So, a tiny update on printed diffs.

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So, a tiny update on printed diffs. In mid July I added 0.15mm stainless steel washers on the in and outside of the case where the outgoing axle is. That is four washers in total on each diff. And the result is that I haven’t broken a diff since. I’m very happy about that even though I must admit I’m a bit surprised.

Originally shared by Daniel Norée

Friction sucks or actually heat+friction sucks. The differential with printed parts only has worked pretty good so far but as other parts in the drivetrain have gotten more durable the more stress is put on the differential.

My biggest problem has been the Axle shafts “digging” in to the diff casing due to the heat and friction.
I don’t really want to incorporate “non-printed” or “non-standard” parts, but I have made some 0.15mm thick lasercut washers to put on the inside and outside as seen on the pictures. More testing to be done.

As a sidetrack I have started to design a new diff or rather new gears in the diff to even out the pressure of the gears. More on that later, first priority is to make this work somewhat ok.

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Not too surprising. It’s kind of working like a thrust bearing as you would put in a helicopter blade head. (A thrust bearing would be better then two metal washers. It provides an alternate slip surface for side forces to bare (between the two washers). The teeth on the gears push each other away into the wall / bearing. To eliminate the non-standard parts, I wonder if you got some heavy duty aluminum foil and glued it to the case surface and the gear surface if that would be enough. Maybe even the fancy teflon coated tin foil (coating is only on one side)?

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What filament are you using to print your diffs now? The new Tritan filament from Taulman?

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@Adam_Thole the case for the front and rear are nylon. The case for the center needs to be harder so I have used PC but will switch to tritan. The axle shafts are PC. The gears are ABS. I tried a few other materials but so far I like ABS best for the gears.