Guide to Portable Swing Blade Sawmills
Swing blade sawmill technology was introduced in 1988 in New Zealand by inventor Carl Peterson. There are now several swing blade mill manufacturers all over the world. The technology of these mills is gaining in popularity and the industry is growing.
Swing Blade technology works similar to band sawmills in that a movable head travels along a track to cut a stationary log. It uses a circular blade that swings from a vertical position to a horizontal position. This feature allows the sawyer to cut while moving the head in both directions, thus increasing production over a similar size band sawmill.
Production on swing blade sawmills seems to outpace similar sized band sawmills most of the time. This is in part due to the fact that you can cut in both directions with a swing blade mill. Another factor is that the log does not need to be rolled once the cutting starts. This is important for momentum—if you have to stop sawing to turn the log, you lose momentum.
The amount of yield per log is also increased with a swing blade sawmill. You can cut a log with precision, it is like dismantling the log instead of slicing it. By edging the boards as you cut them you can maximize your output. This is something that you have to see for yourself to understand fully. It is recommended that you watch one of the many swing blade sawmill videos on the web showing one of these machines at work.
It is tougher to cut small logs on some swing blade sawmills. Big logs are where they really earn their keep. You can cut the log where it lays by setting up the machine over the log. This eliminates the need to roll the log onto the bed of the mill.
One caveat is that you are more limited in the size of lumber you can cut with one of these mills. Maximum lumber sizes range from 4” x 8” to 24” x 24” depending on the make and model you choose. Many manufacturers offer a slabbing attachment which consists of a bar and chain like a chainsaw to cut wide slabs. The downside to this is speed—the barn and chain cut slower because it has a thicker blade. This makes more resistance and takes more energy to make the cut.
Saw Blades and Kerf
The saw kerf on a swing blade mill is thicker than on a band sawmill. There is a trade-off with this, in that more sawdust is produced but the kerf is thinner than on stationary circular sawmills. You must determine if you are more concerned with accuracy or saw kerf.
The circular blade on a swing blade mill has carbide teeth, so it will stay sharp longer and can be sharpened without removing the blade from the mill. Replacement blades are rather expensive, but they will last a very long time. It is best at cutting timber that is clean. If you cut a lot of logs that could contain metal, it would be best to go with a band sawmill instead.
Price and Resale Value
Swing blade mill prices can range from $6,000 to $40,000 depending on the model and options you choose and they retain their value very well. You can expect to sell a well maintained used mill for anywhere between 70% and 90% of its original price.
Most makes and models of swing blade mills can be transported in an 8' bed of a pickup. They break down so they can be carried to the log even if there is no vehicle access to the log. This is great if you have to cut the log where the tree was cut, such as in a backyard or out in the wilderness. The saw head can be heavy to carry, so portability is limited to how far you can carry the saw head.