Source for open differential?

[sanddrag]

If you find the HPI Baja car on their site, there's a link to a PDF of the manual, which includes an exploded view. This differential is probably the most readily-available and lowest cost COTS thing I know of that isn't the size of something like one out of a riding lawn tractor. I've never examined this unit myself, but I would suspect it to be of high quality. It is in the final stage of a 1/5 scale off-road RC car, driven by a ~1-2HP engine, so I would suspect it could stand up to whatever you're doing if you design it right.

If you build your own, I imagine you wouldn't be hardening the gears. That's definitely something to consider, since most differentials (including the HPI I believe) have hardened gears, increasing their durability.

[bjohnston115]

I built a Baja 5b ss and it is a beast! with the modifications i have done to the engine, i am getting almost 4hp out of it and 12k rpm. The diff was simple to build and works very well. They make one with a plastic case and a alloy case, get the alloy case. When i first saw the thread this is the diff i was going to reccomend and then saw someone else already had done so.

[Joe Johnson]

I don't know your exact application, but I would like to caution you if you are planning on using it in your drivetrain.

First of all, bevel gears are very tricky to get right. I know that some have managed to make it work but this is not the kind of thing you want to do lightly (or without a lot of heavy duty engineering support).

Second of all, do you really want a single wheel off the ground to mean that your robot doesn't move?

Look at all those pick up truck commercials. They all talk about limited slip differentials because it is well understood in pick up truck culture that a standard differential is a real pain if you get one wheel with traction and another in the mud.

I wish you well, but I hope that you find another path...

Joe J.