Compact Belt Holder for OpenBuilds Gantry (using 4 wheels)

thingiverse

This is a vertically oriented belt holder for the OpenBuilds 2020 gantry (not mini), using four wheels. A version for three wheels readily exists but you may want to use four wheels for increased stability. **Printing:** Use thicker wall setting, e.g. 2 mm for strength, otherwise nothing special needed. Attaching the belt holder to the gantry: **1)** Disassemble the wheels **2)** The belt holder is placed between the static wheels (as opposed to the eccentric nuts) **3)** Push two **flat** M5 nuts into the slots, use a tool for assistance **3.1)** Regular M5 nuts or nyloc are too thick, use approximately 3mm thick M5 nuts instead! **4)** Screw the belt holder using two M5x8 (8 mm thread length, 9 mm is absolute maximum) **4.1)** I just dremeled longer screws to size **5)** Assemble weels and the rest back This belt holder is about as compact as it can be, as such the installation is a bit more fiddly: **1)** Take off the belt tensioner and gantry **1.1)** The gantry should be able to slide on from the side. On my CR10-S Pro I had to trim the screws and use flat nuts instead of the stock nyloc ones! See the picture for comparison. **2)** Loop the belt through the motor and pull both ends to the other side, so that they are inside the grooves of the 2020 profile **2.1)** The stock belt is likely too short, so buy a new one! **3)** Insert the first pair of wheels on the 2020 profile, and pass the belts between the wheels and the profile. For now stick the ends of the belt down the middle of the belt holder and keep pulling any slack as you push the second pair of wheels onto the profile **4)** Insert the belt tensioner as loose as possible; don't scew or tension anything yet **5)** Remove as much slack as possible, then pull the belt 90 degrees angle (away from the hotend) and fold the ends against each other, creating a 'heart' shape **6)** Trim the belt ends so they fit under the 2020 profile and push **simultaneously** into place as seen in the pictures **7)** Now tension the belt with the idler **8)** Take a moment to admire your accomplishment!