This is a slightly modified version of the 39 tooth large wades extruder gear included with the Nophead Mendel 90 kit. I've added a bevel to the first few layers so when it's printed, you don't need to sand/file each tooth to make it mesh correctly with the pinion. There will be a slight reduction in contact area and as a result service life I guess but it's a small price to pay vs. all that sanding. As far as I can see it's manifold, I've printed it at .3 and .1 and in both cases it came out well. Your mileage of course, may vary..... Cheers D :)