Wanhao DI3 X Idler Upgrade

thingiverse

This is a Wanhao Duplicator i3 and clone x-axis idler upgrade. The stock idler pulley is only supported on one side, which causes it to skew with the tension, leading to mis-alignment and increased wear. This part uses a longer bolt to provide support from the other side of the carriage, keeping the idler pulley perpendicular to the belt. An M5x45 bolt is the only extra part needed for this design. The upgrade was inspired by The_Monstro's x-axis idler, but does not require drilling holes or disassembling the printer. This upgrade can be installed in place, but it may be a bit tricky: Disassembly 1) Raise the carriage at least halfway up the Z axis. 2) Release the belt from the print head. 3) Using a hex key, unscrew the idler bolt from the bottom of the carriage. This will be tedious since there is only room to turn about 1/4 turn each time, but fortunately, the bolt only needs to be unthreaded a few millimeters. 4) Once the bolt is released, you'll find that the pulley and bolt are jammed between the back wall of the carriage and motion rods. Unloosen the nut behind the pulley a few turns using a needle-nose plier through the hole the belt goes through and the hex key from the bottom, until you're able to remove the pulley and bolt from the bottom. 5) Remove the nut and bolt from the pulley, save nut for the new idler mount. Assembly 1) There is a threaded insert that the stock pulley mounted to. The printed idler spacer mounts over this protrusion. Thread the new bolt from the back side of carriage until it sticks out a few mm inside. Then use the end of the bolt to guide the spacer into place. It will fit snugly over the insert. 2) Bring the pulley with belt into position by the spacer, then thread in the bolt until it is through the pulley and flush with the end. 3) Use the nut that was removed from original bolt and press it into the hole of the new idler mount 4) Guide the idler mount from the bottom of the carriage up to the pulley with the inserted nut facing forward and the thicker leg facing toward the center of the printer. The left leg of the mount will align vertically with the hole that the belt goes through, and the part will fit snugly in the carriage. 5) Start screwing in the bolt from the back, feeling for if the bolt is aligned to the hole. When aligned, the idler mount won't push out from the carriage when the bolt is tightened. Try to keep the mount pressed down fully in the carriage, then tighten bolt as far as it will go until it is flush with the back of the carriage. 6) Re-mount and tension the belt