March 10, 2015

Wheel Pods

Team 467 has been refining their 4 wheel independent wheel-pod design for the last five years. This year’s design is compact, robust, and easy to construct. They are designed to be removed and reinstalled with a single screw.

Each CIM-powered wheel-pod uses a two-stage belt drive with an overall speed reduction of 12.5:1 to the stock AndyMark wheel. The pulleys are all custom CNC-milled, and the pod frame is water-jetted out of 0.375” aluminum stock.

The 4 wheel independent steering uses a BaneBots motor for each wheel-pod to control rotation angle. The wheels are programmed to protect the power and sensor leads from becoming too twisted. This setup allows for a very maneuverable robot, with a number of unique drive modes that include:

Robot-aligned drive
Field-aligned drive (using gyroscope data)
Strafe mode (drive perpendicular to robot front)
Revolve mode (rotate around a fixed point in front of the robot)
Spin in place

In this video, Jack and Aayush show how to assemble the team’s 2015 wheel pod design. 

Custom Wheelpods

Driving

The 16 teeth pulley is on the Cim motor which then connects to the 48 teeth pulley with a belt. The 48 teeth pulley is on the same steel shaft as the 18 teeth pulley which then connects with a belt to the 75 teeth pulley which is on the same aluminum hex shaft as the wheel. When the cim motor starts running each pulley starts turning and when the largest pulley turns, the wheel turns because the largest pulley is threaded to it. Also all of the shafts turn because they are attached to bearings and are secured that way with retaining compound.

Wheel Pod

  • CIM motor
  • Top and Side plates – water jet cut 0.5” Aluminum
  • 16, 18, 48 and 75 tooth CNC made pulleys
  • 5mm, 64 tooth timing belt
  • 5mm, 92 tooth timing belt
  • 6” AndyMark Plaction wheel
  • AndyMark hex hub
  • 1 custom Steel shaft 2.625 inches
  • 1 aluminum hex shaft 4.3 inches (0.5″ diameter)
  • 4 recycled soda can tops
  • 3 10-32 bolts
  • 12 various washers
  • 5 1/4-20 bolts
  • 4 bearings

Steering

  • Banebots motor with 126:1 ratio gearbox
  • 5mm, 92 tooth timing belt
  • Novotechnik RSM28 multi-turn rotation sensor

Come check out our CAD files

2017 swerve drive wheelpods preliminary CAD files