The wheel propulsion is powered by either a CIM Motor, a Falcon 500 Brushless Motor, or a NEO, while the steering is managed by a PG71 gearmotor. Both of these motors are mounted to a main motor plate, which can easily be mounted to your robot frame or other structure via the 0.5 in. hole pattern around the perimeter.
There are three encoder options available:
- "PG": The incremental encoder on the back side of the PG71. This encoder can be used to determine steering angle provided that all the modules start facing forward.
- "MA3": An MA3 absolute encoder and associated hardware included. The user has the option of 5 mounting locations for this encoder.
- "Lamprey": A Lamprey through bore absolute encoder pre-installed and pre-calibrated into the module.
- 1/2020 FRC 2020 Season Refresh
- Choice of CIM or Falcon 500 motor
- Choice of either PG, MA3, or Lamprey encoder
- Thrust needle bearings replace bushings supporting the robot weight.
- Gear plate redesigned for more supporting surface area
- Ball bearings replace bushings on the 12T input gear shaft.
- Bearing gear redesigned to accommodate this bearing as well as the Lamprey encoder magnet
- Drive axle is captured with tapped ends to increase yoke rigidity.
- Yoke redesigned to accommodate hex spacers sizes
- Drive axle has tapped ends
- 11/2019 Standardized CIM pinion to 1/2 in. face width with 3/8 in. of centered tooth engagement
- 9/2019 Removed unused hole and adjusted thickness on bearing plate
- 8/2019 The motor mount plate has been widened to make mounting to box tubing frames easier and the lightning pattern has been redesigned. Note this change means they no longer 100% drop in replacements for old modules. See CAD for details.
- 8/2019: The PG71 now uses a 1/2 in. hex shaft as the 3/8 in. hex PGs are being phased out.
- 1/2019: The PG71 now uses a 3/8 in. hex shaft and the gear mounted to it has access holes for easy tightening and removal of the gearmotor.
- 7/2017: The keys used to transmit torque from the CIM were widened to prevent it from becoming dislodged.
- 7/2017: The collar clamp on the CIM pinion was replaced with one of higher quality to improve clamping force.
- 7/2016: The absolute encoder, am-3308 now has mounting locations to give a 1:1 gear ratio to the module via the 40 tooth encoder gear for easier programing.
- 7/2016: The 12 tooth CIM pinion now has a wider slot to allow for a 2mm key to more securely lock the gear to the motor.
Drive Gearing & Ratio:
- 12 tooth spur gear is driven by CIM or Falcon 500 Motor
- 40 tooth spur gear is driven by 12 tooth spur gear
- 20 tooth bevel gear is co-axial with and driven by 40 tooth spur gear
- 40 tooth bevel gear is driven by 20 tooth bevel gear
- 4" HiGrip Wheel is co-axial with and driven by the 40 tooth bevel gear
- Overall Gear Ratio: 6.67:1
- 660 or 800 Max Wheel RPM (depending on motor selection)
- 11.5 or 13.5 ft/sec (depending on motor selection)
- 48 tooth spur gear is driven by PG71 gearmotor
- 40 tooth spur gear is driven by 48 tooth gear
- Lower portion of module pivots directly with the 40 tooth gear
- Max Steer Speed: 90 rpm
- 1 CIM or Falcon 500 motor for Driving
- 1 PG71 for Steering
Team 1640 has some example code for driving a swerve system. Their Cheif Delphi post can be found here, https://www.chiefdelphi.com/media/papers/2704. The Library and explanation can be downloaded here, https://files.andymark.com/FRC1640_2011_PivotDriveLibrary.zip
- Motor Input: CIM,Falcon,NEO
- Motor Quantity: 1
- Weight: 8.3lb
For teams that do not have a lot of CAD/CAM ability, AndyMark always gives us an ability to try new things. The preassembled swerve modules, let us get a testBot going is less than one weeks. Going forward, we want to go to CAN bus to eliminated a bunch of control wiring. We already had 4 Neo500 motors so we swapped them into the CIM locations. Only issue was the motor leads and a 1/4 nut wanted to be in same place, but it worked ok. I have a Neo550 motor that I would dearly love to mount on the PG71 gearbox, but I may not be smart enough. This will get rid of all the PWM + encoder cables. Enough whining... Your modules did exactly what we wanted. You got us a working swervebot with the least amount of cost and fabrication effort. Thanks