FRC 6328 Mechanical Advantage 2020-2021 Build Thread

Very cool to see this - we’ve been working on a similar drop down buddy climb. Our isn’t up and running yet but it is cool to see another team testing a lift system. We’re running in the kit of parts chassis and toughbox gearboxes so we’ve been working around those with our buddy bars.

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This is something that we found as well during our testing. We also played with “pulsing” one side on and off, or simply running the two sides at different speeds. Bottom line, the ability to have independent control of the two sides of the indexing belts felt too important for us to mechanical join them together to save on PDP slot usage.

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I’m not sure if my eyes are deceiving me or not (view angles in CAD can be strange sometimes), but it appears as if your intake will not be able to bring balls into your robot because of the distance between your rollers and your frame. It doesn’t look like it accounts for the width of your bumpers at all (unless you plan on having 3-4” compression on the ball lol).

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you’re not far off, we’re squishing the ball a bunch to intake it, we believe this helps get the balls off the ground as soon as possible to avoid running over the balls.

Edit*
here’s a video of our prototype using this geometry

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Packaging this has been incredibly difficult and we’ve had to make a few big trade offs to get these arms in the frame, hoping it’s worth it!

We also did a small amount of testing do similar things and I totally agree, hoping having the ability to independently control will with worth the extra PDP slot.

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Heavy CAD day today, biggest changes were increasing the height of the front of our hopper to be inline with the top of the bumper and decreasing the width of the robot by .25in so we aren’t at the 120" limit. Also sat down and started dropping electronics into the CAD to get an idea of where we stand. We knew this would be big challenge given how dense the robot is but we’re decently happy with where we stand.

Also continued work on the telescoping arms which should be done by Wednesday/Thursday. That’s the last big part of the robot.

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This is very validating. Add my thanks to the pile

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Been busy the last few nights just finishing up CAD work, building our the pbot drive train this Saturday and getting it running and finalizing the entire robot CAD(finallyyyyy).

We wanted to take all our prototypes and see the entire ball path working together before hitting the go button on some metal so the students took some time to mock everything up.

Final Product

Video of it working

While we’re waiting on some metal to get cut for our gearbox plates we decided to print a few on our MarkForged out of Oynx with Fiberglass Inlay. We’re going to drop them into our practice robot frame and see how well they hold up this weekend. I think they came out pretty slick and feel very solid.

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Sorry for the lack of updates, it’s been crunch time lately and we’re feeling the pressure. Here’s an updated screen cap of our finalized CAD minus climber arms(still in development) and intake(which is being swapped for a fold down instead of a slide out to increase simplicity).

Intake and Climber Arms should be done next couple of days. All sheet metal for the robot is getting cut and bent Thursday/Friday.

Here’s some assembly progress pictures for the PBot.


Competition Hopper gonig together

Look how small this is! So insane!

Big shout out to REV Robotics for all the awesome products.

New team banner!

Finally we started working on code base for our shooter. Super excited to see this mocked up this far and the ball path working consistently. First set of shots is just testing ball path, second set is from 25ft away, third set is from initiation line.

*yes the shooter isn’t completely mounted to the frame and because of this we’re experiencing some serious recoil and movement in the shooter. Tonight we will hard mount the shooter better to hopefully increase our ability to consistently hit the exact same spot every time.

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A little insight into how we make our sheet metal. Planning on doing a full writeup for teams this summer about how to best utilize a sheet metal sponsor. Here’s our shooter metal all ready for assembly.

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I was wondering how long each stage of your lift is and how tall it gets when fully extended? It looks really compact and short!

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How are you liking the ultraplanetaries? We have really liked the Neo 550s so far

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Have you tested your current climber setup? We have a very similar design with telescopic arms. 2 arms, one on each side of the robot. We tested the climber today and are experiencing issues when the hanging bar isn’t leveled. The robot is only hanging from one hook and deflected the one arm quite a bit.
because of our test today, we are trying to come up with a different way to set up our telescopic arms.

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We have a very similar setup, so I am interested in hearing more about this. Could you elaborate on the problems you faced/post a video?

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Didn’t get video today since it was a bit of chaos during testing.
But I created this sketch to try to explain.
Because the hanging bar isn’t leveled and the telescopic hooks are being pulled down at the same rate, the robot will continue to be orthogonal to the ground which will prevent the hook that isn’t engaged in the hanging bar to ever make contact with the unleveled hanging bar. Plus, since the telescopic arms are not centered on the robot, the weight of the robot in the opposite side of the arm hook that is engaged falls towards the ground and then created a deflection on the arm that is hanging on the bar.

Hope this explains it a bit.

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Peep the 190 shirt on Maddie. Still waiting on my 6328 shirt trade-back though.

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ill make sure she gets that to you

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This is shaping up to look like quite the elegant robot. Can’t wait to see the fruits of the team’s efforts in action at Northern CT!

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Total reach is around 67 inches, will need to look at CAD model to get heights on each stage. Its longer than it looks likely because the arms will be tilted backwards to give us a few extra inches and will extend straight up when we’re ready to climb.

Nope.

We’re likely going to be limited to climbing in the very middle with each of our arms on either side of the center cap thing. It was a trade-off for us to increase simplicity. This system of climbing in the middle also enables us to balance easier when we’re picking up a second robot.

Appreciate the kind words, see you at Northern CT!

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