pic: 6wd chassis - need feedback

What size wheels do you plan to use? At first look it seems like your wheels may hit your outer rails. If so, you will need to slide the dead axle mounts toward the center a bit. You can get an inventor wheel assy and add it to see how it fits. Also, I recommend dropping the center wheel 1/8-1/16. You can use chain tensioners like those on AndyMark’s site. If you add sprockets to your wheels then you can also check your chain clearances. Make sure your sprocket size is such that you do not hit cross members. You should be able to cantilever your center wheel off of your direct drive axle, so no bearing in outer plate.

The design is a refined copy of last years robot where we used Omni’s on the 4 corners and AndyMarks for the center drive wheels (all 6" obviously). Really worked well for us with 0 drop on the center wheel. I have this particular design completed with shifters and wheels so there appears to be plenty of clearance for everything (although I need to double check the sprockets for interference with standoffs in the wheel modules. We will consider different design options depending on the game.

we don’t have the option of bending the aluminum - at least not that I know of. The shop we were going to use for the welding may have something though.

thx again for the suggestions.

Quick Question, are you planning to bias your center wheel? My team is notorious for our crazy tough 6 wheel drive chassis (sorry i dont know a huge part on the structure of it) and we always bias our center two wheels down just a little. this allows you to be able to turn much better than with all 6 wheels planted on the ground. another thing we prototyped in '07 was a 6wd, center biased. we cut part of the front section, re welded part of it in while installing some hinges, and made it so the front third of the robot, just the part holding the wheels, would articulate downward using some pneumatics. this way, with the push of a button, we could switch from having only 4 wheels on the ground for maneuverability to having 6 down for brute pushing power.

just an idea but you can look into it.

message me if you have any questions, i might be able to get you some schematics.:smiley: