pic: Toltechs drive-train teaser

[Andrew Blair]

Originally Posted by Rick TYler

Maybe eight inches is too high? It's important to remember that Poof balls squish. Here's a thought. A lot of teams are going to do sweepers that have counter-rotating rollers or belts designed to lift balls from the ground. Many of these will be slanted back, or have curved ramps that skim along just above the ground. What if, instead, the lifter was a belt that went up vertically, with a pressure plate about six inches away. The center point of the bottom roller of the conveyor is below the center point of a ball (how about 2-1/2 inches?), and the bottom of the pressure plate is about 5-3/4 inches from the floor. You drive the bottom of the plate over the ball, which, since you are impacting it well above its CG, starts to roll. The robot is moving faster than the ball, so it drives over it. The ball then rolls into the bottom of the conveyor which acts as a wheel, lifting the rear edge of the ball. The ball tries to roll forward, but, since the force from the belt is actually a vector pushing forward AND up, it rises a little. Once it lifts up, it becomes trapped between the belt and the pressure plate, which act just like a single-wheel shooter and a pressure plate or bar, and the ball walks up the pressure plate into a curved sheet, which walks it over into a hopper.

This must have come to me in a dream. I'm sure it's not the design we are using on Top Gun. Incidentally, this is a testimony to prototyping. We would have a sloped ramp with a curved Lexan floor sweeper (which would act just like a bulldozer blade and knocked balls out if we hit them going fast) and two rollers if we hadn't built three prototypes of this. Now we know exactly what geometry will work, and how fast the belt needs to go. Not that this is our design or anything...

This is actually the same exact idea that I had towards the beginning of the season. We are not using it either though...

[Rick TYler]

Originally Posted by Andrew Blair

This is actually the same exact idea that I had towards the beginning of the season. We are not using it either though...

Sorry for making humorous jokes and not being clear. This is how we will be lifting balls from the floor. The biggest advantage is that it only takes up 10 inches of length on the robot, leaving the rest of the real estate for the hopper/loader/shooter mechanism.

[Andrew Schuetze]

As promised, mentor D. Sean Kelly did a quick edit and uploaded a .wmv to our site, you can view the first cut of our robot driving in the shop. Not seen in this video is the code addition which allows us to complete zero degree spins in C.W. or C.C.W. via a second controller.

http://www.toltechs.com/Rocket/Uploa..._Holonomic.wmv