DIYbanter - View Single Post

wrote:
Hello,

First of all, I have an Acra (now Enco?) 9x20 Chinese bench lathe. This
lathe was given to me by a friend a few weeks ago and it didn't get
much use at all from him.

For some reason the thread cutting system seems way off. When I cut one
pass (say 16tpi) and measure the light cut with my thread guage, I'm
getting closer to a 17tpi cut. When I try to do a 26 tpi pass I get
closer to a 28tpi cut. I've checked and rechecked all of the gear
combinations listed on the chart and the are correct.

Additionally, when I try to use the thread chasing dial, I can never
get the same cutting pass. For example, I'll use strictly the number 1
on the dial and my second cutting pass will be right in between the
first cutting pass. I'll try it for a third pass and I'll get a whole
different cutting pass.

This is really frusterating! Has anybody ever heard of this before? I
was actually impressed with the quality of this Chinese manufacturing,
but now I'm beginning to wonder...

If pictures would help at all I'd be glad to take a few and post them.

Thank you very much,
Carter

Are you counting the "first" thread as one instead of zero? That would
give you one too many threads.
Randy