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Can I cable a GRBL Arduino to the parallel connector of my CNC controller?

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vtsteam:
I added a 9 V power supply for the arduino. Upshot of testing this afternoon: motors and gantry all work, but two of the stepper drivers are bad.  :doh:

Time to order new ones. Presently the system has a 24V power supply w/ 8.3 amp output. The drivers are set at 2.7 amps each, 8 microsteps on 200 steps/rev nominal. So I have to find drivers that fit those specs.

vtsteam:
Drivers ordered. Should be here Tuesday.

vtsteam:
Well, ironic possible end to this story (maybe not): NO the motor drivers were not bad.

The impetus for this GRBL project was the loss of the old Thinkpad600e laptop I used to run the CNC mill.

Since I last wrote here, I was able to get the software off of the old Thinkpad's hard drive, and image that onto the hard drive of a Thinkpad T43 laptop. And then to get that laptop's latency down via a kernel patch, to be able to run the old LinuxCNC version I had always run with this CNC mill. The T43 has a parallel port.

I therefore removed the GRBL Arduino, replaced the old parallel port breakout board that I had removed, connected up the Thinkpad, and......surprise, surprise, everything just worked! No problem with two of the drivers -- they all worked. And happily cut aluminum as commanded.

Soooooo.....something was obviously wrong with the whole GRBL scheme. I don't know why it was so flakey, and worked with only one axis. I'm wondering if it was a timing thing? Step and direction pulse width? I know you could adjust those in at least one of the CNC programs I tried. Maybe it was set too short? I don't know. I've never successfully been able to get an arduino w/GRBL going consistently.

By comparison, the LinuxCNC seems completely stable and usable.

I don't have a pressing need for the GRBL conversion now, but I get curious about this kind of stuff. I still wonder if the adapted cable would have worked, if indeed the only problem was a pulse width setting, and not the conversion itself?

Hard to let that go, even though I don't need to find out any more....

ps. I now have 4 additional brand new stepper drivers that I don't absolutely need.  :bang:

ddmckee54:
Vsteam:

I know this is a zombie thread, but since you had those 4 stepper drivers just sitting around...

Have you built another CNC yet to put them to work?

vtsteam:
I have not, dd. I have to admit that I'm mainly a manual machine person and get caught up in CNC every once in awhile when I have something very specific for it -- like lettering, or in a recent case, a milled out tiny yoke for a Scotch youke mechanism.

I was just thinking about what I really like is lathe work, more than milling. I'll go to great lengths to do something on the lathe that would be easier on a mill -- and I do own a round column mill. But It's a hike to get to from the house in an unheated shed, and like I said, I don 't really enjoy millwork.

The lathe was my first machine tool, and I built it from scratch, so I have a long term fondness for it. Actually thinking even more about it, I like casting even better than lathe work, and pattern making nearly as much as casting.

Okay, back to CNC, to me it's like a crossword puzzle -- I can get caught up in it temporarily, all the CAD, file generation, setup, etc. But for me it's mostly empty calories the only really enjoyable part is the result. While with pattern making, casting, lathework, it's the activities that I enjoy, at least as much as the product.

The other problem for me with CNC is that I tend to forget, and then have to re-learn all the details of programming, setup and operation. I just don't use it often enough to keep that stuff current in mind.

But I'm sure I'll return to it as I seem to circle back to most things I've done before, sooner or later, when a special need arises.

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