This is a modified version of http://www.thingiverse.com/thing:19227 the large 39 tooth herringbone gear for Wade's extruder. This version has a bigger Hex depth and a smaller 13mm diameter for the Hobbed bolt. The hole is now 8.0mm and 5.8mm thick for the correct spacing on the Mendel90. In the picture the original gear is left, the new one for the Mendel90 is on the right, just forget that one in the middle. I've used PLA on 210C with the fan on.