Smashed Z limit switch

As some of you know the moving the z axis past its actual hard limit destroys the limit switch.
Recently when looking for an idea to prevent this I noticed a small threaded hole on the top plate that hold the bearing and motor. Shown here below.

Now I used a bolt I had handy. Later I am going to replace it. This bolt hole is just over the bracket that moves the Z axis and will act as a stop to prevent the Z axis switch from getting crunched. I am not sure if this was a design intent but I thought I would share it. :slight_smile:

The bold I am currently using is a 2.85mm Diameter. Fine pitch threading. I am not sure on the thread size. Could one of you guys that are good at measuring the hole please post the proper fastener size.

That’s kind of a rite of passage for XCarvers.

By the time you’re on your 3rd or 4th switch, you actually start to check whether UGS is set on “MM” or “Inches” before hitting page-up several times…


Its a good thing those switches are cheap.

I thought the “hard limit” was after you destroyed the switch and it just would move anymore! HaHa

Yeah I killed the switch the first day of use 9 days ago, had a M3 bolt it fit fine but was to short. Home Depot has got M3 from 6mm to 40mm long. i got the M3-32 x 40 mm. Internal Hex Socket Cap-Head Cap Screws SKU #554330 ( but a shorter could work) and M3-0.5 Zinc-Plated Steel Lock Nuts SKU #230640. I put the bolt in from the bottom with nut on top.

I know but some of us need those physical limiting parts for our bumbling fingers.