What hand is it anyway? There is some confusion in the industry regarding the "hand" of certain machines. The following is my opinion based upon 38 years of experience in the sawmill and wood products and wood processing machinery businesses. I hope you find it helpful.

Most experienced sawmill folks know the difference between a right hand sawmill and a left hand sawmill. Beyond the headrig however, the hand of certain sawmill machines becomes a little more confusing. Partly to blame for this is the "method" by which some use to determine the hand of a sawmill. Over the years, I have listened to many sawmillers and machinery sales people say that if the wood passes from the operator's right to his left, the machine is a right hand. This is justified by observing that from viewpoint of a sawyer with a cab in the most common position and sawing on a right hand sawmill, the log is passing from his right to his left as it enters the saw. This is true regardless of whether the headrig is a circle saw or a vertical band. But this applies only as long as the operator's cab is located in the conventional location. I visited a new mill in upstate New York which had the operator located at the end of the track. In that case, a left hand mill, the log entered the carriage on his right and moved away from him as it entered the saw.

Similar reasoning applies for rosserhead debarkers. Typically on a right hand sawmill, the rosserhead debarker operator cab is on the left side of the debarker and left side of the log deck as seen when loading logs on the deck. The logs pass by him from right to left and becaue it is standard for a right hand sawmill, it is referred to as a right hand debarker.

Unfortunately, this method doesn't work for band resaws, trimmers, sorters, stackers and chippers. First let's look at vertical band resaws such as the popular linebar resaws. This is where the question of hand arises most often and where there is a lot of confusion. There are actually 4 different configurations for linebar resaws because the resaw itself can be left or right hand, and the linebar attachment can be on either side, left or right. All four combinations are possible. To add to that, the operator can be located to the left, to the right, or even above the infeed to the saw. So, using the method of determining the hand by how the wood passes the operator, fails to consistently determine the hand. Now, digging further, let's set aside the location of the linebar attachment and focus on the resaw itself.

Perhaps you have heard that a right hand band headrig, if removed and re-installed as a resaw, would become a left hand resaw. This is true. The opposite is also true. A left hand headrig would convert to become a right hand resaw. Headrig blades are hung on the wheel from the front side of the machine where the wood enters while resaw blades are hung on the wheel from the backside where the wood exits. But even with all of this confusing information, one thing holds true regarding the hand. Facing any band headrig or band resaw from the cutting side of the wheel, if the wheel is turning clockwise, it is a right hand configuration and uses a right hand blade. Similarly if turning counterclockwise, it is running a left hand blade. The same also applies to horizontal resaws. If facing the machine broadside as the wood enters, if the wheels are turning clockwise it is running a right hand blade. This holds true on horizontal resaws whether the wheels are above the sawline, or below the sawline. So from this we learn the best way to determine the hand is by wheel rotation.

This logic can also be applied to chippers. Facing the cutting side of a chipper disk, if it is rotating clockwise, it is right hand.

But, what about the hand of trimmers, sorters, and stackers in the sawmill? In the case of trimmers, there is no consensus of hand. Some folks claim for example that a trimmer which has the operator on the left side (zero lumber length end) is a right hand because the wood passes in front of the operator from his right to his left. Others (like me) determine the hand of the trimmer by noting the location of the “zero” end of the lumber. This is often called the zero line or the lumber line. It is the even end of the lumber, regardless of the length. So, I would call the example trimmer a left hand.

There is little to no argument that a lumber stacker and a lumber sorter with the zero end on the left, is a left hand machine. Why then, when you have a trimmer in line with a left hand sorter and a left hand stacker, would you refer to the trimmer as a right hand? The fact is, if you use any logic, you wouldn't. Therefore trimmers, sorters, and stackers are properly identified (in my opinion anyway) by which side the zero end of the lumber is, while looking downstream...in direction of flow...not by how the lumber passes in front of the operator.

So, to summarize, there are various methods depending upon the type of machine.

Conventional Circle Sawmills & Rosserhead Debarkers - if the log passes the operator from right to left, it is a right hand machine.

Bandsaw Headrigs & Resaws: Facing the infeed, if the wheels are turning clockwise, it runs a right hand band.

Trimmers: There is not a consensus on trimmers but most in the industry determine the hand based upon the “zero” or even end of the lumber while facing the infeed. If the zero end is on the left, it would be left hand.

Sorters: Location of the "zero" end of the lumber looking downstream determines hand.

Stackers: Same as sorter....location of the "zero" end of the lumber looking downstream.