My CNC router (2D) tool lift function is controlled by a solenoid, which lifts the tool when powered, and releases the tool when not.
I have recently started using these nice little 0.2 mm tungsten carbide bits, however while machining a piece of copper plate the other day, the dropping of the tool onto the work piece caused the very fine bit to snap off. I was able to re set the tool height and use the now slightly shorter and therefore wider (1mm) bit.
My question to you is: is it feasible to use PWM to soften the lowering of the tool?
I dont imagine that i would be able to control tool height this way (i am considering one day removing the solenoid and replacing it with a tool lift servo to allow this), however if i was able to reduce the solenoid power from 12V down to 0V over one or two seconds, rather than instantly, the tool might not freefall as dramatically and stand a chance of penetrating the work piece without busting.
iirc, the solenoid is controlled by the original transistors, which i am switching using an arduino. There are some pictures on my "Franken CNC" "something else" post.