ReferenceFor more information about the control unit, refer to Systems Operation, UENR0357, "HH44 DE Harvester Head Dasa4 Control System".
A typical working cycle begins with the harvester head in the TILT UP position. The roller arms and the delimbing knives open. The saw is in the HOME position. The harvester head is positioned to the tree with the boom so that the trunk comes between the upper and lower knives and the feed rollers.
Position the harvester head on the tree. Grip the tree with the knives. Press the control button for the harvester head close inside the cab. When the control system receives the signal from the button, the two upper knives and the two lower knives will close. After a delay, the feed roller arms will close against the tree.
The harvester head now has a firm grip on the tree. The harvester head is ready for the actual felling of the tree.
Before you cut down the tree, plan the felling operation completely. Preplanning allows the tree to be felled in the desired direction.
Consider the direction of the wind, when you fell a tree. Consider the lean of the tree before you fell a tree.
The actual cutting of the tree from the stump is done by a hydraulic saw in the harvester head. Press the saw button in order to activate the saw. The saw motor will start to rotate and the saw bar will begin moving toward the tree. Keep the button depressed in order to continue the process.
The next step of the felling process will establish conditions for delimbing and for cross cutting the tree.
Fell the tree in a direction that is easy to feed through the delimbing/debarking knives.
Once the tree is felled, the processing begins. Processing the tree means that the tree is delimbed and/or debarked and the tree is cut to the desired lengths.
Delimbing is the removing of the branches from the tree. Delimbing is achieved via the feed rollers that pull the tree through the delimbing knives. Debarking is the removal of the bark from the tree. Debarking is achieved via the feed rollers that pull the tree through the debarking knives. The rollers cut/break the bark as the tree is fed and the knives shed the bark from the tree. As the tree is fed through the harvester head, the length of the log is measured by the feed rollers. This length is displayed in the cab.
The feed roller motors can be activated by pressing the Forward Feed button.
Feeding via the forward feed button will stop when the button is released.
Use the following method in order to feed to a preset length.
- Press the start button. The forward feed starts automatically. The feeding will continue until the preset length is reached.
- Preset feeding can be stopped by pressing the Override button.
- The control system controls the speed of the feed rollers. The tree stops within a set tolerance. The tolerance is set in the computer when the lengths are programmed.
- The knives will close around the tree when the length is within the setting tolerance.
- The saw will cut the log when the desired length is achieved. Cutting is done by pressing the saw button or can be achieved automatically depending on the computer selection for cross cutting.
- Place the cut logs in a pile after the tree is processed.
- Avoid cutting off branches or shedding the bark from the next trees on top of the pile of the processed logs. Cutting off branches makes extracting the logs harder.
When processing of the tree is finished, and only the top of the tree remains in the harvester head, reset the harvester head. Resetting prepares the harvester head for the next tree. Press the ALL OPEN button in order to open the delimbing knives, the bottom knives, and the feed rollers. The tree will drop out of the harvester head and the harvester head will tilt up.
Note: By programming the computer, a number of automatic functions can be activated. The log can be cut automatically and/or the feed can begin automatically after the cross cuts. These functions are examples that can be programmed into the computer. Study the Operation and Maintenance Manual for the harvester head as well as the Systems Operation for the control system, before you attempt to work with the harvester head.