FTC WEST MICHIGAN KICKOFF FTC CHASSIS BUILD AND WIRING TIPS (AND MORE…)

AGENDA: INFORMAL DISCUSSION TO INCLUDE…  Basic stuff  Wiring Tips  Build Tips  Design  Open Q&A

START WITH…READ THE MANUALS  Simple… read the manuals…  Highlight / write down requirements  Reference with questions  Use the forums  Wiring Guide available from FIRST

MODERN ROBOTICS FIRMWARE UPDATES   Who is affected:  Any controllers purchased prior to this season  How to update  Visit Modern Robotics site  Need to send in  Quantity discounts (bundle with more teams)

ROBOT WIRING: POWER POLES  Battery Connectors  Come with a Tamiya connector  Replace these with an Anderson Powerpole Connector  Use the Ultasonic Welded Housing from Powerwerx  Doesn’t void Modern Robotics Warranty  Prevents reverse polarity by incorrect assembly  Use the correct Amp rating (30A will work for all FTC parts)  All Housings are the same, size.  Terminals are sized different for amp requirement for wire sizes.

ROBOT WIRING : POWERPOLES  Tools: Use the correct ones for the correct results  Crimpers  Powerwerx: $39.99  ConnectorPro: $29.99 (  Tie or Lock them together  Zip ties: $ pennies  Use Retention Clips (Powerwerx): $0.47ea  Use a Insertion Tool (Optional)  Powerwerx: $9.99

WIRING TIPS: MOTORS  Tetrix Motors  Tape the end cap first  Tape around motor and wire to retain  AndyMark Motors and Encoders  Integrated power cable doesn’t fall off  Encoder cable can pull out  Use a zip tie or tape around the motor to retain and prevent stress on these

WIRING TIPS: CABLES, WIRING, AND PORTS  Fasten all wires and cables  Prevent wires from moving into pinch points (e.g., between two gears or into a movable mechanism)  Prevent entanglement with other Robots  Prevent strain on wiring components  Provide easier access for maintenance.  When using zip ties, don’t overtighten. The wire casing should not be crushed.  Don’t wrap / bend tight

WIRING TIPS: OTHER STUFF…  Other tips  Static Electricity is everywhere on the field.  Protect where you mount components.  Protect your frame from static discharge.  Change batteries every match, charge between  Have at least 2 batteries. It is well worth the cost!  Have spare fuses:  Tetrix Batteries In-Line (15a?)  PDM (20a)  Tape over any open ports on your controls  Have batteries checked, if possible. Some teams have battery testers and will be happy to test them.

BUILD TIPS: ROBOT SIZE  Design within the 18” x 18” x 18” box  Make the frame and height short by at least ¼” to ½”  The robot can expand larger during game play  At inspection the robot will need to fit into an inspection box.  Build an inspection box, add a lid, and use it to safely transport your robot.  Sizing Box Plans: brary/ftc/instructions-for-building-sizing-boxes.pdf brary/ftc/instructions-for-building-sizing-boxes.pdf

BUILD TIPS: FASTENERS  Fastener Recommendations:  Use Lock nuts (#6-32 ~ $2.67 at McMaster-Carr for 100)  Use steel set screws in collets  Deeper hex hole = less wrench stripping  Deeper hex hole = ability to tighten better  Tip styles – Different tip styles can hold better but may damage the shafts. Use these only if you need the extra bite  Use Alloy Steel Screws in critical areas  This can improve the shear strength by several hundred lbs  Shafts – McMaster Carr 3/16” shafts work great but don’t have a flat for set screws. We prefer a 4140 material for high strength.  Also, shafts from Servo City are a better quality  The Tetrix material is soft. In some cases, if using Socket head Cap Screws, you may want to use washers to distribute the load and prevent bolt pull-through.

BUILD TIPS: MATERIALS  Tetrix  Matrix  Actobotics  Custom Build The choice is your! It is really your preference and comfort level (plus cost resources). Why bring this up… FIRST has used and “pushes” the Tetrix kit during registration. The rules have changed and now you have a LOT more options. Each option has it’s own advantage and disadvantage. Teams need to come to the conclusion on how to build on their own.

BONUS: SERVO CITY ServoCity (Actobotics) 25% discount to FIRST Teams More options than Tetrix / Matrix Free Parts with newsletter Videos to lean from Return unused parts

BUILD TIPS: TETRIX BEAMS To provide more mounting options in the Tetrix components, double drill the hole patterns Align 2 Tetrix parts together offsetting so that the holes overlap where there are none Use a fastener on each end of the part (long parts center also) to hold together. Using a drill press or hand drill, drill holes where none exist to create additional hole patterns. Great way to also get students working with tools and having tasks to perform. Idea and picture for Double Drilling found on the Cougar Robotics (FTC 4251) website.

BUILD TIPS: STRONGER DRIVEN SYSTEMS  Design for strength:  Use on both sides to stabilize the system and improve strength  Counterbore to sink heads flush to save space  Requires special C’Bore tool (approx. $25)

DESIGN: HOW STRONG IS YOUR MOTOR  Don’t let out the magic smoke!  Look at motor specifications and use as appropriate AndyMark NeverRest 40 Performance Specs, mounted to AndyMark dyno: Max Speed (under load of dyno): 129 rpm Stall Torque: 396 oz-in Time to Failure at Stall: 2 minutes, 54 seconds Motor Case Temperature at Failure: 190 degrees F Lifting a 2lb (32 oz) load 15” from the motor would incur 480 oz*in of torque

OPEN Q&A

FTC WEST MICHIGAN KICKOFF FTC CHASSIS BUILD AND WIRING TIPS (AND MORE…)