Slide Tester for Fast Phone Docker

This is a test print to calibrate your offsets for the Fast Phone Grip.

Print -- do some light filing to remove burrs, and test. Note, for some reason, the test strip printed has different tolerances than the grip base... Test on the phone grip base after you've printed it, but before generating the racks. (note -- use a small file to clean the grip base a touch before testing) Enter the number above the test piece into the 'clearance' field in the customizer for the racks