Servobelt drive for LowRider2 CNC

thingiverse

This setup replaces the Y-drive on the Lowrider2 CNC from http://www.v1engineering.com. My build uses 80/20 15 series on the outer rails, 48" long x 42" wide. The servobelt drive engages the drive belt with a static belt so that the only area of stretch is between the rollers and the drive motor. Other advantages include: a) It gets the belt out of the way from getting caught on things. b) The belt rollers keep the rig aligned and rigid in X axis (and take some load). c) The Y plate doesn't actually need the center hole cut for the motor, resulting in a stiffer plate. The main disadvantage is that it takes twice as much belt. The belt is bonded to the 80/20 with 10mm 3M VHB tape. Although the bond is not super strong, the total surface area makes up for this, and end clamps keep it from peeling away. I also use one of the top YZ rollers upside-down on the bottom side with a printed T-wheel to add Z rigidity. Extra parts needed include: (2) M5x10mm hex-head bolts to adjust tension (no room is available for an Allen key). (2) M5 bolts and nuts for toothed idler (same as smooth idler bolts). (2) GT2 x 10mm wide toothed idlers. (4) 80/20 t-slot nuts for belt clamps. Extra 10mm wide GT2 belts. 10mm wide 3M VHB tape. (2) 5/16"x3.75" bolts for the lower Y idler. (4) bearings. *Update: The base spacer plate, pulley spacers, and belt clamps used to make the X-axis also run as a servobelt have been included. The stock mount is modded by slotting the holes and adding tensioning bolts (see pic). The belt pulley sides are also turned down a few mm in a lathe.