Robot Speed Rules

[Marc S.]

Originally Posted by Dusk Star

To the best of my knowledge, there is not a speed limit other than to not cause an unsafe situation, and those imposed by Newton. Remember, the court isn't actually that long, and I have never heard of a team gearing a robot for more than about 15 fps.

973 was geared for a little over 20(free-speed) in 2011. It's not uncommon to see teams shoot for that range, however it greatly depends on the game. For instance in 2010, it was very uncommon to see teams in the 16ft/s+ range because of the large bumps in the field. In 2008(as was mentioned before) a lot of teams geared high because it was basically a speed game. 148 even geared for 30ft/s, however later re-geared their robot to a slower speed.

jalmos, I highly recommend that if your team is shooting for higher speeds then you definitely use a 2-speed gearbox. The super-shifter from AndyMark is a good choice.

[Billfred]

Originally Posted by Marc S.

jalmos, I highly recommend that if your team is shooting for higher speeds then you definitely use a 2-speed gearbox. The super-shifter from AndyMark is a good choice.

Yes and no--this is generally a good idea in many standard drivetrains, but it is not something I'd advocate a team undertake with 12 days to ship day without a full appreciation of the issues.

This is JVN's mechanical design spreadsheet, which many teams have found exceptionally useful. Run your numbers and see where you stand--once you get much past 10 feet/second, you're requiring a bit more skill. (And mind that acceleration will be much more common this year thanks to the dividers and bridges; the faster you gear the robot, the more current you'll draw on each launch and while pushing. You're going to push.)

If you're using the kit drivetrain and you decide your speed is not what you want, I'd suggest changing your wheel sprockets (or output shaft sprocket, but double sprockets are harder to find). This is much easier than integrating all-new gearboxes, but it has the above-mentioned tradeoffs.

[Mullen]

While there might not be any ruling about the max speed of your robot, be aware that high speed ramming is generally frowned upon. Don't get me wrong, it does happen. If you are zipping across the field to make a defensive stop, I typically encourage the drivers to take the speed down a notch just before interacting with another robot.