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Commercial Off the Shelf Components - Answers

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  • Commercial Off the Shelf Components - Answers

    Please be sure to read the Game Manual and the responses to other questions in the forum before posting. Thank you!

  • #2
    Originally posted by RedfishRobotics
    Linear Actuator Kits

    Some suppliers have begun offering "lift kits" to assist with the lander latching challenges (auton & end game). The kits in question generally use the rotation of a lead screw to move a lead screw nut attached to some linear extension such as an aluminum extrusion (80/20, Xrail, Etc.).

    Q1: Does a kit that provides both rotational movement and X/Y movement (as described) violate RM02, which limits COTS kits to "A single degree of freedom".

    Q2: Is the described kit more or less legal if it it also includes an otherwise FTC legal motor or servo to rotate the lead screw?
    A1: Yes

    A2: The legality of the motor has no effect on the overall legality of the actuator.


    • #3
      Originally posted by FTC14534
      Linear Actuator - Revised

      Q: I know there is a question and answer regarding the COTS systems from Servocity, but I wanted to know if all of the parts are purchased separately, can they be used for the team to build their system? If so, will there be any proof required during the robot inspection to verify these parts were purchased separately?
      A: The Game Design Committee has had a lot of inquiries regarding the use of linear actuators for this year's challenge. Normally we encourage teams to design and build their own mechanisms to solve the game challenges but on occasion we have allowed the use of COTS kits that provide additional capability to teams without ruining the robot design experience (for example: the TileRunner kit). Due to the overwhelming response from the FIRST Tech Challenge community, the GDC has re-evaluated the use of linear actuator systems with regard to Rule <RM02>. After discussing this issue with numerous resources and evaluating the effect on game play, the GDC has decided to allow the use of linear actuator kits.

      There are a few conditions however:
      1. This is a one-time exemption and not a blanket change in Rule <RM02>.
      2. The linear actuators are limited to one direction of motion, no X-Y actuators.
      3. The linear actuators must use legal parts, the the motors used must be from the allowed motors listed in Rule <RE09>.

      The GDC would like to thank all the teams that provided positive, helpful input to the decision-making process.
      Last edited by Broadway Joe; 10-11-2018, 11:12 AM.


      • #4
        Originally posted by FTC9808

        Q: Are small turnbuckles like the ones below legal for use as lift cable tensioners?

        A: Yes


        • #5
          Originally posted by FTC9819
          Linear rail and Actuator Kits

          Q: We would like to ask about the legality of the following:

          1- Is the cascading rail design from Servo City is legal to use?

          2- Is the servo kit from Andymark legal to use?

          3- Is the Linear kit V2 from REV Robotics legal to use?

          4- Is the servo linear it from Servo City legal to use?

          A1: Yes
          A2: Yes
          A3: Yes
          A4: Yes


          • #6
            Originally posted by FTC13438
            Tank Treads

            Q: I don't see tank treads on either the legal or illegal parts list. Can my kids use these? We wanted to order the Tetrix Max Tank Tread Kit. Is that legal?

            A: Yes, tank treads are legal but they are still subject to Rule < RG01>.


          • #7
            Originally posted by FTC4634
            Shock Absorbers

            Q: Would these type shock absorbers be within the allowable parts? They show as NOT being oil filled and NOT pnuematically charged.

            A: In a shock absorber, a moving piston forces air (or oil) through a series of small holes thus slowing the motion of the piston and absorbing energy. This restriction results in compressing the air and raising the internal pressure. Rule <RG01> does not allow devices that use compressed air in any form. Therefore this is not a legal COTS.


            • #8
              Originally posted by FTC12611
              Ball Caster

              Q: Does this product violate "single degree of freedom"?
              A: This ball caster is a legal COTS part.


              • #9
                Originally posted by FTC12611
                Ball Caster with Bearings

                Qoes this product violate "single degree of freedom"?

                This has ball bearings and can move in omni directions.

                A: Yes this ball caster is a legal COTS part.


                • #10
                  Originally posted by FTC11479
                  Servo Blocks

                  Q:Is the Servo City servo block part # 637118 for quarter scale servos iegal?

                  A: Yes, this is a legal COTS.


                  • #11
                    Team Marker made from Minerals

                    Q: We have a question about materials we can use for our team marker. We would like to use either a Gold Mineral or Silver Mineral as a part of our team marker. Is that allowed?

                    Thank you![

                    A: There is no rule restricting the use of Minerals as building materials for a Team Marker. However, it must be obvious to the Score Trackers and other Field personnel that these Minerals are part of the Team Marker, and not scored Minerals. If there is any confusion at all, the team will be asked to replace this Team Marker with a more suitable one.


                    • #12
                      Originally posted by FTC15167
                      Gate Latch

                      Q: Can we use a fence gate latch from Home Depot ( in our Rover Ruckus robot?
                      A: Yes, this is a legal COTS part.


                      • #13
                        Originally posted by FTC13670
                        Phone Holders

                        Q: Hello, we wonder if a smart phone holder would be legal to use in our robot, something like this

                        A: Yes, phone holders are legal.


                        • #14
                          Originally posted by FTC10674
                          AndyMark Gearboxes

                          Q: Are AndyMark gearboxes permissible in Rover Ruckus? I am thinking specifically about dual motor versions: AM-3448 and AM-3908. Product links are here:, and
                          A: Yes, this is a legal single speed gearbox per Rule <RM02>.


                          • #15
                            Originally posted by FTC3595
                            Heim Joints (rod end bearing)

                            Q: Are purchased heim joints, AKA rod end bearings, AKA rose joints a legal component? Here is an example:

                            A: Yes, a rod end bearing is a legal COTS part.