Makergear M2 Improved Platform: Mechanical Adjustments

The PCB under the improved flat-top glass platform has three soldered-in-place M3 screws that fit the M2’s Y stage support:

M2 - Improved HBP - bottom view
M2 – Improved HBP – bottom view

I applied a tiny rat-tail file to the holes until they became a free sliding fit for the screws.

The wave springs are mostly decoration, as the silicone rubber disks now take the compression load from the screws, and the platform is quite rigidly mounted.

The new platform eliminates the M2’s original aluminum support spider, the aluminum heater & heat spreader, and the corner supports & clips, all of which add up to about 780 g. I didn’t bother changing the Y axis acceleration to match, as all those numbers seem rubbery.

Minus the support spider, the platform rides much lower on the Z axis stage than the M2’s platform. Unfortunately, the Z-min switch clamped to the top of the rear Z-axis guide rod can’t get any higher, even after rearranging the cable and fiddling with the LED:

M2 - Z min limit switch
M2 – Z min limit switch

As a first-pass hack, I moved the switch to the rear of the X gantry and applied Gorilla Tape to hold it in place:

M2 - Z-min switch at rear X gantry
M2 – Z-min switch at rear X gantry

That required a small block to raise the platform enough to activate the switch before hitting the nozzle. I epoxied a snippet of brass rectangle tube to the left edge of the platform, directly under the switch lever:

 M2 - Improved HBP - rear switch tab
M2 – Improved HBP – rear switch tab

The awkward position activates the switch with the platform as far to the rear as possible, so that you can’t inadvertently drag the dangling switch lever across the block in the wrong direction.

I think it’s stupid, too, but it let me bring up the printer and make sure all the electronics kept working. The next step was to relocate the switch to a more rational place