Whether you plan on building your horse cart from scratch or a kit, you will need to follow a set of plans. Horse carts come in all sizes and many shapes as well. Plans are simple to buy and execute if you follow a few guidelines to get the right size cart and make sure it is safe for you and your horse.
When you purchase your horse cart kit, the only measurement you need is the length of your horse from chest to tail. This is the measurement that determines the length of the shaft, or swingletree. To design a building plan of your own, you will need to understand how the dimensions of your cart fit to the size and measurements of your horse, so that it is appropriately proportioned.
There are some parts of a buggy or wagon that can easily be made by hand. The seat is basically a slab of plywood for the bottom and back joined on a seat frame and padded if desired. The bed of a wagon is a big box on axles. However, some parts should be purchased unless the builder has a great deal of experience and all of the tools needed for shaping wood or metal. The shafts of a cart or swingletree of a wagon need to be the correct size and shaped to fit your horse's body. Axles are similar to the axles on any vehicle and require precision. The "fifth wheel" (the piece that attaches multiple hitches of horse pairs to the wagon) is iron and must be welded precisely. If you buy a kit, all of these parts will be included and shown on the plans.
Balance is very important when constructing a two-wheeled cart. It isn't an issue for wagons. A four-wheeled wagon does not tilt the way a two-wheeler does, putting more pressure on the horse's shoulders and back. Even a cart built from a kit or purchased fully-assembled must be balanced before hitching your horse to it for the safety of your horse.
How To balance a cart
Stand between the shafts of your two-wheeled cart. This is where your horse will be. Allow the tips of the shaft to rest in the palms of your hands. Have a friend sit in the cart and see how the weight shifts. There may be a momentary weight in the palms of your hands, but once the rider is seated that weight should be lifted and the shafts should lay gently in your palms. If there is a heavy weight on your hands, adjust the seat backwards until the rider can get in and sit without putting pressure on the shafts. If the shafts lift out of your palms, adjust the seat forward until the rider can get in and sit with the proper amount of pressure in the shaft.
Horse cart plans should be followed to the letter to obtain maximum safety for both horse and driver.
Before hooking your horse to a cart of any type, train her properly. You or the person driving must also be trained.