Differential?

[MrForbes]

For the most part, automakers get around the limited traction problem of open differentials by inadvertently making the cars heavy and with suspension...it almost always takes care of the problem....

[dtengineering]

Originally Posted by squirrel

For the most part, automakers get around the limited traction problem of open differentials by inadvertently making the cars heavy and with suspension...it almost always takes care of the problem....

Until you get onto ice... it's not uncommon to see a new driver trying to get unstuck in the snow spinning one wheel while the other sits there unmoving. What the driver probably doesn't know is that while the speedo says "50km/hr", the wheel with traction is doing zero and the wheel on the ice is doing 100km/hr.

But hey... if you want to use a differential, go ahead and try one. Learning about what they are and how they work is a useful thing, even if they don't turn out to be the best solution for your robot. I can't help but wonder how many people learned a whole heck of a lot about planetary gearboxes while re-building their banebot trannies last year. :-)

Jason

[MrForbes]

Might also look into a viscous coupling, I don't know what's commercially available, but I think some of the riding mowers use them.

[King Duke]

couldn't use viscous coupling because of the hydraulic fluid used, however it was fun to look it up and see how it works.

[MrForbes]

oh....duh.....!

Sorry bout that

[Darunada]

Thanks Hachiban, that SDP-SI link looks promising.

The more I think about it, I'm thinking driving the weels seperately may be a good decision. That way, if we NEED to, we could implement a software differential. What are methods of doing that? Would we need to create a lookup table to map the speeds? Use encoders? We had terrible luck with the banebots encoders last year as our first attempt (Just couldn't get them calibrated!), and I think we're going to be hesitant to mess with them again....

[cobrawanabe1699]

A diff is overkill with robots this weight, and a Kart diff is not only heavy, but its also HUGE. I'm building a 2WD Radio Flyer with one of my friends, and we were shocked by the price (about $185) of one that wouldn't snap under any type of real tenion. This would not lose weight over dual CIMs. It would gain some.