Grbl_Esp32 VS ODrive

This post on github (https://github.com/bdring/Grbl_Esp32/issues/848) is exactly what I'm struggling with, but the recommendation is to update/change the firmware. I'm not sure how I can do that with the FoxAlien machine. gSender has a firmware flash option, but it does not have a profile for the FoxAlien 4040-xe, and "Generic CNC" didn't seem to change anything.

I understand you put thought and time into your approach and it was a hobby to learn more abotu the process (and thus you know about MPCNC but decided to make your own). I've also build similar systems and I've learned some timesaving tricks that have paid off in terms of hobbyist enjoyment.

I really like buying the majority of the parts from a place like OPenBuildsPartStore, rahter than assembling frames from channel manually. Time/cost/quality tradeoff is hard to beat here.

I strongly recommend switching to Grbl_Esp32 https://github.com/bdring/Grbl_Esp32 with external controllers (this board https://www.tindie.com/products/33366583/6-pack-universal-cn... with these plugins https://www.tindie.com/products/33366583/external-stepper-mo... and these controllers https://www.amazon.com/STEPPERONLINE-1-0-4-2A-20-50VDC-Micro...). That's what I ended up with because tuning current using the little pots is dumb, and you want a TON of current going to those huge motors. ESP32 + Grbl has a bunch of nice features that aren't in plain old Uno GRBL.

My system has high torque NEMA23 with no gears (same motor for all 3 axes), I can't see any situations where adding more torque to the X or Y axes using a smaller gearer stepper makes sense.

I have developed a new electronic board for laser machines that is using the wonderful ESP32 GRBL firmware and so compatible with all GCODE software including of course Lightburn

if you want to see how it's done in modern plotters/CNC, Bart Dring's [Grbl_ESP32](https://github.com/bdring/Grbl_Esp32) is fairly easy to follow with good docs. I have one of Bart's plotters, as I don't have space or money for an Axidraw with all my other old plotters around the place.

For actual optimization of input files, [vpype](https://github.com/abey79/vpype)'s the one most people use.

Going back to really old/simple plotters, there wasn't enough code space to do any optimization. For example, the (fairly terrible) Commodore 1520 roll paper plotter had 2KB of ROM for all the 6502-compatible code its micro-controller used. When I first looked into the [firmware](https://e4aws.silverdr.com/hacks/6500_1/), I was pretty shocked that it printed text by scanning a table of character data from the start every time. Then I realized that even storing pointers for each character would use up about ⅛ of total storage, and the mechanical plotter mechanism was always way behind anything the code could do. So small mattered more than efficient

Yup, and some modern steppers have this: https://github.com/bdring/Grbl_Esp32/wiki/StallGuard-Setup-a...

this fork is much more capable https://github.com/bdring/Grbl_Esp32

ODrive perhaps?

Well I dunno, maybe see how ODrive does it

Then maybe just hook everything to an Odrive and maybe add an Arduino or something to tell it what to do - although this also means you'll probably want an encoder at least on the pedalling motor to get accurate position/speed readings at low speed, since pedalling cadence is typically in the 60-90RPM range

If you want speed, use servomotors

This video may interest you, maybe also check this one and check out simpleFOC and/or ODrive

ODrive time?

Look at using some RC brushless motors driven from an ODrive board

You can probably replicate your own with appropriately sized RC brushless motors driven from ODrive boards. The boards can be linked together via CAN bus to communicate with your Arduino equipped with a CAN bus shield.

Thanks for the link! I know about simplefoc, the problem is the hardware. Simplefoc focuses on low wattage motors, e.g. a gimbal motor for a camera. For high wattage application, there's not much hardware available, and none that is affordable. There's odrive, which will set you back ~300$ just for the controller. Other than that, you'll have to go to traditional robotics companies.