[Newbie] Using a stepper for power X-feed on a Sieg X2 mini-mill

[VicHobbyGuy]

One possibility is a noisy potentiometer.

Thanks for those ideas. I really appreciate the help I get online here.

A noisy pot is certianly a possibility - I just grabbed something out of my (some used, a few new) parts box. I did shoot some contact cleaner into it and give it a bit of 'exercise', but that's not a cure-all. Especially if the pot was pulled from old tube gear it may have had a hard life with too much voltage across it.

My scope is not at all digital...Kikusui6100M- but very nice and far more than I can appreciate. I have a few older analog signal generators and I hadn't thought of using one of them as the pulse generator for the stepper driver...I will try that.

 

[VicHobbyGuy]

UPDATE: I found a better (Clarostat USA) pot in my parts bin and that seems to have solved the 'losing its mind, stopping and growling" problem.
The square wave output from my older Heathkit audio generator also made it easier to put some numbers on the frequencies involved.
Thanks for the tips @Huub Buis ,@markba633csi , @homebrewed !
I think it's time to start drilling holes in boxes and mounting components.

 

[brino]

Also, many DSO's these days have an "envelope" mode where they can display multiple scans in an overlapping fashion. It's useful for checking things like jitter or abrupt changes in frequency. You might try that mode while monitoring the output of your 555 timer to see if anything unusual is going on.

Your 'scope might also have a special trigger for pulse widths greater or less than a certain value. That could help find an abrupt erroneous short or long pulse in the middle of a good stream.

Brian

EDIT: Ooops, I'm tool late to this party.

Well done @VicHobbyGuy !

 

[VicHobbyGuy]

I got it working and it is a big improvement over hand cranking and the cordless drill.
I got a lot of ideas - especially for the controls - from the article by David Haythornthwaite:
https://www.haythornthwaite.com/articles.html



I may still need to do some 'fine tuning' to get the low speed range exactly where I want it, but now that I understand the electronics better, that shouldn't be difficult.
Thanks to everybody here for the help given; I appreciate it.