New 6wd frame, all wheels are driven (6’’ wheels), 1’‘x3’’ aluminum tube frame (1/8’’ wall), bane bot p80 dual CIM gearboxes (need help with gear ratio), I don’t know if the center wheels should be 2’’ wide IFI wheels instead, I’d like more traction for defense, but I don’t want to sacrifice turning (who doesn’t), would wider center wheels help? Anybody have any experience with the p80’s in drive-trains? Any better way to lose weight? I cheese-holed at will. Compliment and criticize away!!!
With omniwheels at all four of the corners, the robot will turn without significant effort.
You should recognize that as a potential problem in itself. Depending on other factors, it might be difficult to control, and it might be undesireably easy for other robots to spin it by pushing on a corner.
Would thicker center wheels help at all, or should I consider 8wd with the center 2 pairs as close together as possible (I don’t want too much wear on the wheels this year)
Since you have a single speed, I would recommend against wanting more traction for ‘defense’. If your wheels stop slipping and your motors are at full power, something is going to give – either a current breaker, bolts, gears, etc.
Small critique – the digital sidecar is miles away from your cRIO in the CAD. I don’t think there’s a COTS cable long enough to go from the cRIO to the digital sidecar in your drawing, so perhaps consider moving them closer. If you’re worried about EMF through the CIMs, consider making wiring channels above your P80 gearboxes. Also plan to put your wireless router in a more accessible spot (perhaps it can trade places with the digital sidecar?). Ethernet cables are cheap, lightweight and shielded so it doesn’t matter how long the wire from the router to the cRIO is.
you can make your own cables for the sidecar… did that in 2010 using 2 plugs (a male and a female), generic ribbon cable, and a vice.
That said, this is one of the many times where there may be a difference between CAN and SHOULD.
Good point with the cable, I was running out of room, and I wanted the spike and victor banks to be close to the power distribution and side car, haven’t made a cable before, I also wanted the solenoid breakout on the cRIO to be close to the pneumatics, which will go close by the cRIO.
You could also swap one end’s omnis for a pair of traction wheels of some form. That’ll give you–for turning purposes–a half-length, full width 4WD, instead of your current 2WD (again, for turning purposes).
You also may want to move the battery closer to the outside of the bot. You are going to want it there for easy access between matches. Just remember to redistribute the weight over you center wheels with the rest of you bot (manipulator).
Sounds like CimBotics Kit bot on steroids. My head mentor suggested a 6 wheel drive system, I just don’t like that it always is a sacrifice of turning capability, or loss of stability due to wheel drop that adds rocking. Anybody have any experience with the p80’s? What kind of gear reduction? Last year we used stock toughbox minis that were 12.75:1 with 4’’ plactions. I’m trying to direct drive 6’’ plactions with the bane bot p80’s, but they only come in 4:1, 12:1, 16:1 ratios, not too sure what we should go with.
I’ve seen that work well… especially if you make the two traction wheels close together.
It works especially well if you adjust your robot’s balance to favour the paired traction wheels. The omnis would only be used if the balance is upset. (Obviously you’d have to decide if that’s possible for a given game.)
And while we’re waiting for the next game to be revealed, why not sketch out a wide-based version of this design? There have been numerous FIRST games in which the narrowness of the robot wasn’t an issue, and wide 4WD bases made a lot of sense.