@wayneosdias Completely understand on not having the desire to take a custom project on.
I'm glad there are people like you who are willing to help out, and also give their designs out for the community.

I'll look more into the Duet solution and hope that something can come of that. At the moment i'm in the proof of concept phase. but it's looking very hopeful, Duet is a lot more flexible than I imagined before looking into it in earnest.

@wayneosdias that sounds like it would work for me very well.
My only hesitation on it, as said before, is the thickness of the populated board.

Part of that I can mitigate by soldering connector leads to the board, and having the connectors next to the motor instead of directly behind it, but if you use the same capacitors as the 1HCL, that kinda makes it difficult. those are pretty tall.

It also looks like you're only going 24v and 3.3v?
Is there any chance of there being space for a 5v regulator and some (pie in the sky) selector solder pads with resistor divider for the Encoder power/input?

Please don't take this as criticism. I appreciate greatly your willingness to share this board, and would gladly test it with my setup.

If I can get this proof of concept working/approved, and you're interested, my company is likely to be needing 250-300 of them to retrofit all of our current equipment.

@wayneosdias
If that is what I think, it looks very much like what I'm looking for.
Have you already made these boards? how tall are the components on them? (I have minimal back clearance, would like to not have to go to a shorter motor if possible)

@dc42 I believe it would. Current controller is on ancient stepper drivers at ~38vdc, I can't see newer drivers at slightly lower voltage being any worse, and likely better.

@dc42 Thinking about it. For this setup the perfect board would be one that fits on the back of a NEMA17 stepper, with mag encoder built on board, and 4 connectors broken out the side of the board. 4pin stepper power, 4pin quadrature encoder, 2pin power, 2pin can.

It's a pretty niche setup, but it's possible others might be interested in such a stripped down Closed Loop board. (if such would even be possible)

@dc42 That's a great Idea, that I didn't even consider.

But Sadly that won't work for me.

If the PCB were 1/2 the size in all dimensions then it'd be a maybe.

Background: I'm wanting to replace a custom control board with the Duet system, but am not certain I can get the Duet to be accurate enough for the application.

The System: We have what is essentially a custom CNC tubing cutter that is micron accurate. To get that accuracy we have high resolution encoders and an extremely reduced drive on a spindle depth drive, and a tubing feed drive. The tubing feed is spun axially with a third axis using a slip ring for connectivity to the motor/encoder for the feed.

From my reading it seems to be able to read the encoders at all, I'd need a 1HCL board, and set up the Linear quadrature encoder plus Duet3D Magnetic Shaft Encoder on each axis. For 2 of my 3 axis, this isn't really a problem, I have the space and can mount the electronics close enough to not have issue with signal. But for the tubing feed axis, the slip ring only has 8 contacts, and not enough space to change to a 12 contact slip ring. I MIGHT be able to change to a 10 position ring with some trickery.

IF the 1HCL can use 2 SPI encoders, AND I can set them up with only MOSI CLK and CS, then I could reach that 10 position max.
Stepper Coils x4, 5v, Gnd, MOSI, CLK, CS1, CS2.

The Questions:

• Can the 1HCL control in this Linear+Shaft encoder setup, an axis with extreme reduction drive? (ie 20k steps/mm reduction)
• Is there a way to use 2 SPI encoders instead of 1 Quadrature, and 1 SPI (magnetic) encoder?
• Can the 1HCL somehow do a Partial Closed Loop without the magnetic encoder for commutation?
• Is there a way to read the encoder ticks directly from the 1HCL without having closed loop setup? (So I can setup a partial closed loop by periodically checking the encoder counts and updating the movement commands)

Thanks

This would also help me,
With BiSS-C I would be able to select an appropriate encoder for my desired setup (17+ bit resolution required)

There's a post I found where someone was supposedly able to "read" a BiSS-C encoder with SPI in the "SimpleFOCproject" community forum. (can't post links yet, but search for SPI BiSS-C SimpleFoc and it'll likely come up. )

I would also benefit from being able to read the encoder directly.

My system does not work for Closed loop (no encoders have enough counts to be 2x+ my full step counts) but would like to implement meta commands with loops checking for acceptable range of encoder ticks since last referenced. Essentially exactly what M569.3 would provide.