some grit inside the hole receiving the
long pin. After some cleaning, I started to get it to sit down as far
as the other two pins _after_ my reassembly.
The chuck no longer runs untrue, but that is primarily because it no
longer mounts to the spindle :( I assume that I now have all three pins
at incorrect extension, probably screwed too far into the chuck body.
Unless the Chinese part of the instructions with my 4-jaw tells how to
mount the pins, I am w/o specifications. What is the correct way
(height at which, number of turns, etc.) to mount them?
Reply to
Bill Schwab
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The instructions go something like this.
When attaching the chuck to the spindle, the cams/tighteners should turn about 135 degrees. At least mine do. There are some marks on the spindle for this. If they don't turn far enough the corresponding pin is into the chuck backing plate too far. Turn more than half a turn the pin is not into the backing plate far enough. Adjust accordingly. Everything does need to be clean.
I would think there are instructions on the Enco site for this.
Bob AZ
Reply to
Bob AZ
This should help:
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Bob AZ
Reply to
Bob AZ
The CamLock pin should have a groove near the end of the thread. screw in until the groove is flush with the chucks back +/- one turn. The lock on the spindle nose has to be tight within 90° to 180° of rotation. Adjust pin on the chuck accordingly.
Reply to
Nick Mueller
3-jaw chucks don't center the work perfectly anyway, and they get worse as they wear. Their advantage is convenience. Use a 4-jaw for accuracy and also when you need to tighten the jaws hard. Jim Wilkins
Reply to
Jim Wilkins
Understood. The runout on 3-jaw chucks can be pretty large, but I am not trying to re-chuck anything yet, just learning how to get a good finish and getting a feel for the machine. However, this was not a dial indicator decision: one could see the chuck wobble from across the room. One of the pin holes was quite gritty, and my hunch is that they install the pin by feel: bottom out and then back off a certain number of turns, so the gritty hole ended up bottoming out early and the pin was "long" as a result - at least that would explain what happened. I might still have some work to do, but it is a lot happier than it was, simply by cleaning, re-inserting, and backing off one turn at a time until the cams worked nicely.
The 4-jaw chuck will get a workout as I learn my way around the machine. So far, I have been getting a feel for the gears. The feed levers were particularly stubborn. The right (numbered) lever is easy enough to move by turning the spindle. The left (lettered) feed lever was tougher to move. The only easy way I have found to move it is to manually turn the feed shaft. I have not tried threading yet, so I assume one might have to turn the screw when it is engaged.
For those who might jump in with saged advice, it is an Enco 12x36 geared head lathe.
Reply to
Bill Schwab
Pretty sure I got it, and at least one of them looks a little deep, consistent with a slightly short turn on the cam. I should be able to get it right now.
Got it.
Reply to
Bill Schwab
It did! When they refer to indicating "the cone," is that inside the chuck "below" the jaws? Correct me if I am wrong, but that seems to be overkill with a 3-jaw chuck?? It also would be unlikely to work well or at all on the fairly rough surface that I suspect one would use. My 4-jaw chuck is behind a tool cabinet that needs to be moved to a new home (making room for a bigger one purchased recently), and while I think I could lift it more directly, I am going to be smarter than that :) It would not surprise me to find a finished surface inside the 4-jaw.
That thread mentions using a torque wrench on the cams. Any takers, or is that going too far? If you do use one, what is your target torque?
Reply to
Bill Schwab
I'm not an expert on D1-anything, but I do have a Sheldon lathe with D1-6 and several chucks, backplates, etc. for it. The chuck (or back plate) has both a face and a taper that are BOTH supposed to seat to the spindle face. The taper of the chuck is a "female" taper that seats on a very short male taper on the spindle. You need the tapers to mate closely to get repeatable mounting of the chuck. You might check these with blue spotting dye. You probably don't need to actually lock the cams to get an impression on the tapers. I'd put the dye on the chuck, because the male taper of the spindle will be easier to inspect. Of course, you should get even transfer of the dye all around the spindle. You can also apply dye to the face of the chuck and see how well that seats against the spindle face. Again, it should fit relatively well, rather than at just a few points.
You said something about indicating the rough surface of the chuck ID. If thre is no ground taper on the back ID of the chuck or backplate, then I really don't think it can be called a D1 mount. It fits the machine's spindle, but it can't be mounted repeatably. I can't imagine using such a contraption. My Phase-II knockoff of the Buck Adjust-Tru chuck will grip any size round with less than .001" runout. (Yes, I bought it new, on sale, and it was a fine investment!) I took the backplate off a wrecked real Buck chuck that came with the lathe.
D1 mounts usually have an orientation mark, where one pin is marked to line up with one of the cams. usually there is an extra straight line by that one cam.
If the external taper on the spindle is not true, then you really have a problem. If it is true, and the dye indicates the backplate is fitting well to the face and taper, than mount the backplatew without the chuck and face it until it completely cleans up the front of the backplate. Then try remounting the chuck and see if it is better.
As for camlock torque, I just use the usual chuck wrench and make it snug. I tighen them all up a little at a time, maybe going around the spindle 3 times.
Reply to
Jon Elson
The document in the link above is from Jacobs, so I think it's likely the instructions are for mounting a Rubberflex chuck and the "cone" is the seating surface for the collets.
Reply to
Ned Simmons
The back ID is very clean, but if I follow you, there is no way to get to it with an indicator when the chuck is mounted on the spindle. The surfaces that are reachable are ok, but they are far from hardened and ground.
It seems to be running just fine now; again the problem was that the pins were (incorrectly) pre-mounted and the 3-jaw chuck was installed on the spindle in the crate.
Thanks, I will look for that. As with my mill a while ago, it is getting to be time for some directed light. The overhead lighting above and behind me doesn't cut it.
Reply to
Bill Schwab
I bought a cheap D1-4 mount and it had a turned taper instead of ground, for what I was using it for it was fine as great accuracy was not required. I will be wary of that supplier in future though and have bought more expensive, not by a great amount, D1-4 mounts which have ground location taper and face, I would buy those for anything accurate. The cheap one also had one of the camlock pin locking screw holes mis-drilled, re-drilled, and a thread insert to correct it.
Reply to
David Billington

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