[bennieg]

I recently purchased a HF 7 x 10 mini lathe. I got it home and followed all of the instructions on cleaning and set up. It came with the inside jaws in the chuck and I changed them out to the outside and made sure they were in the correct slots. I installed a 1/2" aluminum rod about 1 1/2" into the chuck and turned it on. I immediately noticed the rod is not turning parallel to the ways and it is about .0625" out. I tried re-seating the jaws and that does not correct the problems. I also tried it with a piece of 3/4" bar and the same problem

Does anyone have any suggestions as to how to correct this problem. I would appreciate any guidance you may offer.

[doorknob]

I know that I'm not answering your question directly, but the inside chuck jaws should also be capable of holding the outside of a rod. Did you check the runout when using the inside jaws? They should have a larger contact area than the outside jaws.

See this photo from Mini Lathe Chucks

Attachment 220860

[bennieg]

Thanks Doorknob. I will switch jaws and try that. I have always wanted one of these and am getting a Grizzly mill also. So I will probably be asking a lot of question here. Again thanks.

Bennieg

[elfrench]

Try moving the jaws to different slots to see if they fit better, just keep them in the order.
Do you see the same runout if you turn the rod down until it's running true, then reverse it?

p.s. You need to say how far from the chuck you measured the runout. It is a lot bigger problem if you're measuring at the chuck or a couple of inches away.

[bennieg]

Thanks Elrench.

I measured about 3"s away from the face of the chuck. I will try rotating the jaws.

Bennieg

[bennieg]

Would a 4 jaw chuck reduce the alignment problem?

[elfrench]

I don't think aluminum rod makes a good test bar. It's soft and the jaws may bite into it, which will affect the runout. One source of hardened steel rod is automobile shocks. Most repair places will give you old ones free.

What is the runout measured at the chuck? You should use a test indicator for this, they're (usually) more accurate than dial indicators.

Everyone should have a four jaw chuck if they need to do high precision work. They do take a while to learn how to adjust, but once learned it is quite fast.