FRC drive train

[first_newbie]

What is shake in terms of drive train in frc? Sorry for all the questions.....

[MrForbes]

Questions are good! no need to apologize.

It might help if you can provide some more context for your question. I dont know what "shake" is...could be a few different things...with several different causes.

[GeeTwo]

The only example of a shake drive I'm aware of was the "Harlem Shake" routine at this post.

[first_newbie]

http://www.chiefdelphi.com/forums/sh...38049&langid=2
References of shake on the aforementioned thread

[EricH]

In that particular context, I believe it's referring to the ability of a robot to hold a straight line without swerving all over the place.


Typical characteristics of an FRC drivetrain (no descriptions): speed, traction, number of speeds (and spread of the gear ratios), wheelbase & trackwidth, overall type (of which there are several: tank, swerve/crab, mecanum, omni, H/I drive, and the various subtypes of butterfly drive), and for tank drives the drop of the center wheel.

Non-typical characteristics: shake.

[GeeTwo]

Originally Posted by first_newbie

http://www.chiefdelphi.com/forums/sh...38049&langid=2
References of shake on the aforementioned thread

This referenced the "rocking" motion of a drop center drive chassis in the pitch axis. In drop center, there are three (or more) pair of wheels, and the pair(s) in the center are positioned a bit lower (typically 1/8") below the line connecting the front and rear axles. This drop allows the robot to have the advantages of a short wheelbase for purposes of being able to turn, and those of a long wheelbase for purposes of not falling over forward or backwards. The cost is a bit of rocking motion as the robot shifts from one axle to another. For some games, this is of little or no consequence, but for others where the robot may be very tall, have a long arm, or be aiming at a goal with a tight vertical tolerance, the amplification of that 1/8" can be a problem. For more detail on why drop-center, see this classic white paper.