Endstop or Limit Switch

This is an endstop or limit switch assembly with integral mounting bracket. I made it for the X axis of a 3018 CNC mill, but it should be easily adaptable for other applications, perhaps with a longer or shorter pin as needed.

For the mill, the bracket screws to the outside of the vertical plates (10 mm thick) that support the X screw and guide rods. The actuator pin passes through a 3.2 mm hole and protrudes inside the vertical plates where the side of the X carriage can come against it.

I used brass threaded inserts in the screw holes for the switch and cap. It should be possible to pull them into the shouldered holes from below with a screw; no heat necessary.

The holes in the cap are sized to accept M2 flat washers below the screw heads.

The two mounting holes in the bracket are sized for M3 screws. The hole spacing is 12 mm.

EDIT - 4/15/24: Actuator pin axis is 12 mm above the upper mounting screw hole, so three holes in a vertical line, 12 mm apart is the hole pattern required.

Bill of Materials:

3D Printed Items

• X Switch Bracket

• X Switch Cap

• X Switch Pin

Purchased or Parts Box Parts

Limit Switch, 1A
https://www.amazon.com/gp/product/B07YKH3TDR/

M2 X 8 mm Allen head cap screw (X 4)

M2 Flat washer (X 2)

M2 Threaded Inserts, Brass, M2 X 4 mm long X 3.5 mm diameter (X 4)
https://www.amazon.com/gp/product/B07VBRF7P2/

Printing Info:

PLA

0.3 mm nozzle

0.8 mm shells

12% infill

Supports recommended for bracket