Well, our robot is done… except we’re still fine-tuning the mechanisms.
We will be changing out the two pneumatic cylinders for our Spinny Grabbers for one Nitra pneumatic cylinder from Automation Direct tomorrow night (assuming weather doesn’t cancel us). We already bent the rod on one of the previous cylinders by dropping it onto a cone, so we tried to build a “cage” around it to protect it. That didn’t work. The new cylinder is in a protective casing and should work. But you know how that goes…
The new cylinder will eliminate the need for the spring boosters we had for the intake, also, and simplify the structure overall.
We haven’t really said much about our mechanisms. We started with the standard drop-wheel chassis and made it 23 inches wide to assist in fitting 3 robots on the charge station. It’s 32 inches long, which might make maneuvering it a bit dicey, but that’s why we did the drop-wheel chassis, to shorten the drive base.
We put a “Strongback” towards the back of the chassis. It’s made from the REV Max tube with the grid pattern. We connected all the pieces using gussets and corner brackets, which make it really stable, so no side-to-side movement. At the top of the strongback we have the Extendomatic arm. We took a REV elevator kit we bought but didn’t use a few years ago and made the extension from that. We tried hinges to attach it at first, but that didn’t work well, so we switched it for a 1/2" hex shaft.
The setup gives us more range of motion in the arm, allowing us to extend it high enough to place cones on the upper node.
The Extendomatic moves in and out using a Redline motor attached to a lead screw. We need to modify the mounting of the motor a bit, since the screw, which is 3 feet long, wants to run into the cylinders on the Spinny Grabber. But since we’re changing out those cylinders it shouldn’t be that much of a problem.
Our Extendomatic arm raises and lowers using a pair of HUGE cylinders attached to the Strongback and Extendomatic. We need different pressures for that and for the Spinny Grabber, so are using two pneumatic regulators, a primary and secondary.
We are using coding and buttons on our controller to be able to raise or lower the Extendomatic to different heights so we can put cones on any of the nodes. We can also put cubes anywhere.
We are also ready to switch out our masonite pegboard electronics board for one made out of lexan. It will not be as high on the robot as the masonite one. We also used a scrap of masonite for a belly pan/pneumatics board. It will be replaced with plywood to add some weight to the chassis to stabilize it. We may yet add more ballast.
The pneumatics on the belly pan will also be covered with a plywood box for protection. And that will also function as ballast.
We have a couple of designs for a pneumatic brake to keep us from rolling off the charge station. It will use the Rubber Bumpy Things (RBTs), also known as Bumpons. We hope to have that done (and find a place to mount it) by the end of next week.
Meanwhile our Pit Crew - has practiced setting up our pit. All but 2 of our team members are new to FRC and have never seen a pit, let alone set one up.
Well, that’s all for this week. Three weeks from today we get on the bus to go to our first event in Tallahassee. We are nervous but excited, and are sure we will have everything done before then!