The latest iteration of my swerve design. previous versions and more information on previous development can be found here.
STEP and SolidWorks files available here.
Bill of Materials can be found here.
Main changes on this version were the following:
Replaced the Lamprey Encoder with the REV Through Bore Encoder. This was to improve reliability and have a simpler calibration process.
Re-arranged the geometry so that the module was symmetrical about the corner plane, so that left and right side modules are the same.
Went to a 2.5in ID 3.0in OD bearing from the previous 3x3.5 to get the module even smaller, lighter, and to get the wheel closer to the frame perimeter. Because of the smaller bearing, the belt reduction for the steering is smaller, thus a second UltraPlanetary stage was added to ensure there is still enough reduction.
Switched back to a 3in wheel. I wanted this version to really be the ultimate small module I would ever actually make. I likely will make a ~4in version, either one that uses the same upper parts and just swaps the bevel gears and fork assemblies, or a completely separate module design.
4.20 W x 4.20 L x 6.9 H
The first stage of reduction for the drive of the wheel is a 10/11/12:23T spur gear reduction. This is followed by an 18:45 bevel gear reduction. Drive speed options (in free speed) are:
13.39 fps (10T Pinion)
14.72 fps (11T Pinion)
16.06 fps (12T Pinion)
The steering ratio is two 3:1 Ultraplanetary stages, followed by a 16:72T GT2 belt stage using an 87T belt. Overall ratio of 37.6:1, ~293rpm free speed.
Steering position is determined using a REV Through bore Encoder mounted to the underside of the top plate underneath the NEO motor, and wired to the RoboRio. Local control on the Spark MAX can be done using the encoder on the NEO 550.
Module is designed to utilize 1.5in x 1in box tubing, with notches cut in the side around the areas of the turret of the module. Details about how this is done can be found in previous iteration threads linked at the top of this post.
To remove the wheel, the two screws that mount the fork that does not contain the bevel gear are removed, and the screw going through the wheel shaft is removed. Once those 3 screws are removed, the wheel and fork is able to hook out, while the other wheel fork that keeps the 18T bevel gear in place remains.