What drivetrain did you do?

[lukevanoort]

Like 1618, we are using a kitbot-derived 6WD with AM Shifters (Gen 2 Servos, in our case) geared to 13.3 and 5.3 ft/s. Unlike most kitbot-based 6WDs, ours has an adjustable centre wheel. We tried it coplanar, lowered 1/16", and lowered 1/8"; we found that we much preferred 1/8" to the other ones. Coplanar could not turn at all in high gear (but was awesome to drive in low gear - I can see why 25 likes it), 1/16" was faster turning in low gear and could drive in arcs in high gear (ie. you had to move forward to turn), and 1/8" can turn in place in high gear, albeit a bit slowly. We are only running 1 chiaphua per side though; if we had two per side, I'd probably go with 1/16" or 3/32" lowered.

[SL8]

we are using tanksteer with the 2 back powered by two motors each. We did not even bother with DeWalts this year. We did not believe that we would be able to get much speed in this game do to traffic.

[Sam N.]

6 wheels. Center wheel is dropped down 1/4inch. Turns on a dime and can make nice U-turns.

"6-wheel rocker"

[Andrew Schuetze]

AM supershifter /w servo 2 CIMS per side.
Belt driven four wheel drive /w 6 inch x 1 inch IFI traction tires wedgetop tread.
Belt reduction 3:4 after the transmission

[Richard Wallace]

8WD live axle with AM SuperShifters and two CIMs. We're using 2008 AM FIRST kit-of-parts wheels and a 2-1/2" x 1-1/4" x 1/8" wall tubular aluminum welded chassis, with tensioners based on the prototype that Jabba-the-Hutt made for us in the off-season.

[JHSmentor]

6wd with center wheels direct driven by kit box Toughbox - 2 CIM's per side, front and rear corners are Omni's - no center wheel drop. 4 custom designed spring/sprocket tensioners. We've clocked it at 10f/s but the weight causes it to take a little while to hit that speed. I would have liked a lighter robot by 10-20 lbs but that wasn't going to happen.

[AJ R]

We went with an omni drive. 4 wheels on the 45 degree angles just like our vex robot from the Milwaukee vex league. It works really good, really fast and good maneuverability. The programmers did a great job getting it to drive strait.

[s_forbes]

We were seriously considering an Ackermann set up, but then our programers figured out how to make a 6wd robot drive like one, so we just built a 6wd bot.

We had fun designing it, too. We aimed for super simplicity: the frame is made of four lengths of c-channel, and the wheels sit on protruding bolts. Very light and easy to fix.

RWD (2 IFI 6x2 traction wheels) powered by 4 CIM's through toughboxes; Front steering (non-Ackermann, non-powered, kit wheels).

[Daniel_LaFleur]

4WD, skid steer, run by 4 Cims through Dewalt transmissions.

[PhilBot]

Soap-Box style steering X 2.

Two pivoting axles, linked with a cross-bar to provide high-speed staight-away and turning. Each axle has a pair of CIM motors, driving inline 3:1 Banebots Planetary gearboxes and custom made 4" diameter traction wheels.

Original tests showed that we could drive and steer JUST using differential speeds on the opposing wheels, but we ended up adding a dedicated steering motor with position feedback for Hybrid mode.


See video of the bot in action:
http://www.youtube.com/watch?v=JKdTJSR-KuU

[T3_1565]

we invented our own drive system! (you may of seen videos of it on other threads) It called "the Linkage" and it is 4 omnis set up like 4wd, that switch 90 degrees so they are also 4wd in a sideways orientation, giving us 4 motors of power in all 4 directions without the mechanical no how of a swerve drive!

[Greg Peshek]

We did a true Ackermann type steering, with a ATV differential in the back, powered by 4 CIMS running through a modified AM 2 Speed Transmission.

[Wayne TenBrink]

6-WD. Omni's on the front, 2007 kit wheels in the middle and back. Two CIM's per side. Zero drop on center wheels. One speed at 10 fps. Stable & strong. Easy to turn, but doesn't spin out on fast corners.

[JOhnch181]

we are driving a 4wd using super shifter with performance wheels in the front and a kit wheel back right and an omni on the left. turns slowly in low but takes the corner perfectly in high gear.