2023 is the year of light weight robots. Let’s list out ways to add weight to the robot, besides bolting the heaviest piece of scrap you have to it.
Backstory: We are 90% finished with robot wiring and mechanical assembly and we currently weigh in at 61 pounds. We are hoping to change some things on the robot to finish with an inspection weight of 100 pounds. Below are some things our team and other teams can do to both add weight, and lower their robots center of gravity. Some of these only apply to west coast drivetrains.
Steel Belly Pan
Steel Hex Shafts in the Drivetrain
Steel Gears in the Drivetrain Gearboxes
Solid Steel Frame Rails
Steel Plate Frame Gussets #35 Chain Drivetrain
Steel Drivetrain Sprockets
Solid Steel Bumper Frame Supports (R410)
Steel Brackets on Bumpers (R408)
Steel Angle Bracing On Bumpers (R408)
Heavier wheels on the drivetrain
More wheels on the drivetrain
1/4" Hardware vs. #8 or #10
We were practicing with two 10lb dumbbells zip tied to the front our robot. We were fairly certain that this wouldn’t pass inspection, so milled two steel “swerve protectors” that each weigh in at about 8-9lbs. Worked great. Not tippy at all and driver said they even improved robot drive performance.
Don’t skip leg day? Also, more reps, less resistance.
Jk. We had a parent run out to a sporting goods store and pick up 2 8 pound weights to use as ballast in the bottom of our robot in order to help stop it from tipping over. Between first and second comp we have cut the robot down from 48 inches tall to ~ 20. We plan to take it to the vet to weigh it, and add ballast to get us closer to our goal weight.
We attached 4 bar stock in our KOP frame. 2 front and 2 rear. It smoothed out the drive capability of the bot. It added about 20 pounds to the overall weight. We were also looking at steel plates for the belly pan…about 1/4" plate. That hasn’t happened yet. Still an option.
She wasn’t pushed pushed around like week one…she held her own.
We saw a lot of high COG bots running…and falling.
We had some scrap 1/4 in steel sheets, so we cut them to size, sandblasted the rust off, painted them (to prevent rust going forward), and attached them to the bottom of our robot on the outer most ends (to help with inertial rotation). Got us another 20 lbs, which was closer to our goal. The lower down and further out the weight is, the better for anti-tipping.
Lead weights (like dive weights) are also allowed, but only if they’re coated.
We stopped by a local metal place and picked up some 5”x1.25” steel bar stock out of the offcuts bin. Had to cut it down a bit (took a long time on our little horizontal bandsaw) but now we have 30lbs of reasonably low profile ballast on the robot for about $30 (the actual segments were ~25lbs each). We also have a couple of small 10lb bars for whenever those might be appropriate.