TECH UPDATE: Small Log Mills
Compiled by Mel-Lynda Andersen
Copyright 1996. Contact publisher for permission to use.
McGehee Equipment Company manufactures a complete line of machines that processes lumber
from logs ranging from 3" diameter up to 9" diameter. One standard machine in
the line processes high volumes of pre-sorted logs. It has no scanning or positioning
capabilities; it runs pre-sort-ed logs end to end and can run up to 45 8' blocks per
The machine produces a split taper sawing solution in both the horizontal and vertical
planes. The second standard configuration is fully optimized and can make set changes
between logs. This version can full taper or half taper saw in both the horizontal and
vertical planes. It does real-time optimization of each log at piece rates up to 33 8'
blocks per minute, and has small canter heads at the primary breakdown. Online offset,
skew and slew of the log and centre cant make for the highest recovery possible, according
to the manufacturer. Maximum length of material to be run in this machine is 12'6";
maximum log diameter is 9". The machine operates at 500 fpm and is capable of
producing 33 9' pieces a minute.
Newnes Machine Ltd.'s TruEdge system focuses on small wood applications. The TruEdge
system arrives at the jobsite pre-wired and ready to install, reducing cost and down time,
according to the manufacturer. The process control is a basic, intuitive operator
interface. The mounting of the remote I/O on the equipment enables prewiring and
pretesting prior to shipping, which contributes to easy installation and startup, says the
company. The positioning table is still based on the charger concept; however, it is a
smaller version using a single through-chain feed. This concept provides feeding accuracy
and improved chain life, says Newnes, and facilitates feed speeds up to 1,000 feet per
The edger is a simplified shifting collar, splined arbor design with the option of two
or three saw versions with or without a reman head. The three-saw version uses a
simplified paddle tailer and the two-saw ver-sion uses a free span centre chain run. The
conventional transverse scanning system allows adequate processing time to carry out
sophisticated edge and trim decision making. Plan-View sensors, end column monitor and
reman operation are options.
The Sawquip curve-sawing system is a four-sided canter and a thin-kerf multi-saw edger.
The system works aided by gravity which turns a curved log on its side, after which the
canter infeed belt adjusts vertically for full or half-taper processing. The chipping
heads and saws follow the log contour, making it possible to process S-shaped
logs. Lumber recovery is said to increase with this system by 15 per cent; 26 to 32 8'
logs can be processed per minute, with a total of 10,000 logs processed per shift.
The system requires only one person to operate and features quick changing of knives,
saws and guides. The Sawquip chipping canter twin saw system features extended length
sharp chain infeed with auto-log rotator. With this system, the log is scanned and divided
into slices. The mass centre of each slice is calculated, memorized and the log form
determined. The best opening face is deter-mined in real time according to optimal
canter-twin saw cutting solutions.
Canadian Mill Systems
The Economizer Small Log Mill is a turn-key operation designed to cut rough logs of less
than 10" in diameter. The mill operates with four chipper heads t h at are operated
by state -of-the-art hydraulics. Set adjustments can be made quickly and are accurate to
within 1/16", allowing cants to be produced in metric or standard, from a minimum of
2"x2" to a maximum of 6"x6" with one pass t h rough the mill.
By adding one or a combination of up to three horizontal saws to the outfeed side of
the mill, the processed cants can also be split into lumber of any dimension, all on a
single pass through the mill, says the company. Production is approximately 1,400 to 1,800
board feet per hour, which represents an average payback period of less than one year.
The MaxiView system is designed to simulate all sawing functions within a sawmill. This
system accepts all relevant data for lumber sizes, saw kerfs, wane allowance, material
flow and lumber value. It also offers full sawmill simulation, from the headrig to the
trimmer, according to the manufacturer.
Real-time value optimization determines the highest value sawing for each log, and the
reporting capability has optimized 32-bit programming. Log data can be entered into the
Maxiview in three ways: by keyboard or mouse; loading from a data file; or allowing the
computer to randomly create a log mix.
This system can be installed on your existing desktop PC running Windows 95. It
produces a colour-coded view of the end, top and side of each log showing primary saw
lines, as well as a colour-coded view of each slab and saw line, showing edging and tri m
l ines, and result ing lumber. Simulation data can be saved to a disk for later recall.
TS sharp chains are utilized in a variety of small log mills. The manufacturer has
sys-tems running in hardwood from 4' to 8' and softwood from 8' to 16'. These systems are
also running with circular twins and bands. The sharp chain runs on a Redco Wear Surface.
A series of hold-downs ensure that the cant stays on the chain. TS Manufacturing can also
modify your existing sawing system to accept the TS Sharp Chain System.
Optimil Machinery s small log break-down system featuring double-length or extended
length infeeds are designed to rotate and hold the log in position for optimum recovery.
Log position is determined by Optimils auto rotation scanner.To hold the log in
place, Optimil uses two pairs of spiked rolls, which are controlled by linear position
with air cushions. A benefit of their system is the flare reducer heads which help remove
the fla re butts before the scanner. These infeed systems are used to feed logs into
Optimil two-sided canters with sharp chains or four-sided canters for further log
USNR has introduced its new high-speed edger infeed that can process 35+ boards per
minute. According to the manufacturer, this enables one edger to do the work of two. The
new design of the Schurman Model 650 Edger Maximizer Infeed closes the gaps between boards
while maintaining maximum recovery, says the company. This tested infeed system processes
random length materials at speeds of 35+ ppm. On stud length material the count is said to
be even higher
The DDM4 and the High Recovery Small Log Line are manufactured by Denis Comact to process
small logs. The DDM4 is a one-pass machine with a four-head canter and a close-coupled
vertical arbor edger. Logs are scanned by a Multimeg Optimization system and positioned by
an automatic flying log turner. Main features of the DDM4 include the Sweep Orientation
System; 450 FPM feedspeed; perfect centering of log in the machine; curve sawing;
heavy-duty con-struction and design for North American mills; canter heads with bent
knife; guid-ed saws; and PLC controls and servo -positioning.
The High Recovery Small Log Line has a full-profile Multimeg scanning system,
Opto-Rotation Flying Log Turner, double-length infeed; bent-knife canter, CETEC twin
bandsaw, linear full-profile scanning and cant positioning, and controlled curve-sawing
edger. This high-tech small log line will produce 265 board feet per m 3 of logs from
3-1/2" diameter to 10" diameter at 450 FPM (or 30 logs per minute).