The basics between potato harvester models are generally the same. The front part of your harvester (usually driven behind your tractor, but sometimes in front) pulls up the potatoes from the ground and feeds them into a conveyor belt of sorts. They then go through a 'cleaning' process.
This is where the potatoes are run over or put through sieves to remove dirt, clay and other vegetation. The exact cleaning process will vary depending on your type of potato harvester. Some use metal spokes to catch the debris, some push the potatoes through a chute that will clear the debris, and others run over polystyrene 'stars' that will also catch and remove debris.
One important factor for all potato farmers is to reduce the bruising throughout the harvesting process. Bruising is relatively self-explanatory, when potatoes make hard contact with any component of your harvester, they can bruise which will leave ugly marks.
Reducing and preventing bruising is one of the key factors driving potato harvester design. Whether it's reduced drops between compartments, or foam and rubber casings to catch falling potatoes, harvesters that are designed to reduce bruising are always a popular pick.
Something to keep an eye out for when buying a potato harvester is the rollback. When the product belt stops moving (whether on purpose or accident), potatoes not in the holding section will start to roll backwards and potentially fall back to the ground. Well-designed harvesters will feature a fail safe of some sorts--usually small bumps (often called pegs) or poles along the belt which will stop the potatoes from rolling further down.
Of course, there's more to a potato harvester than picking potatoes. You will also need to factor in road restrictions and regulations in your town or state. You may need to consider how you will transport the machine between properties if you own more than one, or are planning to share it with other farmers. This, plus the size of your crops, will be a big factor in the size of potato harvester you buy.
