became popular in the United States starting in the 1970s, when the 1973 energy crisis and the back to the land movement had led to renewed interest in small woodlot
A woodlot is a term used in North America to refer to a segment of a woodland or forest capable of small-scale production of forest products such as wood fuel, sap for maple syrup, sawlogs, as well as recreational uses like bird watching, bushwalking, and wildflower appreciation...
s and in self-sufficiency
Self-sufficiency refers to the state of not requiring any outside aid, support, or interaction, for survival; it is therefore a type of personal or collective autonomy...
The first portable sawmills were the "One Man Farmer's Sawmills." These mills featured large circular blades and were marketed during the early twentieth century by companies like Sears, Montgomery Ward and JC Penney. These machines were all "private label" machines manufactured by the Belsaw Company. Many early sawmills were designed to be belt-driven from a steam traction engine (which could also be used to transport the saw) Belsaw also sold sawmills under their own name until the early 1990s. After this the Belsaw line of equipment was sold under the name "TimberKing."
Prior to the advent of the portable 'mill, small-scale sawmills were generally cobbled-together affairs constructed and operated by (almost always) two men with a penchant for tinkering. This was, and remains, a traditional occupation for Amish
The Amish , sometimes referred to as Amish Mennonites, are a group of Christian church fellowships that form a subgroup of the Mennonite churches...
men; unlike most mechanical systems, small sawmills typically do not use electricity.
More recently, portable bandsaw mills represented a dramatic shift in design. Unlike traditional mills, they used a resaw blade of the type used on a band saw
A bandsaw is a power tool which uses a blade consisting of a continuous band of metal with teeth along one edge to cut various workpieces. The band usually rides on two wheels rotating in the same plane, although some small bandsaws have three wheels. Bandsawing produces uniform cutting action as a...
rather than a circular blade, which reduced weight and cost, and reduced the size and weight of the bearings and support blocks. The smaller kerf on these blades dramatically increased the yield from a given log. Use of band blades also allowed for a different design where the head
, consisting of the blade and a power source, moves back and forth while the log remains stationary. This is in contrast to traditional mills where the log moves on a trolley while the blade remains fixed.
Larger mills have recently come on the market which are portable only in sections. These cut faster and can handle larger logs but do require additional set up.
Portable mills can be trailered and set up on site, next to the trees being cut. There is a good degree of shimming and alignment needed to set the rails straight, and this takes time. Some businesses transport their mill to harvest urban timber where moving the logs would be impractical.
The portable mills can cut lumber with speed and accuracy, though the subsequent steps of planing
must still be performed to produce finished lumber
Lumber or timber is wood in any of its stages from felling through readiness for use as structural material for construction, or wood pulp for paper production....
. Commodity lumber in standard sizes can be made this way. Occasionally, this is done.
The more common use, however, is in the production of specialty timber products not readily available through lumber yards. Portable mills are particularly effective for truing up logs for use in log construction, replacing the traditional use of a drawknife, which is inordinately time-consuming. They are also used for low-volume production of specialty hardwoods used in furniture, and can be used to produce the large timbers used in post-and-beam framing techniques.
Portable mills have also been used in conjunction with salvage logging operations. In salvage logging, logs that were lost underwater during nineteenth-century river-borne log drives are recovered by divers. These logs are often worth many thousands of dollars. The thin kerf blade of the portable sawmill allows for much higher board foot yields from these valuable logs.
A Timberjig is a light-weight device that is fitted to a chainsaw and makes it possible to cut straight squared boards and planks from a log. The first cut is made with an aluminium or home-made wooden guide rail that is attached to the log ends. The following cuts are guided by the previously sawn...
allow a chainsaw
A chainsaw is a portable mechanical saw, powered by electricity, compressed air, hydraulic power, or most commonly a two-stroke engine...
equipped with a ripping
In woodworking, a rip cut is a cut made parallel to the wood grain. Rip cuts are commonly made with a table saw, but other types of saws can also be used, including hand rip saws, radial arm saws and band saws...
chain to be used like a sawmill.