pic: Frog Force 503 Omnitank Drivetrain (rAC)

[asid61]

Originally Posted by Electronica1

The reason I bring this up is that every iteration of the rear drop (my name for this style) hybrid drive I have seen has the wheels all geared the same and has a transmission to switch speeds. I believe that in a pushing match/change of direction the piston would give a little and all the wheels would be on the ground.



Please tell me you aren't using 25 chain for this. From what you described, you might run into the issues the mk1 version of my teams octocanum had. It worked fine in the shop, but in a competition setting, the stresses on the 25 chain from shifting caused our chain to stretch every match, we later found that during defense it could even shred the chain. We tried switching to 35 chain that summer and haven't run into the issue since. If your chain is getting loose now, it won't stand a chance at competition.

(Just an fyi, we had this issue with a drive that only had 4 cims of power, I have a feeling that the 6 cims might make this issue more prevalent)

The chain should not stretch in any kind of tilting transmission like this one if you design for it. If you make the sprocket concentric with the pivot point it should be fine.

Also, any kind of tilting transmission I've seen usually gears traction wheels for a lower speed than the omnis or mecanums. It seems like a huge waste to have a shifting gearbox when you have the gear the two wheels together anyway; why add another stage of gears when you don't have to?