Week 2: Wheelsets and Chassis

Overview

Now that we’ve made some wheels, we need to attach them to something, and those things to things.  We’ll cover wheelsets, wheel configurations, and chassis.

 

 

Chassis

A chassis is the base frame of a vehicle or other wheeled object.  Wheels, axels, and propulsion are typically mounted in some way to a chassis.

 

Wheelset

We touched on wheelsets already, two wheels fixed to an axel.   Great for going straight or on a track.  This configuration does not turn well.

Arguably one of the easiest wheel configurations that can be made.  Two wheels, two hubs (if necessary), and an axel.  The trickiest part of using a wheelset will be how to mount the axel to a chassis.

 

 

Two wooden wheels, two 1/4″ shaft collars, 1/4″ shaft, one U Bracket Chrome (or U Bracket)

If you need to make the bracket hole bigger to accommodate an axel or bushing, use a drill press and a proper set up.

A more expensive but precise method is to use pillow blocks also known as mounted bearings.

 

Free Spinning Wheels

Free spinning wheels can have their own individual axel or share with another wheel.

Two free spinning wheels, four shaft collars, an axel

Two wheels, two bearings, four shaft collars, an axel

 

Four Wheels, two bolts, two nuts, four washers, block of wood

 

Two wheels, two shoulder screws, a chassis to screw into

The trick is the diameter of the shoulder of the screw needs to fit the bearing snuggly or allow a non-bearing wheel to spin freely.

Free spinning wheels and axles, everything is off the shelf.

 

Small-Space Plastic Clamp

 

DIY Handmake RC Car 4 pcs 370 Gear Motors

Wheel mounted to geared motor, motors are mounted to acrylic chassis with motor mounts.  Each wheel has its own propulsion.

 

Casters

How you mount casters depends on the design of the caster.

 

Three or Four Casters with Posts, three or four shaft collars, chassis.

Laser Cutter Files

 

Combine Wheel types

Two Free Spinning Wheels, Two Casters

Two Free Spinning, One Caster Ball

Boe Bot

Wheelset and Free Spinning Wheels

Vantomme E12 & M10 Chassis

 

 

Breadboarding

Breadboarding mechanisms is usually accomplished with two parallel flat plates, separated by standoffs or spacers.  This method can work well for chassis.

Two metal plates, three screws, three nuts, three spacers, three 1/4″ bushings.

More Elegant Breadboarding

 

Steering

Two part chassis that swivels at a point.

Laser Cutter Files

Full Lock occurs when wheels turn and bang into the chassis.  This can be avoided by wide wheel base or a raised chassis.

 

TV Eye Car

 

Tiny Bot

 

Omnibot

 

Steering Plate and Rod Ends

 

Off the Shelf Chassis

Motor Robot Car Chassis Kit with Speed Encoder wheels and Battery Box

MakerFire 4 Wheel Robot Chassis Kits

2WD RC Car Kit

 

 

 

Non Traditional Chassis

Homemade Chassis

 

Stick Chassis

 

 

CityCar

 

How Differential Steering Works

 

In Class Prototyping

Using our new hardware (and anything else we can get our hands on) we will create chassis and wheelbases.  We’ll take 30-40 minutes to roughly prototype and flesh out ideas.  We will then discuss what we think, next steps, and possible tools and techniques.

 

In Class Demo

If there is time, we’ll vacuum former some half sphere molds.

 

Assignment

Wheelhouse, you will be creating rigid, well-crafted chassis and wheelbases.

 

 


Related Reading/Viewing

The Complex Reality

Adventures in CNC Robotics

RC4WD Chassis

RobotShop Chassis Kits