Motors and Servos - Answer Thread

[Pierluigi Collina]

Linear Actuator

As an off the shelf part, is the linear servo https://www.servocity.com/hda10-2 Allowed in robot builds?

Answer: As sold, the above servo does not meet the requirements of being able to be powered and controlled by any of the alllowed Servo Controllers and is therefore not allowed.

[Broadway Joe]

RE10 - Linear Servos

Hello, I was looking to get a new autonomous button pusher for our team. Would this Linear Actuator we were looking at buying be within the Robot Inspection Rules if we were to get 2.

Here is the link...

http://www.robotshop.com/en/firgelli-technologies-l12-100-100-12-i.html#description

Thanks,
Graveyard Shift
#11825 MHS Robotics

A: Option R, using the 3 wire RC servo connector and limited to 5 V is legal. The other versions are not allowed.

[Pierluigi Collina]

Non-Powered Motors

Would unpowered DC motors used for purely aesthetic/decorative purposes count towards the <RE09> 8 motor limit?

Thanks,

FTC Team 8391, W-Prime

Answer: Yes. All motors on the robot count towards the 8-motor limit, regardless of their current usage status.

[Broadway Joe]

RE09 - Spare Motors

Hi,

This is a strange question. When our team was at a qualifying tournament, the lead inspector told us that since we had 8 motors on our robot, that if by chance we had an extra motor on our robot cart, not on the robot, when we left the queuing area to compete, we would be disqualified. He went so far as to say, if we even left a spare motor in the queuing area on the way to compete, we would be disqualified. It this true? And if it is, does this extend to servos and batteries as well? We always carry a spare battery on our cart just in case.

Thanks in advance,
Team 11703

A: Rule <RE09> refers only to the motors that are part of a legal Robot. Teams are allowed to bring as many spare motors, servos, batteries, etc. as they wish on the Robot cart.

[Pierluigi Collina]

Switches to disable servos

Our servos are moving when the robot is powered up. This behavior appears to be caused by the servo controllers momentarily writing a voltage to the servo port at power up. Unplugging the servo controller then, obviously, doesn't fix this behavior. The only fix that has been suggested is to put a switch between the servo controller and the servo itself. Is this legal if the switch is put on an extension cable such that neither the servo nor the servo controller are modified?

Answer: No. This usage of switches would fall under <RE17> Additional Electronics and is not allowed (i.e. it is not a sensor and not connected to the Core Device Interface Module)