Don’t try printing diffs from PLA. The housing has melted after just one minute spinning at full speed. Similar on the other side. As a result the axle shaft has stuck to the side.
So what? ABS? Nylon? Maybee it will be better to use some pieces in metal for the diff?
Yea, PLA would not be suited material for OpenRC parts. But ABS should definitely stand up to the strains - many commercial diff housings are made from (albeit fiber-reinforced) ABS, even when they’re handling much, much larger power throughputs (even for big block nitro motors with ~4HP output).
Im using PLA in my differentals and i have never had any problems related to heat under normal use.
I feel instead that moment and especially pulses (from the road) is killing the differential. Especially with the new brushless motor. I belive the differential needs to be bigger to withstand the load. Maybe just scale the diff so the output shaft is 12 or 15mm instead of 10.
Wait a second, y’all are using printed shafts?
hmm, welding PLA by spinning. Have to remember that for another project.
@Chris_Vestal friction welding is actually a pretty popular concept in metal machining and, believe it or not, the production of many commercial R/C driveshafts involves friction welding the shaft 
This is why I am tentatively planning on using an AE diff, ball ends, cups, shafts, and tierods. Burning up a racing diff / clutch gives you a bit of confidence this will happen to pla/abs in one lap.