The high speed pinion is 4.71:1 until the REV ratio kit is release which highest is 3.56:1
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Yep, weâre at the highest in the base kit right now on NEO Vortexes (~19 ft/s). Once we get the speed upgrade kit, weâll put on the Extra High 5 ratio, which gives us a free speed of around 25 ft/s.
Keep in mind that the heavier your robot gets, the slower it accelerates. Also, when you gear it to a higher free speed, it has less torque to accelerate. Weâre aiming for a light robot, but it will still be 2-3x heavier than that drivebase, so the cycle speed may end up being slower than what is shown in the video.
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Is this the correct part for the wheels that are being tested? (Other than the zip file retaining ring)
edit: Link: Onshape
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Thatâs the wheel that we drove on yesterday. After seeing how hard the TPU is, pretty much any of the designs on that onshape link should work very well if you get the right TPU.
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It is. But as @Eliot said any of the designs (should) work but thatâs the exact ones they used in the video. The only major difference is that it uses infill as the as the âspringâ and how the tire is retained. Unknown if the retaining matters with a much stiffer TPU.
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are you guys still thinking about a dual intake?
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Do you have details on âright TPUâ?
Someone whoâs name rhymes with Garrison pointed me towards 85A, but your test data suggests 95A may be more grippy.
Idk Iâm probably a little biased though
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Yeah, some of us have a bunch of filament around already and have been discouraged from ordering more because âyou have a problemâ and âweâre worried about youâ so I was hoping to use some of the TPU I already have on hand.
Sounds like 95A is the right hardness.
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My data also suggests 95A is more grippy. This is because the spikes take more force to deflect in the carpet as the durometer increases, hence more grip. The only problem is you end up getting closer to âhard plastic studsâ as you increase durometer.
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In my head, the stiffest filament that is still legal will get us the best results on traction and lifetime.
Some other teams have printed these wheels in 80A TPU, and they had less than stellar lifetime.
There is a BIG variance in TPU filament durameter between vendors.
Weâve tried Micro Center (Inland) TPU as well as Matterhackerâs build series. (Sent to us by @Technologyman00 ) Matterhackerâs build series is significantly stiffer, and weâre going to print more wheels out of that filament.
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Why stop at hard plastic? Why not go for thousands of short wire bristles? Maybe wrap one of these around the wheel?
/s
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I havenât tried the MH filament, but the black Inland TPU seems to be stiff enough. The prints so far have come out pretty well with one exception, that I donât have the supports well enough to fully separate them. Iâm going to attempt a different pattern to see if that will be easier, but if any have Prusa Slicer support settings for TPU that are working well Iâd be interested to learn more.
The inland TPU had a very bad lifetime actually driving the bot. The Matterhackers TPU has a much better lifetime.
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We (mostly) have a robot!
(Disclaimer: this post was written on 1/19 and has been delayed)
We had a meeting last night. A team meeting. The type of meeting where we walk in with multiple competing plans and walk out with a unified vision for the robot.
A weeks worth of snow days and cold days lead to us spending a lot of time staring at our computer screens and imagining the robots we could build. We outlined four contender robots we were investigating for the 111 2024 robot, and we had THOUGHT we narrowed it down to two. Robot Type 1 (Double Jointed arm on a lift) and Robot Type 2 (Launcher on a lift with U-Turn amp mech) both showed a lot of promise, but ultimately, neither is what we will be pursuing for 2024.
Robot Type 1 (Double Jointed Arm on a Lift)
Major Pros
- Simplifies DoF required to complete a Note scoring cycle (1, shooter tilt)
- Storage of notes in shooter allows for late drive decision making of speaker vs. amplifier scoring
Major Cons
- Entire arm shoulder must be mounted to elevator carriage, presenting huge packaging/rigidity problem.
- Trap climbing requires storing lift for majority of match at mid point of travel, raising up to plant arm, then pulling drivebase up to allow extension over what would normally be the 48" height limit.
- Compounded DoF can lead to positional repeatability issues.
Robot Type 2 (Launcher on Lift with U-Turn Amp Mech)
Major Pros
- Moves most of robot mass very low for majority of mass.
- Eliminates bending of the note before launching.
Major Cons
- Lots of moving mass on elevator may slow certain robot actions.
- Multiple compounding DoFâs can lead to inaccuracies in shooter positioning.
The Bot Weâre Building
After much review of both robots, we eventually settled on talking through these robots, trying to build a new design from basic functional descriptions up to a unified robot concept. The new design attempts to combine the best of both worlds.
This robot would use a UTB to feed up into a feed system. This feed system can pass the note out either end. A lift would raise the feed system up to the amp scoring position or keep it at itâs lowered position and feed backwards into the shooter. The shooter is attached to the drive base and can tilt up/down to âbendâ the note path through the robot and hit all of our required launch angles.
The climb system would be a pull down hook on an arm coupled with a follower wheel mounted to the lift. Deploying the feed up to the top of travel would also deploy the reaction wheel above the bottom of the stage core, enabling a climb.
This robot take both the minimal moving DoF benefits of the double jointed arm robot, and marries them with the integrated feed/launcher system of the launcher on a lift robot.
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Check our our first (ever) appearance on the OA show!
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Build has started!
This Saturday, we kicked off manufacturing on both the 24W and 24P drivebases for 2024! Batch cutting both drive bases like this lets us cut both swerve bases in about 4 hours of machine time while minimizing setups and tool changes.
111 Base
112 Base
Additionally, the print farm (aka printers at mentorâs and studentâs home) kicked off mass producing the TPU grip wheels for our MaxSwerves. Orange matches the trademark polybelt pretty well!
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Why use TPU wheels and not tread?