No announcement yet.


This is a sticky topic.
  • Filter
  • Time
  • Show
Clear All
new posts

  • #46
    Extending the Power Wires for the Wi-Fi Module

    Originally posted by 2010FTC0747
    Rule <R11> (c.) states that wires may be extended. I would like to clarify if that includes the power wire for the Wi-Fi module as it is too short. As the rule only specifies 'Motor power, power and encoder wires'.
    FTC 747
    Extending the power wires for the Wi-Fi module is allowed, provided that the same gauge wire is used as the original power leads.


    • #47
      Originally posted by 2010FTC2803
      Is it acceptable to use a pin/socket style connector, but that connects multiple conductors in a single plug. We need a method to quickly disconnect the cable harnesses between custom sensors on robot and the custom circuit board. A single connector would be much nicer than snap plugs on each of the 20+ wires.

      A: As long as all of the wiring is done within the realm of the prototype board, the pin/socket connector is accepted. Please remember all the other rules in wiring and using the proto-board (only power is supplied from the NXT, etc.).


      • #48
        Originally posted by 2010FTC2803
        At a recent event we burned up two 12V tetrix motors when our robot lost communication with FCS. There was significant damage to the actuator drive system, and we would like to use inline fuses to (hopefully) prevent this situation in the future. We have a design constraint that prevents the use of the tetrix "fused" motor connectors due to how close two motors are back-to-back, we have to solder the wires directly to motor tabs. Ideally, we'd just splice in the appropriate sized fuses into the motor power harness, but in post #28 you ruled that COTS fuses were not allowed.

        As an alternate approach, can we buy the approved tretrix fuse protected power cable and splice the fused section of wire into our motor harness under the cable splicing and extension provisions of R11c / R11e.

        A: Yes, you may purchase the approved TETRIX fuse protector power cable (Part #: W736465) and use its wire under those splicing and extension provisions.


        • #49
          Originally posted by 2010FTC0747
          Just want to confirm this, but how do we know the guage size for the wires leading to the Wi-Fi Module? It is not stated on the Game Manual. Also, are snap plug connectors like those used to connect the battery to the wire coming from the servo controller allowed if we use them to connect a wire coming from the Wi-Fi module and another from the Servo Controller! We have to do this as our Wi-Fi module wire recently became damaged due to the gears on the robot. The wire totally went through the pinch point on the gears.

          A: The gauge is 18AWG. The use of insulated snap plug connectors are allowed. See post #21 below.


          • #50
            Securing power cables to TETRIX DC motors.

            Originally posted by 2010FTC4080
            We used to solder power cables to dc motor terminals directly. At a recent event we lost two motors. We want to secure electrical wires to channels. So we are planning to switch to using Tetrix DC Motor Power Cables but worried these may come loose during match and motor may lose power. What are the approved means of securing these cables to dc motors? Thanks in advance
            Teams can use any material allowed by rule <R5>. For example, rubber bands, electrical tape and non-metallic cable ties are a few of the options.


            • #51
              Butt Splice Connectors

              Originally posted by 2010FTC1000
              Could a team use butt splice connectors to splice two wires together?
              Yes, butt splice connectors are allowed.


              • #52
                Originally posted by 2010FTC3599
                Our team is using the prototype board with a remote sensor attached to a pivoting arm. To test this arm we used the standard 20 gauge wire and quickly discovered that the wire was broken internally by the flexing of this joint. Would we be allowed to splice stranded heavier gauge (18-16) wire between the 20 gauge used to connect to the prototype board and the wire connecting to the sensor?

                A: Yes, this is allowed.


                • #53
                  Are crimp connect with receptacle and plug allowed?

                  Originally posted by 2010FTC3237
                  Our team is soldering the wires to the motors directly and it's hard to replace bad motors. We're thinking about using plugs like the ones on the 12v battery to the switch to make the process easier. Are crimp connect with receptacle and plug allowed? Here's an example picture:

                  The part referenced in the post is not permitted. See post #21 in this forum thread (Robot Electrical) for a similar part that is permitted.


                  • #54
                    &quot;Y&quot; cables for power distribution

                    Originally posted by 2010FTC2843
                    In post #36 you allowed splices to make "Y" cables for motors. Are we allowed to create "Y" cables for power distribution to the motor/servo controllers either by soldering or the allowed insulated snap plug connectors (post #21)? This would be similar to the suggested power wiring for the Samantha Unit.


                    Yes, this is permitted.


                    • #55
                      Tamiya Connectors

                      Originally posted by 2010FTC3237
                      Are we allowed to use Tamiya connectors on our robot?
                      The Tamiya connectors that are used with the TETRIX battery pack are the only allowed Tamiya connectors on the robot. Additional Tamiya connectors are not permitted.


                      • #56
                        TETRIX Fuse-Protected Motor Power Cable

                        Originally posted by 2010FTC3785
                        We are using fused wiring for our motors and every once in a while- gremlin like- the motors go on the fritz and it seems that the in line fuse is clicking on and off which makes the robot go crazy- so to speak. Do the fused wires have a limited life? We have 2 robots and -1 robot has 6 motors and has more wiring issues but our other robot is prone to these intermitant electrical problems? Any suggestions?
                        The manufacturer does not specify a “lifespan” of the part, nor do they provide an expected number of cycles that the part can reliably be operated.

                        The way this part works is that once it goes into a “trip” condition, a self heating property keeps the part open circuit until all current has been removed. In our case, that means bringing the power to the DC motor to zero (0). Once this happens, the part will cool down to the reset condition.

                        If a motor is very quickly being brought back to stall level, or continuously operated close to the trip point max, there could be a “chattering” affect because the thermal device is being operated “hot”. So, in the case described in the post, it sounds like it is doing it’s job of protecting the motor.

                        In general, if a motor is experiencing this chattering, we suggest allowing time after a trip condition for the thermal stall sensor to cool down before re-applying heavy load conditions to the affected motor. Or, use the stall sensor power cables just for testing and prototyping of the robot during initial design and build. Once the design and software has been worked out, switch to the standard power cables.