parameterizable belt tensioner

thingiverse

This is a custom belt tensioner designed to help identify and resolve vibration issues on printers. It features a knurled knob for making precise adjustments. Update: April 3, 2018 - Modified version suitable for use with 20t toothed idler and M3 or M5 spindle is now available. For this size idler, the knurled knob around the M5 nut is too small to be useful, so a flathead screwdriver is used from the sides to turn the nut. I recommend using a silver nut that can be marked with a permanent marker on one face for tracking turns and allowing more control over belt tension. This version is shown in the photo with the blue part, where the belt passes under the gantry and utilizes my GT2 tooth side belt clip. The parts required are easily accessible, but this design is specifically tailored for an OpenBuilds/Ooznest 'smooth idler pulley' (22mm diameter, 16.2mm high) and to fit on 2020 v-slot extrusion configured for pulling an OB gantry plate on wheels. Additional 20t idler parts have been added with the update. Feel free to modify the SCAD file to suit your needs! The key variables you'll want to adjust are partsOnly and beltVoffset. If you need to reduce the idler dimensions significantly, be aware that the belt may rub against the mount, requiring some additional work to create suitable space. Also note the 'reg2020flip' boolean to control which side the hole for mounting to the extrusion is on - or simply remove this cube and create your own mount. I've made an effort to document the code sufficiently; if it's unclear, I apologize in advance. Some parts do require support during printing. The STL files supplied have been processed with MeshMixer to include these supports. Be cautious not to overtighten the belt, as this can cause it to stretch and deform, leading to vibration artifacts being transferred to your prints after it runs out of elasticity.