Printrbot Simple Metal Z-Nut Mount for 8mm Trapezoid

thingiverse

I had to replace my Printrbot Simple Metal's imperial 1/4" Z-rod and z-nut due to failure of the Delrin z-nut, and it seems that Printrbot no longer sells this part. This adapter allows me to mount a 8mm trapezoid's brass z-nut onto the printrbot, which is a great option. This adapter places the z-nut right up against the bottom of the assembly, so I can use push forces against the znut-to-bracket. To make this work, you'll need: * Trapezoid 8mm rod + brass nut or delrin nut * 5mm to 8mm coupler * 2x button head M3 bolts that are 8mm and 20mm long One important thing to remember is to re-calibrate the Z travel with the M92 command after installing this adapter. For me, this meant setting "M92 Z269.44". Here's how I calibrated my Z travel: * Set M92 Z to a reasonable value, like 269.44 * Attach a digital caliper to the Z axis as shown in the picture, so that the depth testing pin can move freely while the caliper body remains in place. You should be able to get at least 30mm of travel. * Raise the Z axis 1mm at a time using the printer controls until you make contact with the depth-testing pin, then zero out the caliper. * Raise the Z axis 10mm at a time, and then do some math: New Z Steps = Expected / Observed * Current Z Steps (where z steps is your M92 Z setting).