Steering

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Pushcarts - Steering
How has it been done before?
Questions and Decisions
The best solution will take into account:

  • How far the driver has to move their arms or legs to change direction safely?
  • How much force the driver needs to apply to change direction safely? How strong does the driver need to be?
  • Is the direction of movement for the driver intuitive (i.e. does it make sense)? Does the driver move the steering mechanism the same way as the cart needs to go, or the opposite way?
  • Can the driver steer with one hand and apply the brake with the other?

The biggest question is:

How will you supply the effort to the front axle so that it is an effective lever?

Suggestions and Choices
There are four basic steering mechanisms from which to choose:

  • ropes - relies on strength of arms
  • joystick - uses levers (see the model)
  • steering wheel - like in a normal car
  • feet (how safe is this?)
  • other steering mechanism you have found

How does each one work?

The pivot joint on the front axle is the weakest link in your pushcart!

The pivot joint needs to be made of a strong material (steel bolt or pin for example) because it has to both support the weight of the cart and driver and survive the effects of inertia when you try to change the cart’s direction of movement.

Try This
Compare the effort required at different points on a lever by doing a scientific fair test. This will help you decide where you should attach your steering system to get maximum effect with least effort.

For each type of steering option you have available you should list the choices you have. Write down the 'strengths and weaknesses' for each choice to help you make your final decision.

Test your steering options for:

  • ease of use with available hands and/or feet
  • strength
  • durabilitysafety for working with it
  • safety for broken pieces

For Teachers
Steering your cart (PDF 570KB/2 pages)

If you have any choice of the type of bearings and bushes to use for your pushcart you will need to remember:

  • Thrust bearings are good for turning - they still actually work at an angle.
  • Needle bearings and bushes are not thrust bearings. These don't work as well in turning situations but are great for the straight.
  • Ball bearings are good in most situations.
  • Conical tapered roller bearings are fabulous if you can get them and work out what they do. These are used on all cars.
  • Perhaps you could visit an engineer, mechanic or supplier who could show you the differences between these types of bearings.

Support Materials developed by engineeringLinks at UTS

 

 

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