NOTE: "These are not the timing pulleys you want". No really, you want version 4, which is here: http://www.thingiverse.com/thing:36568 This is an OpenSCAD parametric model for making most any timing pulley that you need. It's designed to generate a model printable without support material (observing the overhang rule of thumb). You can configure it to fit the belt that you're using. The pulley can be fixed to a threaded shaft with a nut. On one side the nut (the setting for an M8 hex nut is configured for you already) will sink into the pulley. If you tighten a nut on the other side as well it will be very well fixed. Another option is to use set screws. You just specify the diameter of the screw and it will create a hub with a (capped) teardrop hole. The set screw option has been fixed in this version so that odd numbers of set screws (such as the very useful 3 set screw version) can be supported without the holes going out the back of the hub. An option has also been added to angle the set screws. The STL file included works well with the Synchroflex(R) timing belt,1500Lx10Wmm from RS (order code 474-5892), spliced in half (to 5 mm width). This way you'll have a very good belt driven system for about 4 euros per meter. The belt comes as a closed loop, but you may need to glue it to get it to the right length. Depends on teardrop.scad being placed in the MCAD folder. Won't always render with F5, use F6. // Superceded by Version 4: // http://www.thingiverse.com/thing:36568 // ////////////////////////////// // USER PARAMETERS // ////////////////////////////// // Pulley properties shaftDiameter = 26.289; // the shaft at the center, will be subtracted from the pulley. Better be too small than too wide. hubDiameter = 35; // if the hub or timing pulley is big enough to fit a nut, this will be embedded. hubHeight = 25; // the hub is the thick cylinder connected to the pulley to allow a set screw to go through or as a collar for a nut. flanges = 2; // the rims that keep the belt from going anywhere hubSetScrewDiameter = 7.112; // use either a set screw or nut on a shaft. Set to 0 to not use a set screw. hubSetScrewAngle = 90; //change from 90 to angle the setscrews numSetScrews = 3; numTeeth = 75; // this value together with the pitch determines the pulley diameter toothType = 3; // 1 = slightly rounded, 2 = oval sharp, 3 = square. For square, set the toothWith a little low. // Belt properties: pitch = 5; // distance between the teeth beltWidth = 4; // the width/height of the belt. The (vertical) size of the pulley is adapted to this. beltThickness = 0.65; // thickness of the part excluding the notch depth! notchDepth = 1.8; // make it slightly bigger than actual, there's an outward curvature in the inner solid part of the pulley toothWidth = 1.4; // Teeth of the PULLEY, that is. include <MCAD/teardrop.scad>