Thread: ER32 Collet Chuck for 2 1/4 x 8 TPI Lathe Spindle

G'Day all,

Thought I would post a couple of pics of a collet chuck I have just made for my lathe.

I could never get any better than about 0.003" runout in my 3 jaw chuck, so thought I would make a collet chuck to screw onto the spindle. I got the inspiration to make it after watching a guy from the UK make a similar chuck on Youtube.

The lathe is a HAFCO AL900a, which is the predecessor of the AL960B. It has been really good and accurate, with the exception of the 3 jaw chuck runout.

I chucked a piece of ground 1/2" rod into an ER32 collet in the new chuck, and the runout was 0.0002". Leaving the rod in the collet chuck, I removed it from the spindle and re-fitted it to see if the runout had changed. I was very pleased with the result, as the runout was still 0.0002".

It started out as a 75mm solid round piece of 4140. I already had the collets and a chuck with a 3MT spindle for my mill, so I just used the nut from that. I will get another nut, as they are readily available in Hong Kong for about $12 including postage.

Hope this will help others who may have thought about making something similar.


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Cheers,

Ned