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Commerical Off the Shelf Components - Answers

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  • Commerical Off the Shelf Components - Answers

    Answers to questions about Commercial Off the Shelf Components (COTS) can be found here.

  • #2
    Originally posted by FTC12611
    Question 1: Is the gripper kit from ServoCity legal to use?

    Question 2: What if we redesign the claw and 3D print, but reuse the servo bracket in the kit, is the modified module legal?

    Answer 1: The referenced gripper kit from ServoCity is not allowed. Commercial off the shelf gripper kits are specifically called out as illegal in the Game Manual Part 1, rule <RM02>.

    Answer 2: In general, it is legal to remove a single degree of freedom part from a commercial off the shelf multiple degree of freedom mechanism and use the single degree of freedom part in a Robot.

    It is legal to use the servo bracket (flat plate with through-holes) from the ServoCity gripper kit in a Robot. It is also legal to add Team designed and fabricated parts to the servo bracket to build a gripper or other mechanism. However, it is against the spirt of rule <RM02> to use the servo bracket and make copies or slightly modified versions of the remaining unused gripper kit parts and build a gripper for the Robot.


    • #3
      Originally posted by FTC6747
      Subject: VEX Linear Slides
      Q: Can we use VEX linear slides?
      A: Yes, the VEX linear slide kit is a legal COTS part.


      • #4
        Originally posted by FTC9978
        Subject: Single Degree Of Freedom

        Q: The rule: <RM02> Commercial Off The Shelf Parts - Teams may use Commercial Off The Shelf (COTS) mechanical parts that have a single degree of freedom. A single degree of freedom is a system whose motion is defined just by a single independent co-ordinate.

        1 Does this only apply to COTS or does it apply to anything the team uses.(3D printed and designed by the team)

        2 If the team would like to design and build a robot arm, with two segments with a hand grabber at the end (maybe even have fingers with joints), is that considered a single degree of freedom because they are separate but connected at the elbow and wrist joint with a servo?

        A1: Rule <RM02> refers only to COTS parts. Teams may design and build mechanisms with as many degrees of freedom as they wish.

        A2: A team designed and built robot arm as described is a legal mechanism.


        • #5
          Originally posted by FTC5598
          Subject: Servocity Cascading X-Rail Slide Kit

          Q: Is this a legal COTS part?
          A: Yes, this is a legal COTS part.


          • #6
            Originally posted by FTC7253
            Subject: Mirrors

            Q: Rules restrict directed outbound light (lasers and LEDs with mirrors). We were wondering...
            Can we use a mirrored surface as part of the incoming light path for the phone camera?
            A: Rule <RE12> disallows the use of mirrors for directing robot based light sources. Mirrors used to direct an image to the camera in the robot controller are allowed.


            • #7
              Originally posted by FTC1999
              Subject: Servocity Gearbox with Potentiometer
              Q: <RM02> states that Examples of allowed single degree of freedom parts Single speed (non-shifting) Gearboxes.

              Are the ServoCity pre-assembled servo gear boxes legal, given that they include an external potentiometer (see for instance They are pre-assembled, and seem like nothing more than en enlarged form of the standard internal servo gearbox.
              A: Yes, these gearboxes are a legal COTS part. However, the potentiometer is still subject to all the other rules regarding electrical devices and sensors.


              • #8
                Originally posted by FTC4634
                Subject: Casters

                Q: Do either or both of these violate the intent of the rules on freedom of motion on purchased hardware? IE too many degrees of freedom? There are differences of opinion on the intent of the build rules on our team...


                A: The ball caster is a legal COTS. However, the caster wheel has more than one degree of freedom and therefore it is an illegal COTS part.