Vex IQ Car Update 1

If you were at Vex IQ worlds this year, you may have passed by a booth near the REC store with a vex IQ car in it, along with a six-pistonIMG_20190428_0931174 IMG_20190609_1717587 radial engine. I am the builder and owner of that car, and I want to share a couple of updates about it. The changes will be in order from smallest to biggest, based on how the car has changed between worlds and now.

  1. Secondary differential mounts
  • shortened the input axle
  • changed gears to increase speed (I had torque before, but it increases speed)
  1. Chassis
  • changed supports
  • created system for axle routing
  1. Steering system
  • changed the sway bar from a 4-bar lift to a single bar
  • added bump sensors to allow for auto-resetting of the steering system
  1. Suspension
  • complete redesign
    a) Shortened length or 4-bars
    b) added one weak shock on top of the two strong shocks per wheel
    c) changed shock mounts
    d) replaced some pins with metal axles
  1. Engine and primary differential
  • complete redesign
    a) decreased number of motors from 8 to 6
    b) increased torque in gears between differential and motors
    c) designed a differential lock system
    d) moved motor up to prevent diff-lock system decreasing ride clearance.

Current Version - 5.0
Worlds Version - 3.2
Major Changes

  • Reassign ports to account for hardware changes
  • startup task to reset steering system

Minor Changes

  • Adjusted steering amount


  • All-wheel steering and Crab steering both result in crab steering

Proposed changes for 5.0.1

  • fix crab steering bug from 5.0
  • readjust steering amount

This is really cool, thanks for sharing!

How did this project originate? What are your plans for the build going forward? Are you planning on making more documentation available (e.g., close-up photos, written descriptions, source code, CAD models)? I think looking at a complicated model like this in some detail could provide insight into omde advanced techniques. (also, it would be cool)


I have a model in LDCad Vex, with a set of generated instructions using LPub 3D, but it is several versions out of date.


As for plans, I need to see what needs a brush up once I get this thing moving again, because I am currently missing four Universal Joints (part 228-4419). However, one main idea is to substitute the vex IQ battery for one that holds more power, as to increase the driving range of the car