Over the pandemic, we were able to learn a lot allowing us to make a robot much better than we thought we ever would be able to do pre-pandemic. We tried out numerous new things this season and for the first time ever, we have won events, qualified for DCMP, and qualified for worlds off of robot performance.
Features of this year’s bot:
SDS mk4 swerve at l2 ratio
Full width intake resistant to numerous collisions during competitions
Adjustable hood ranging from 82 to 58.5 degrees capable of shooting from 1 foot behind the fender up the terminal
14:10 reduction + low inertia on the shooter for a fast recovery time
9 second traversal climb from contact with mid bar
Reduced width of 25 inches to make more space on traversal bar
5 ball auto firing the last shots with 3 seconds to spare
Thanks for releasing your CAD. I’m interested in your fastening technique of the polycarbonate links on your intake. They appear to have a hex shaft of some sort and a pulley tooth profile. Any further detail you could provide is appreciated.
The polycarbonate links were attached using hex shaft that was tapped on both ends and then retained using 1/4-20 screws with washers. Thin spacers were placed between the bearings and the polycarbonate to prevent the inner inner race from dragging.
We put two motors on the telescopes and geared them to pull 40a current each and move at ~2ft/sec loaded and ~2.5ft/sec unloaded. However, when climbing, they are slowed to 70% power in code as otherwise the inertia can pull the hooks off the bar. The full speed is used when raising the telescopes. There is little reason to not gear motors to climb as fast as possible as mechanisms can easily be slowed down in code without swapping out the gearbox, but not sped up. Funnels on the telescoping hooks and the collapsible pivot hooks increase the margin for error when climbing. The pivoting pistons are 1.0625 bore cylinders to retract will enough force quickly, however, this is likely overkill. Placing the climbers near the center of gravity makes the mid to high bar transition happen without any swinging so swinging is only a problem when reaching up to traversal.
The climb sequence is semi-automated. The second driver has a button to automatically bring the telescopes to the correct height to hook onto the mid bar. After the mid bar is contacted, the bot is raised manually until the pivots attach to the mid bar. This is done manually due to a design error with the fleet angle of our spools preventing 100% consistent winding which is required for automatic retraction. The second driver then has another button which tips the bot and extends the telescopes to the right height in just one button press. Retracting the pivots is done manually due to automatic retraction being inconsistent. And the process is repeated with the bot being raised and then transferring to traversal.
The climb sequence can be seen here, line-up starting at 25ish, contact with mid bar at 20sec, and scored at 10sec.
Apart from that, the climb isn’t really anything special, its just a well optimized lego 2 climb.
