African Handcart: Innovative Designs 1

[Josh87]

Hello,

I am currently working with waste pickers in East Africa to pilot various designs for the standard hand/push cart, commonly used for the transport of goods and waste. At the moment I'm looking for specific input for the recommended PSI for tyres for different surface areas and loads. I'd like to calculate how to measure and fine tune this process. Specific details of the handcarts are below. A photo example of the handcarts is attached.

Handcart Carrying Area

W: 0.64
L: 1.82
H: 0.39

Wheel

0.57 wheel diameter, standard rubber car tyre

Average Holding Capacity/Weight

300kg

 

[StoneCold]

What about starting with something close to a pedicab.

 

[MikeHalloran]

The maximum inflation pressure for a tire is molded right into the sidewall. Why not start with that, or a few percent less, to provide a little safety factor for old tires?

Reducing the inflation pressure makes the tire ride more smoothly, but makes it harder to push on any normal (Western) road surface.

... probably also including deep sand. Off-roaders here commonly reduce tire pressure in sand, but it's done to reduce the ground pressure, not to make it easier to push.
... and off-roaders also carry compressors with which to restore proper pressure, something that's probably not in your budget.

For a test program, you'll need a compressor, a tire pressure gauge, a representative pushcart, a selection of typical surfaces, and a force gauge with which to measure the needed force. ... or just a calibrated arm.

... or maybe a rope, a snatch block, a tree, and some weights.






Mike Halloran
Pembroke Pines, FL, USA

 

[MartinLe]

What problem are you trying to solve? Are the handcarts too hard to push? Tyres fail? ...?

 

[MikeHalloran]

Star for MartinLe.

Josh, you are trying to improve a design that has been evolved over decades by severe economic pressure; there may not be any fat remaining in such a simple design.


Mike Halloran
Pembroke Pines, FL, USA

 

[Artisi]

Following on from MikeHalloran, probably he design is now refined as to what is the best compromise - the only improvement I can see that is likely to assist is a reduction in the overall weight - lighten up on the timber used - might only save a few kilos/ pounds but a save is a save when using human power.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)