Spider coupling with Sugru insert mold

thingiverse

This spider coupling is a modification of MiseryBot's original design (http://www.thingiverse.com/thing:7678). I adjusted it to fit my 8mm diameter trapezoidal spindles, as the initial model was made for M8 threaded rods with a slightly smaller diameter. Additionally, I corrected the nut trap sizes to match ISO 4032 nuts, which were too small in the original design. To create a mold, I used the insert-positive and printed it with at least 50% infill for durability. To use Sugru, grease all parts of the mold gently, apply some Sugru (a 5g pack is enough for two inserts), tighten the top and bottom part of the mold with 10-20mm M3 screws and nuts, and wait for about 24 hours for it to cure. After that, cut off the top and bottom mold parts with a sharp knife, wait another 24 hours, and then push out the cured Sugru from the mold. This spider coupling is the best-performing one I've used so far, but remember to support the spindles with extra bearings for radial guidance and a fixing collar on top of one bearing for axial support.