Saturday, January 23, 2016

3 Jaw Chuck

So far this year I have had almost no time for modelling as work has been rather crazy because the project I'm currently working on is drawing to a close. Hopefully once we get into February I should have a little more time. This also means that I still haven't had a chance to do anything with the lathe I bought just before Christmas. In preparation for having more time though I've just spent about 15 minutes stripping down the 3 jaw chuck on the lathe (which will be used to hold the things I'm working on), cleaning, oiling, and putting it back together. Given I haven't anything else to blog about I thought I'd show a couple of photos of this.

The first step is to remove the chuck from the lathe. To do this I had to remove the plastic cover over the belts to expose the pulleys and the end of the spindle. A 4mm bar is then inserted through the hole in the spindle and another into one of the holes on the edge of the face of the chuck (not the hole in the ring on the chuck). Holding the pulley steady with one bar I applied pressure downwards on the other to rotate the chuck ant-clockwise. Once it starts to turn it's easy to unscrew the rest of the way by hand.

Once the chuck is removed from the lathe then next step is to remove the 3 jaws. This is done by turning the ring anti-clockwise which opens the jaws. The more you turn the further out the jaws move until they can be removed. Each jaw is numbered and number 3 drops out first, followed by number 2, and finally number 1. With the jaws removed everything was carefully cleaned using whitespirit and left to dry before a few drops of 3-in-1 oil was used to lubricate the mechanism.

To reassemble the chuck you need to turn the ring until the edge of the screw is just to the right of the gap for the number 1 jaw. Slide the jaw in and then turn the ring slightly so it grips the jaw. Repeat for jaw number 2 and then 3 before then continuing to turn the ring clockwise until the jaws are as far in as you need. The chuck can then be screwed back onto the lather headstock spindle ready for use.


  1. I have used three jaw chucks but as I guessed a lathe was on the way I now predict a collet chuck and a set of collets. I have no idea of the cost but I would sit down before you open a quote. A four jaw chuck is an alternative but not really at the size you are working unless you want to turn square bar.

  2. Collets themselves are dirt cheap from China, which are perfectly good for our work. The chuck itself is a littl more expensive but well worth the investment, especially for milling. Check out Fohrmann for a collet chuck.

    Nice to see that you're starting to learn about your machine Mark. Every one of these little jobs helps us understand how our machines work. We should meet up.

  3. Rather smaller than my woodturning lathe (which I no longer have).