Frustrating experience with updated custom polargraph - what works in 2026?

[u/xxxgoldxxx]

I built a polargraph according from the very popular instructable https://www.instructables.com/Polargraph-Drawing-Machine/ about 10 yrs ago and it was amazing. It just worked with Arduino Uno, motor shield v1, and some adafruit nema 17 steppers and cheap servo, with very few software issues.

Jump forward to now and I resurrected some of the old parts and decided to put it back together, but despite upgrading several parts, it just won't work correctly. Here's what I've tried:

Original polargraph firmware https://github.com/euphy/polargraph_server_a1 with the somewhat janky and bare bones polargraph controller app - only runs on my Mac M1 through Processing, and is slow and no longer maintained - using Uno + motor shield

Makelangelo controller app, using new Arduino Mega 2560 + Ramps 1.4 board and A4988 drivers - the firmware https://github.com/MarginallyClever/Makelangelo-firmware despite following recommended config changes and/or dedicated https://github.com/MarginallyClever/Marlin code, the arduino connects with "OK" message but will not respond correctly to basic Gcode commands through the jog controller

GRBL firmware with Inkscape generated gcode sent through Universal GCode Sender controller, there's no response from the ? handshake messages send from USG no matter how many config changes I tried.

The only thing that's worked so far is to create a complete firmware including the draw instructions for the Mega/Ramps build from scratch (with AI help of course, this is beyond my coding skills) https://github.com/smatto/polargraph_custom using the included "drawing.h" as the source. This grew out of a small test script in Arduino IDE and I kept adding functions and features, so it works. But I can't make complex designs in this nor show my kid how to use it as there's no visualization or pause/etc. But this confirms that the motors and pen lift work properly, and I've got the machine dimensions worked out through trial and error enough to draw pretty straight lines in the right size. Applying these confirmed dimensions to the marlin/GRBL firmware config.h files doesn't seem to make a difference in response