turning micro parts

Hi guys!! I would like to turn aluminium with 1mm diameter in my lathe, but I can't... they twist and broke off when I entering with tool bit. Why? What I did wrong? I do have a Sherline 4530.

Could you help me? Do you have some pics or videos?

Thanks

Cesar Bossolani

What size stock are you starting with? Don't start with small diameter stock as the grain structure is very weak. Smallest stock I ever start with is 6mm. This allows me to get a good clamp on the material, and the grain structure in the stock is much more uniform.

How long of a cut are you trying to make? I frequently turn parts that are smaller than 1mm diameter, but I my cuts are only 1mm at a time. So for my process, if I need to cut something .5mm diameter that was 4mm long. I would cut down to .5mm diameter with a 1mm long cut. Then move to the next section and cut down to .5mm with 1mm long cuts, then the next, and the next.

If you try to make long cuts of such small diameter, it will twist and break as you mentioned. Also, high speed, if you have the 10,000RPM pulley set, use it. Reducing your chip load will also help. Use the sharpest HSS tool you have as well.

Hope this helps.

Thanks Mike!

I'm using 6mm, and I haven't 10.000 pulley set... I will try your tips and will post here my results!

Thanks!!

Cesar Bossolani

It also depends on the grade of aluminium you're using. 7075, 7076, ... are very strong types.