Building Bonanza: Two Weeks Until Qualification Meets!

It's been six weeks since kickoff, and we only have two weeks left until our first league qualification meet. If you've been keeping up, we aren't done building our robot quite yet, which means we are very behind where a typical team would be this close to competition. A team that's been working seamlessly all season would have their robot fully built and programmed and be fine-tuning everything for their autonomous program and working out little kinks. We aren't the perfect FTC team, though, so we are a little bit behind!

Given this, we made tremendous progress this week with building our robot. We were able to adjust the claw and attach the rotating platform, control hub, battery, and carousel spinner onto the robot. Let's walk you through exactly what we did.

At the beginning of the week, we attached the giant gear we 3D printed last week onto a ball-bearing rotating apparatus (it's the kind of thing usually used on a lazy susan). This bearing allows the gear to be affixed to the robot and still be able to turn freely, but without a shaft down the middle because that's where we need to attach our lift and claw to pick up our game pieces. We attached the giant gear and its bearing setup to a few extrusions on top of the robot and put the motor and smaller gear on and set it up to turn. From what we can tell with a quick power on to the motor, the giant gear-platform spins just as we expected. There is a little bit of friction on the bearing, so it makes a bunch of noise, but it's nothing our motor can't handle. The next step in this area of the robot is to attach the lift, but, unfortunately, we don't have it quite completed, so we aren't able to fully complete attaching the claw to the robot.

The bearing on the gear-platform is noisy! But it spins great.

The two gears are mounted on the robot with the motor.

Speaking of the claw, we had a few more problems with the claw this week, again. The biggest of which was that the claw didn't fit within the 18 inch dimension restrictions for FTC. We held it up in the spot that it would roughly go on the robot since we can't attach it yet, and it was just a smidge beyond 18 inches! But a smidge is too much, so we had to fix it. We cut the extrusions on the two little arms of the claw by about 3/4 of an inch, but that wasn't quite enough and we couldn't cut off any more or the claw would be too small to pick up any of the freight. We then reconfigured the servos that move the claw so that they aren't perpendicular to the claw and taking up some of the space inside the gap where the claw has to sit. We rotated them 90 degrees to have them take up less space, and we moved the mounting extrusion to hover a little bit above the claw where it will be out of the way for sure. We also had a little bit of trouble with our rubber bands. The rubber bands are what actually pick up the pieces of freight, so they need to reach all the way down to the floor to touch the freight and pick it up, but there were a couple of things in the way. The place on our robot where the claw goes just happens to fall right on top of some of the extra bits of the axles for our wheels on the drivetrain. We could have cut the shafts a little shorter, but those are really hard to cut because they are made of steel, and we had another idea. Instead of suspending the rubber bands on either side of the extrusions for the claw's arm, we decided to attached them below the extrusions using a couple of brackets and screws to anchor them in. This worked great; while the extrusions of the claw still can't go past the axles of the wheels, we can still pick up the freight because the rubber bands extend below the axles and to the floor.

The original claw design goes beyond 18 inches.

Measuring the robot to 18 inches where the claw belongs.

The new claw design for servos and rubber bands.

The new claw fits well in the robot and within the 18 inches

The new rubber band design goes around the axle for the wheel and the extrusion stays above it.

We got one more thing finished, or at least mostly finished, on our robot in terms of building. We attached the carousel spinner, which is basically a couple of flexible and grippy flywheels turned by the servo. We just had to make sure they were attached at the same height as the carousel so that they could turn it and deliver the ducks to score points. This wasn't overly complicated or difficult to do, but it's a step in the right direction for finishing this robot quickly. We tested the movement briefly, but we don't have all the wiring or programming done yet, so we can't really test it all the way.

The carousel spinner is attached on the robot!

We also were able to attach the battery and control and expansion hubs onto the robot. We attached them in a way that will hopefully be out of the way, but we aren't totally sure about that yet.

Battery, expansion hub, control hub (not pictured) and switch are all on the robot.

Programming is coming along too, slowly but surely. We have the drivetrain coded almost completely and it works nearly flawlessly. The other programs in our robot are rough drafts at this point because we don't have the hardware fully assembled. Obviously, none of these programs have been tested yet either. We have a general outline for our autonomous program too, but it also hasn't been tested on the robot.

I hope you all had a very happy Halloween, and I am really sorry that this post is up a day late. Next week's blog post will be up as usual on Sunday. Follow us on Instagram (@batteriesnotincludedftc) so that you can get notified when we post on the blog. We post exclusive pictures and videos of our robot on Instagram, and they usually get posted as it's happening, unlike the blog, where the information is a few days behind the live action. That's not to say you shouldn't read the blog posts! We provide so much more detail on the blog than on Instagram, but you'll get some sneak-peaks at what's coming in the blog from our Instagram posts. See you next week! (or sooner on Instagram)