half nuts and thread counter

[steamingbill]

Hey,

Reality check please.

When I engage my half nuts to cut threads the thread counting dial stops completely.

Then when I disengage the half nuts the thread counting dial starts turning again.

Happens every time.

I found this a bit confusing as I dont see how it knows where it is and where its been whilst it was not turning.

But maybe I just dont understand how it works.

So I am asking for a reality check before I start pulling things apart.

Does it sound like something is broken ?

Bill

[snapatap]

The dial is working perfectly. The dial is driven by the lead screw so when the half nuts are disengaged the dial will turn because the movement of the carriage is out of sync with the lead screw. When the nuts are engaged the carriage moves in sync with the lead screw and the dial doesn't turn. Sorry if my explanation isn't very good I'm not good at writing stuff like this. Try this for a practical demonstration. start the spindle and watch how fast the dial spins. now move the carriage towards the tailstock the dial should spin faster because the movement is more out of sync with the lead screw. now if you move the carriage back towards spindle the dial will turn slower because you are closer to being in sync with the lead screw. I hope this helps, maybe someone else can explain it better.

[steamingbill]

Snapatap,

Thanks - your explanation was fine - I understand it now.

I can see it in my head now.

Will go and do some thread cutting tomorrow.