Steering for Differential Drive for 4wd

VEX V5 General Discussion General Forum
1

I built a 4wd version of the Rockcrawler from EricRobodux’ thread on the old forum:

http://www.vexlabs.com/forum/viewtopic.php?t=678

I did it without thinking about steering at all and when I was done found that steering in 4wd mode is very poor: lots of slipping, bumpy. Someone else on that thread mentioned the same thing. This is, of course, the same thing that I experience in my truck in when steering in 4wd so I wasn’t too surprised. I can likely think through the why’s for this one given enough time, but does anyone have a good solution for 4wd differential drive for the rock-crawler type robot (or 4wd in general…)

2

well powering both front and back, and then using two motors to turn it.

OR

Use omni wheels in the front, those turn very well, and use the back motors to turn it