AfriCart – a handcart for Africa

ED302 – design & technology

06.0 Production – Flowchart

Flowchart

Wood was selected from the wood store – two planks of pine. I first planed & edged these using the planer/thicknesser and then split them longitudinally using the table circular saw.

From the wood room the wood was now transferred to the workshop – here the wood was planed to remove any coarse edges and cut into the carts constituent lengths:

A. 2 x 38″ (4″ x 1″) – these would make up the “bow” and “stern”  of the cart.

B. 4 x 38″ (4″ x 1″) – these would form the longitudinal sections in which the wheel sits.

C. 8 x 25″ (4″ x 1″) – these would form the slatted floor of the cart’s load box.

D. 1 x 50″ (4″ x 1″) – which would later be sawn into: 2x 50 (2″x1″) to make the sides of the handle.

Stage 1:

Planks B were planed to size and 3″ tenons were cut into either end: 1″ to pass threw plank B with 2″ clear.

Planks A were planed to size and then 4 x 2″ mortices cut into each of them. Planks B would fit into planks A to leave two 4″ channels either side. Planks B were then routed on the box side to fit the box floor.

Planks C had 1/2″ tenons cut into each end so that they could fit into the routed B planks and so form the load boxes floor.

Planks D were planed and then drilled to fit round cross-members.

Stage 2:

africart_stage1_complete copy

A & B planks were assembled and the corners clamped to ensure that everything was “square”.  A top and bottom were chosen – either side of which you can see the channels in which the wheels would be clamped.

Stage 3

africart_stage1_front

The complete frame was disassembled. Holes were now drilled halway down the B boards – these would hold the bicycle wheels stub axles. In order that the bikes metal spindle did not wear away at the wood and eventually become loose – I fitted copper (a more durable material may have to be found – but since the metal spindles are not rotating, copper should be fine.) sleaves (boxing) into the inner holes (boxes) – this little trick I actually picked up from an account of the Mormons using hand carts in America in 1856. During the opening up of America, people pushed west with whatever they could. Not everyone could afford a covered wagon or the draft animals to pull it and so the majority of goods were carried on hand carts rather like the ones seen in Section 02 Research.

In pioneer wheel terminology, the “box” is the smooth, round, tapered hole inside the hub that slips over the spindle on the end of the axle. It was best in pioneer days to press a tapered cast iron sleeve into the box to provide a more durable surface. The metal insert is called the “boxing”. Brigham Young instructed them to “line the inside of the hub with good sole leather for boxes”. What is a “thimbleless axle”? The spindle is the bearing surface on the end of the axle. it was best to cover the wood with a protective thimble made of metal. This thimble is more often called the skein. In desperation, and far from their point of departure, the handcart service technicians protected the wooden spindles with metal from their tin-plates, kettles and buckets or screwed on a piece of iron to prevent the
wheel from wearing away the wooden spindle. The spindle needs the most protection on the bottom side because the load is always pressing the spindle DOWN on the inside of the rotating hub. We have seen several iron skeins on wagons, where the bottom of the skein is completely worn through to the wood, while the top of the skein is still very thick and usable

Mormon Handcart Pioneers

africart_copper_sleeve

In the picture above you can see the outer or load box side of the copper sleeve – the inner side had to be flanged with a hammer in order that it remained in place.

Below is a picture of the completed frame with the wheels in place, now the load box floor boards can be inserted.

africart_stage2_complete

Stage 4

Once stage 3 was complete, the bed of the cart’s load box could be fitted. Initially I was going to fit each board using mortice and tenon joints, however this seemed rather long winded and so I decided to rout a channel in the B boards to hold them in place.

africart_floorboard_routing copy

This allowed all the floor boards to be inserted into place from one open end of the cart’s frame.

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africart_stage3_complete

Stage 4

Once the wheels and boards were fitted the whole cart was clamped so that the drawpins could be inserted and hammered into place. The whole of this exercise was done under considerable stress – some of the wood had twisted or warped. This led to one board havong to be twisted to get the tenon to pass through the mortice.

africart_twisted_plank

Putting the whole thing together under tension was brought together by the drawpining which closed any gaps in the wood joints.

africart_stage4_complete_bi

Stage 5

By this stage the cart was very nearly complete, however two things remained: firstly attaching the handle and second attaching a stand or prop.

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Here you can see the counter sunk nut securing the wheel spindle.

Originally I was going to connect the handle directly to the extended wheel spindle and that was it. However this proved too loose and kept pivoting and so needed some sort of support. I devised a plan of dowelling the 4″ wheel gap and pining an adjustable brace in position. By removing the pins, the cross piece can be withdrawn and rethreaded through the lower holes, thus enabling children, as well as adults, to comfortably use the cart.

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africart-001

There was now the problem of keeping the cart steady when at rest. Origonally I had thought of two poles that dropped vertically through the front of the cart’s load bed would surfice. However on creating the braces for the handles I saw an opportunity to use the same dowel pivoted system to produce legs.

Because the legs swing down to form an effective stand, they can be left as they will just swing away when they encounter any obstacle – then they can just be kicked out to make them ready again.

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Completed Cart

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Written by Mr. Elphick

February 16, 2009 at 12:58 pm

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