Purpose

The forage harvester is one of the few farm machines that can be used equally well for several purposes.

The primary purpose is to chop field crops and place them in a wagon or truck. Both cutter bar attachments and row-crop attachments are provided; so both field-crop and row-crop forage can be cut, chopped, and blown into the wagon in one operation.

A pickup device may be used to pick up crops already mowed and raked into windrows. This method permits the forage to wilt before it is chopped, and some people consider wilting necessary. When silage is picked up from the windrow you can get a load with less travel than with the direct-cut method.

Another use for the pickup attachment is to chop hay and straw. Chopped hay and straw are much easier to handle than long material.

Some farmers have used their forage harvesters to chop and load their grain crop, which is then run through a threshing machine to finish separating the grain.

The row-crop attachment harvests one or two rows, cutting the crop into pieces and depositing it in a wagon or truck. You can harvest very tall corn and even down corn with this attachment.

types

The tractor-drawn harvester is supported by two rubber-tired wheels and a tongue that is attached to the tractor drawbar. There are two main types of trailing harvesters – PTO-operated and engine-operated.

The tractor-mounted harvester may be fully mounted or semi-mounted. Fully mounted models are carried and supported entirely by the tractor.

The self-propelled harvester is one complete unit, for large-farm operators or for custom operators.

The pickup and cutting units of all these machines are quite similar and will be studied together.

Versatility. The number of attachments available varies with the different manufacturers. Of 18 manufacturers of forage harvesters, 17 make pickup units, 18 make cutter bar units, and 13 make row-crop units. So you can get a unit that will do several jobs on your farm or one suitable for custom work.

Method of Cutting. Two main types of cutters are used. About half the models have cylinder cutters and half have flywheel cutters. The cutting cylinder usually has knives like a lawn mower reel. But one manufacturer (Lundell) makes a revolving cylinder (or drum) with attached hammers or knives, usually called flails. This is an adaptation of a stalk cutter to forage harvesting.

Specifications

Specifications tell what your machine can do. Of course you want to choose a machine that will handle your crops in an efficient manner. Farmers often purchase a machine too small for their work. They get impatient when, because of overload, it clogs or breaks. On the other hand, a very large machine may be too expensive for you unless you do custom work. Then you need a large-capacity machine.

There is no very satisfactory way of rating the capacity of forage harvesters. A machine will always handle more wet forage than dry. The amount depends largely on the percentage of moisture in the crop, the yield, evenness of the stand, speed of the apron, length of cut, windrow size, cutter width, and whether the crop is tall, heavy, or down.

A PTO machine should have as much capacity as an engine operated machine, if the tractor has sufficient power. If your tractor is small, you should buy a harvester with an engine on it. Otherwise, you may not be able to use the machine up to its capacity. Engine-operated harvesters cost more. The engine weighs 600 to 900 pounds and may add as much as a thousand dollars to the cost. And you may have no other use for the engine during the rest of the year. However, an engine is desirable for doing custom work and when the crop is very heavy. The tractor can be slowed by the throttle while the harvester engine handles large windrows.

A PTO model is not as conveniently hitched to the tractor because the PTO shaft must be hooked up also. And, with the universal shaft, you must be careful not to turn too short; universal joints are often broken by operating at a sharp angle under load.

Sometimes knives must be sharpened twice or more per day. They should be easily removable for sharpening, or a sharpening attachment should be available so they can be sharpened without being removed. Knives must be adjusted very accurately; therefore they should be easy to get at.

When doing custom work you may want to change cutting lengths quickly – in 10 minutes or less. One machine has a truck gear shift that changes cutting lengths in seconds. Another has a step-pulley system on which you slip the belt from one size pulley to another. Most machines use gears to change the conveyor apron speed and cutting length. This takes more time.

Hay should be cut rather long – perhaps 4 inches. Grass and legumes for silage may be cut the shortest, perhaps 14 inches. Corn stalks and ears are quite satisfactory cut at 1/2 inch.

A movable discharge spout is handy. You may want to load into a wagon and later into a truck. This may mean changing the spout from rear delivery to side delivery. Removing and replacing bolts each time the spout is changed are not convenient.