I recently had the opportunity to help a friend, Brad Isdrab, with his pan-tilt-zoom stop motion camera rig. He was having trouble 3D printing some herringbone gears needed to couple the servo motors to the frame. He was working with ABS plastic and the gears were not holding or meshing well.
I had a roll of Taulman Bridge Nylon in my storage bin just waiting for the right opportunity to make something interesting. A gear project was perfect. Nylon has some special properties that make it great for gears. It's very strong and the layers bond well. Most dry plastic gears will slowly grind away the teeth. This creates plastic dust and eventually leads to failure. Nylon has the property of being somewhat self lubricating and this helps them mesh smoothly and last much longer.
The trick to getting a good print out of these was to slow down a bit and use slic3r settings that avoided any kind of blobbing on the surface of the gear teeth. For most of these that meant printing one at a time, setting all speeds to the same value to maintain a constant nozzle pressure, disabling retraction entirely, and forcing the slicer to keep travel moves within the outer perimeters of the model. Because the nozzle never stopped moving to un-retract and never crossed the outer perimeters there was never an opportunity to overheat or accidentally drop some extra plastic on those precisely shaped teeth. Because this filament is still very prone to warping I used a one layer brim to make sure it would stay stuck to the bed even while the edges were trying to curl up. You can see some of this brim still on these gears as I didn't have time to trim it all off before taking photos and delivering them.
My print settings were 60mm/sec for everything, .2mm layer, using the new cubic infil pattern available in the latest Prusia Slic3r. I printed these at 270C with no layer fan on a 55C glass plate using good old aqua-net hairspray for adhesion. My hot end has been significantly modified and I'd recommend starting out at 30-40mm/sec and slowly raising the speed until you see problems.
None of these are my design. I just managed the printing of the gears themselves.
Here is Brad's assembled PTZ rig. Most of the structure of this is printed in clear ABS which looks a lot like nylon in the photos. Just be aware that only the gears in this are nylon. Here is a video he made of it in action.
I have a history of working in stop motion production and this was a really exciting project to help with. I love supporting creative people and this made me really happy. I can't wait to see what Brad does with it!