Sparkey Carts

This is essentially my first cart, pictured on a farm in Wales soon after I started playing pony. It was built with standard 22mm copper tubing and plumbing fittings. It is the strengthened version of the one that tipped Sir Guy out backwards. Even so, if you look carefully you can see the broom handle splint held on with black tape holding the shaft together, having broken during the day. By the end of the weekend the 27x1.25" bicycle wheels had both buckled and the chassis was bent slightly. That is when I discovered that there are 'real world' stresses imposed on the whole system.

This formed the basis of my light cart that I still use today. I have also kept a similar shape to to the shafts that leave the bum clear, and the seat still has spring suspension - I have a new seat that will, I hope, enable me to remove this potentially weak spot. Another feature that has always been present is that the carts come to pieces to fit in the back of a car.

Here I am waiting patiently for some attention at Whiplash '98. The core of the original chassis is there, but it has been extensively modified. An important change is the shafts, now more like the usual set-up. The original design allowed the part attached to me to rotate through 360 degrees - unfortunately it tried to do just that at an event in Shropshire and tipped my Lady driver out! The cart is now much more stable. I also fitted a solid axle, drilled and tapped at the ends to take standard wheelchair wheels, which made the whole assembly stronger and lower.

The pictures on the right are of my second cart, the first taken at Whiplash '98, and the second at Petweek 2000. The only changes in that time are the second footboard to satisfy several drivers using the shafts for their feet, and a better plywood body with mudguards. Though a bit heavier than the first, when the driver is aboard to balance it I do not really notice it.

I borrowed the tail from Kai, the German guy that organises Petweek.

An important discovery that Sir Guy told me about is that 20mm steel electrical conduit is a perfect fit inside 22mm copper plumbing tubing. This gives the strength of the steel and the ease of assembly of the copper. Since adopting this method both carts have stood up to quite a bit of punishment with no failures.


	These pictures show the current form of my first cart, taken at the De Ferre farm. Two major changes to it - the wheels and the shafts. The wheels are 600mm steel rims mounting on a 19mm axle, first used by the Ladies of De Ferre, but soon adopted by myself and Sir Guy. I changed the shafts because the original design was peculiar to my harness. The only way for other ponies to be harnessed to them was either a bodge job, or to use the belt that I made fittings for that Sir Guy took to events. This design looks tidy, I think, and uses what is becoming a common three-point fixing - it also still keeps the bum clear. The third picture shows the latest mod to the cart, and it was so new that I had not painted it then. It is a towing hook, used for pulling a rake and barrow around De Ferre.

This is my latest version of the shaft arrangement already seen above, that I am reliably informed by Gord is a whiffle-tree. The photo clearly shows how it adjusts for different height ponies. I have made one addition to the actual shafts - there is now a rod connecting the two shafts at top back centre to form a parallelogram to stop them flexing from side to side too much.

So, what have I learned over the years of developing my carts?

Do not underestimate the stresses that are imposed on the whole system. On the flat these would not be small, but over bumpy ground and uphill they gets much greater.
Using copper tube and steel conduit enables a light and strong cart to be made using basic hand tools and a gas torch. The conduit passes through the reduced diameter of the copper 'T' joints, making a joint along a length that much stronger. Another advantage is that the cart can be assembled without soldering, so it can be fiddled with to get the design right - and as you have seen, it can be carefully unsoldered to make modifications later.
If you use copper tube as I have, make sure the gas torch is a fairly big one. The joints take a lot of the stress, and you will not make a good one if it does not get really hot.
Unless you are planning to use the carts only on flat level ground, stout wheels are essential. Even the mountain bike wheels were slightly buckled by the time I stopped using them!
Keep the centre of gravity reasonably low. I have seen a couple of potentially nasty accidents where a cart turned over, taking the pony with it because they were harnessed in with no use of their arms.
Look at other peoples carts - I am always searching for pictures. You can get an idea for what works and what may not, or just see a design that you like and try to copy it. Part of the reason for putting this site together is to give something back to the pony community for a change.
Look for 'standards' in existing designs, which in my case was mainly where the pony is attached to the shafts. This will enable other ponies to use your cart, and mean that your harness is compatible with other carts.
The position of the driver over the wheels is very important for the comfort and safety of the pony - there should be a slight bias towards putting weight on the front. If possible, make your seat position front to back adjustable. If you intend to use it for one pony only, the correct balance can be built in, but if it will be available for others to use, some ponies may find it hard going. This was evident when a shorter pony than myself was harnessed to my second cart, which has quite a bit of forward weight to start with. Because the cart tipped down at the front, the driver's weight was forward of the axle, thus making the problem worse. By moving the seat back an inch or so, the weight of the driver was back just behind the axle, and the correct balance was achieved. As you can probably imagine, this balance is particularly important when a male driver has a ponygirl in front. If he is too far back there will be a tendency to lift the pony into the air.

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