Chief Delphi - 2005 Drivetrains

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Re: 2005 Drivetrains

It is important to be able to control your speed to help maneuverability, however you do need some pushing power. One of the biggest things is for the drivers to be able to control the robot well.

Re: 2005 Drivetrains

Quote:

Originally Posted by Greg Needel

this is not possible because you wont have the traction to transfer that force to the floor.... kinetic force = (coefficient of friction)*(the normal force)

since the coefficient of friction can;t be more then 1 and your normal force is essentially the weight of your robot (force that acts perpendicular to the surface)

therefore your max force can not reach 340 ft-lbs

i would recommend recalculating your theoretical force to a more reasonable value around the max weight of your robot but even that will be overkill and you will just end up spinning your tires

Greg, you're right about the wheel slip being the limiting factor, but with interlocking surfaces or certain combinations of materials, μ can exceed 1; it's a convenient approximate upper bound, but it isn't a physical limit. (See here.) Some FIRST teams have empirically determined the coefficient of friction of rubber tread on carpet to be around 1.2; it all depends on your particular wheels.

Re: 2005 Drivetrains

Additionally, that is probably the torque at stall. You should not be able to stall your motors (or even get close) in low gear.

Re: 2005 Drivetrains

Just a thought perhaps the only factors aren't speed and torque, but say... manueverability? I think the 'strategy on the fly' aspect of the game will reqire a large amount of agility(not the same as speed) and reliability from the robots to be able to adapt with the strategy.

Going pusher won't guarantee that you'll hold an area against a fast bot, and being fast won't mean that you'll outfox the pusher bots. Having a transmission doesn't guarantee the best of both worlds. The great thing about this years game I think is that with three-team alliances and 9 goals strategy becomes a lot more dynamic. Pushers and nimble bots both seem to have their place and use this year.

Just make sure that your particular strategy does not require more speed or torque than your bot can handle.

(btw i'd like to point out that speed and manueverability are not the same)

Re: 2005 Drivetrains

Quote:

Originally Posted by Xufer

i think its going to be hard to get all three robots behind that line it looks like such a small area.

Go look at a scaled drawing of the field, and put 28" by 38" into that scale, and then compare the size of the robot to the space between the "endzone" goals.

Re: 2005 Drivetrains

Quote:

Originally Posted by Tristan Lall

wow....i guess this just goes along with the saying "you never stop learning" all of my professors always just told us 1 was the max and while you can get a coefficient higher then 1 it still wouldn;t constitute a drive train with theoretical torque of 320 ft-lbs... thanks Tristan for the education