After having one of my mechanical endstops break, I decided to beef up the limit switch a bit. Using soldered leads to hold a limit switch in place is just asking for failures.

Here are end stop reinforcers for the X, Y, and Z axes on MBI printers.

MBI Mechanical Endstop:
http://www.thingiverse.com/thing:4971

Should also work with most clones. Tested on an R2x using MBI's "mechanical endstop" and Flash Forge's "axis sensor."

The X reinforcer requires 1x M3x0.5 screw with length 16mm.
The Y reinforcer requires 2x M3x05 screws with length 16mm.
The Z reinforcer uses stock R2x hardware.

I use Carl's Alu X-ends and the Bottleworks relacement Y endstop bracket. But others have tested this with stock R2x parts.

Thanks to Scott B for suggesting an improvement for the MBI X-ends. I've updated the STLs so all three reinforcers will work with standard 16mm screws and stock X-ends without modification.

I printed mine on an R2x at 100% scale, in ABS with a 0.4mm nozzle, with 2 shells at 60mm/s and 30% infill at 120mm/s. But the part is so small your acceleration settings basically control how fast it prints. Slow is good. Over-extrusion is bad.

The X axis reinforcer "nubbin" may print poorly due to insufficient cooling time for each layer. I haven't had any fit issues from that. But you can turn on purge walls or add a sacrificial tower to the print to give extra time for layer cooling.

Machines with significant backlash may have trouble with the smaller features. Make sure your belts are tight, and don't be afraid to drill out the screw holes if you need to.