pic: BeachBot Pseudo-Crab drive, partially assembled

[Bob Steele]

Originally Posted by s_forbes

I think I understand where Paul is coming from; we had the idea at the beginning of build season to attach the bumpers and trailer hitch on a turntable so they could be moved relative to the rest of the robot, but threw it out because of rule R18.B:



It seemed obvious to us at the time that the design would not pass inspection... based on the logic we were using at the time, 330's design is questionable, as is any robot with a swerve drive to some degree. It's kind of a hazy subject that will be left open to the inspector's interpretation.

I certainly hope there are no inspection issues though... it's a cool design!

I am curious to find out why you would think that the Beachbot's design does not comply with this rule?

"The trailer hitch is rigidly attached to a fixed location on the robot."

In their design this is true...for it not to be true you would have to have a non-fixed location or a location that is changing on the robot.

Just because the wheels turn under the frame does not make this false..

If one were to define "fixed location" on the robot in the way it is apparently being discussed.... you would have to have NO moving parts on the robot at all...

Relative motion is relative motion...

What is moving? One can only define that when one picks a frame (no pun intended) of reference. The Beachbots have chosen to use their outer frame as that frame. It is fixed... the wheels rotate below it...rigid attachment and fixed location... sounds ok to me...

I would be happy to argue this rule with an inspector...
(I am a physicist so frames of reference come naturally to me...)