Record CL3 Lathe Problem

Peter -

There's two possibilities, and I can't tell foor sure which is the case from your post. Either the pulley is moving on the shaft without the screws loosening, or the screws are loosening allowing the puley to move. It sounds like the latter.

Get some Loctite thread sealant. You want the penetrating type for use after assembly. Clean all the oil off screws and out of hole. There's a Loctite primer made for this purpose, Lacquer thinner will also work with a little more effort. After screws and holes are both clean and dry, reassemble and tighten good. Then apply a couple drops of Loctite sealant where the screws go into the holes. A couple hour's wait should do, but I suggest overnight. Should be no problem thereafter.

If the former, dimple the shaft or grind a small flat for the screw to seat against.

Jim

Peter wrote:

(clip) Thanks in advance for any suggestions. Peter ^^^^^^^^^^^ Another way to keep set screws from loosening is to put two in each hole. You may have to substitute two short screws for one longer one in each hole. After you firmly tighten the first, run the second one up behind it and REALLY torque it in.

Peter, I had a similar problem with my old monotube's pulleys. I went to Home Depot and found some longer screws (but not long enough to protrude above the bottom of the pulley groove), then used Loctite and had no more problem.

Ken Moon

Peter, another alternative is using a longer grub screw and a locknut. The best is the Loctite fluid. I too have a CL3 but have never experienced this particular problem in the last 5 years of using it in my business.

Hope you solve it, the lathe is a great tool,

Regards, Peter Charles Fagg Freshwater, Isle of Wight, United Kingdom.

You are already up to your armpits in good advice but I will add you should get new grub screws and some of the recommendations indirectly require you to do so. The bottom cup or serrations can wear and a new screw will give more bite on the shaft. Combine that with Loctite or double screws per hole should fix the problem permanently. Billh

billh wrote: (clip) Combine that with Loctite or double screws per hole ^^^^^^^^^^^^ I'm not sure this is what you meant, but double screws AND Locktite surely ought to hold. A belt and suspenders ought to keep your pants up.

Peter, I too have a Record CL3 - had it for six or seven years, but never experienced this problem. I replaced the motor about two years ago and struggled for some time to get the pulley off the motor shaft. Loosened the grub screw and expected the pulley to slide easily. It was only when I took the grub screw right out of its hole that I discovered a second screw underneath. The pulley on the spindle is exactly the same, one grub screw on top of the other. Tighten the first one down on the spindle, then tighten the second one down on top of the first. It's the same principle as locking two nuts on a bolt to prevent them working loose. Loctite may help, but you shouldn't need it.

Nigel Coates

I was adding to the discussion that new screws should be used since the cup rim on the bottom of the screw can become dull/worn and not bite the shaft as well as the rim on new screws. The bottom of set screws usually have a depression in the center with a raised ring (cup rim) for contacting the shaft. I was told by machinists some time ago to change the screws if a pulley loosens. Others mentioned double screws and Loctite which I would consider good insurance as well. Billh