Knob for Acrylic (M4 Hardware)

thingiverse

I needed a sturdy and ergonomic knob for a project of mine and could not find one. I designed this to use a single M4 nut and M4 x 20mm round head bolt per unit (Fitted to 4mm thick acrylic sheet). I exported both a lower resolution and a higher resolution knob so anyone wanting to use this can pick which to use depending on their needs for quality. Both slice well in Cura. I highly recommend to print the Multi_Fitment_Test_Part first to verify your printer can meet the needed tolerances. This test part verifies the fitment of the M4 bolt, the M4 hex nut, and the head of the M4 bolt all in one small 5-8 minute print. To use the test print, fully thread one M4 nut onto an M4 bolt and insert it into the test piece. It should be a snug fit, however should not require any tools to press fit. If the fitment is too tight, (Hole Horizontal Expansion) in Cura can be used as a bandage solution to get the fitment usable although this should not be necessary on a well calibrated profile/printer. To assemble/install. *Drop a single M4 bolt into the knob allowing the threads to protrude. *Press a M4 nut into the Back Plate. *Stick the protruding portion of the thread through the hole want this mounted in. *Using a hex key, keep the bolt from spinning and hand tighten the assembled Back_Plate until snug. *Using the hex key, give 1/4 turn to fully tighten. For the hole, Drill a 4mm or 5/32 inch hole where you want the knob mounted. 4mm will be a little more loose than 5/32 inch.