The latest and greatest iteration of my swerve design. STEP and 2019 SW files available here.
Previous iterations and versions of swerve that I have worked on for reference:
2020 Summer? Swerve
2019 Winter Swerve
2019 Offseason Swerve
2018 33 Buzz XXIII Swerve
2015 Offseason Swerve
2015 2451 PWNAGE Swerve - Most design credit to @Kevin_Ainsworth, inspired by @Aren_Hill
2014 2451 PWNAGE Swerve - Most design credit to @Kevin_Ainsworth, inspired by 3928 and @Aren_Hill
This module is mostly the same as the Summer 2020 iteration, but has some key differences:
3.75" wheel compared to the previous version of 3" wheel
4.25" L x 4.25" W x 8.09" H compared to the previous version of 4" L x 5" W x 7.4" H
3.25lbs compared to the previous version of 3.45lbs
Frame tube size is now 1.5" tall. This kept the height lower on the module to offset some of the growth from the larger wheel, and also helps reduce chassis weight by having smaller tube. 1.5" x 1" x 1/16" 6061 is available from onlinemetals, or 1.5" x 3/4" x 1/16" 6063 tube is available from Eastern Metal Supply. How the frame tubes integrate with the module is shown in the CAD model.
Polycarbonate cover added to sheild the inside faces of the module so everything is now fully enclosed.
Experimenting with TPU 3D Printed wheel tread insted of traditional rough-top tread. Alternate wheel design could easily be swapped in for rough-top. Working on testing of this TPU tread concept currently, inspired by some design principle work pioneered by @Kevin_Ainsworth and 2451 regarding the specific geometry of the tread shape, and inpired by 3357 to try printed wheel tread.
All of the following information is the same as the previous version, with the exception of the bevel gears which is now an 18:45 1.25 module bevel gear stage. This change was to maintain the same output speeds as before with the larger wheel size.
Drive ratio is a 18:45 1.25 module bevel gear ratio, first stage off the motor is 10/11/12:28 20DP spur gear. Optional 9:30, or 13/14:26 also available.
Drive Speeds (free speed):
12.16fps (09:30 first stage)
13.27fps (10:28 first stage)
14.59fps (11:28 first stage)
15.92fps (12:28 first stage)
18.57fps (13:26 first stage)
20.03fps (14:26 first stage)
Steering ratio is a 5:1 (5.23:1 actual) UltraPlanetary Gearbox, followed by a 16:86 GT2 belt stage using a 94T belt. Overall ratio of 28.1:1, ~391rpm free speed.
Steering position is determined using a Lamprey Encoder mounted to the top of the pod. Local control to get to position can be done using the encoder on the n550.
Module is symmetrical, allowing for same parts to be made for left and right hand modules.