View Single Post
  #9   Spotlight this post!  
Unread 18-05-2014, 22:37
asid61's Avatar
asid61 asid61 is offline
Registered User
AKA: Anand Rajamani
FRC #0115 (MVRT)
Team Role: Mechanical
 
Join Date: Jan 2014
Rookie Year: 2013
Location: Cupertino, CA
Posts: 2,224
asid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond repute
Re: Fastest drivetrain in Aerial assist?

Quote:
Originally Posted by Dunngeon View Post
ONLY if you have a low gear/two speed gearbox. Your acceleration will be impacted significantly with a top speed of 26FPS, which may mitigate the perceived higher top speed (not useful if you never get there). Personally, I would only design up to 24 theoretical, because beyond that number most drivers seem to struggle controlling the robot.

Top speed isn't the only thing to consider when choosing gear reduction. We factor in Driver Ability, Game Requirements (open field, field with obstacles) , and Robot factors (such as weight) when choosing the reduction.

This year we were geared for 18 FPS, and achieved 16 actual due to a robot that only weighed 107 pounds w/ battery and bumpers. We thought it was a good harmony between speed, and torque (we run single reduction). If we were to run a 2-speed, the actual would likely be bumped up to 18-20 FPS actual because we can now have a low gear (5-9 FPS) for pushing
Of course, driver training is extremely important. That's why I suggested a software limit for speed at first and later.
Personally, I think the game doesn't matter as much as driver training. The drivetrain should be what the driver can handle; pretty much every game in FRC in the past several years has required speed.

If you used PWM control to the motor, wouldn't it technically accelerate faster with a software limited top speed? If you don't stall the CIMs, that is. I feel like that doesn't work out, but can anybody explain why?

From what I've seen, acceleration can probably be mitigated as a problem with a 3 + 2/3 cim per side gearbox. (heheheh)
Does anybody know what the maximum speed it is physically possible to go on an FRC robot? Assuming you want to drive for 10 seconds before the main breaker blows with a 100lb robot.

Last edited by asid61 : 18-05-2014 at 23:01.
Reply With Quote