As of Summer 2016, ready for the 2017 FRC build season the Swerve and Steer module has had a number of improvements. 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 software control. Additionally the 12 tooth CIM pinion/drive shaft now has a wider slot to allow for a 2mm key to lock the shaft to the motor.
The Swerve and Steer module is an all-in-one swerve gearbox AND steering module. The wheel propulsion is powered by a CIM Motor, while the steering torque is managed by a PG71 gearmotor. Both of these motors are mounted to a main motor plate, which can easily be mounted to extrusion frame or other structure.
The PG71 has an encoder on the back side of the 775 motor, which can help keep track of the steering location. In order to use this method of closed-loop encoder tracking, use a 3/16" allen wrench to ensure that the motor plate, bearing plate, and gear late are all aligned before operation. Alternatively, there is a location to mount an absolute encoder (this absolute is not included). Both motors are included in the low price. This module is shipped fully assembled.
Drive Gearing & Ratio:
- 12 tooth spur gear is driven by CIM Motor
40 tooth spur gear is driven by 12 tooth gear
20 tooth bevel gear is co-axial with and driven by 40 tooth 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
Steer Gearing & Ratio:
- 660 rpm
- 11.5 ft/sec (using the included 4" HiGrip wheel)
- 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
Overall Gear Ratio: 1:1.2 (over-driven)
- Steer Speed: 90 rpm
- 1 CIM 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 explination can be downloaded here, http://files.andymark.com/FRC1640_2011_PivotDriveLibrary.zip
- Mount Plate Length: 6.5"
- Mount Plate Width: 5.5"
- Overall Height: 12.04"
- Weight: 9.4 Pounds