Asadinator wrote:I’m not skilled enough to start from scratch :D
No shame there, because nobody starts out knowing this stuff ...
A cheap Chinese CNC machine kit (considerable assembly required) from Amazon (cheaper elsewhere, your choice):
https://www.amazon.com/Control-Engravin ... B07169D9JQ
You get about the same work area as the M2, a platform intended to hold down parts, a junk spindle you won't need, a crappy stepper controller with backlevel GRBL, and bag of "engraving bits", all for just over $200. Toss the crap you won't need in a drawer, assemble the rest, and verify that it more-or-less works.
Control the ultrasonic head with a solid-state relay attached to the spindle enable output, so you get easy G-Code control over the thing. If it has a PWM intensity input, the spindle speed control will do that for you, too.
Reflash the controller with current GRBL to get a solid G-Code parser & motion controller:
Now you have a low-end CNC machine with enough accuracy & speed for your purposes. The newer versions of GRBL include a "laser mode" that may be useful with an ultrasonic head.
If you're moving the head in geometric patterns or tracing shapes, then you can probably generate the G-Code algorithmically. Fetch the G-Code Meta Compiler:
Generate G-Code with a semi-high-level language and move on.
It'll take some learning, but doesn't require working around the limitations of Marlin, a 3D printer tool chain, and a hacked M2. The problems you solve will be directly related to doing what you want done, not battering software into doing something it's not designed to handle and figuring whether it's your design or battered code falling off the rails.
Bonus: this keeps the M2 operational so you can make the parts to bolt the ultrasonic head on the CNC spindle mount.
funnily at 75W as you mentioned
Well, 24 V times the 2-3 A you mentioned rounds off to 75 W, soooo ... [grin]