All kinds of wood species are being cut daily with SERRA sawmills
- Mangelsen in Sweden cuts curved oak, being used for building
- Kantor in Hungary cuts Siberian larch for manufacturing
doors and windows;
- McMinn in Washington State mills wood for musical instruments;
- Timmerman in Barrie, Ontario, mills posts and beams for timber
Cutting lengths are between 0.7 and 16 meters (2 to 52 ft) (mills
set up to be stationary can be longer). Log diameters are between
0.10 up to 1.30 meters (4" to 4 feet). It doesn't matter
what you cut: building wood, veneers or fine wood, the cutting
thickness is quickly and easily adjusted and the SERRA saw lets
you produce at highest output. With our hydraulics you can easily
do all kinds of cuts, even if you have to produce octagonal (8-sided)
beams. Depending on the equipment, log diameter, dimension of
cuts and number of helpers you can cut up to 3m³ per hour.
Some SERRA customers have consistently been working the last
few years in three 8-hour shifts with a productivity of 15,000
m³ per year.
based on years of experience:
An angled sawhead with variable blade length settings. Results
in increased productivity and output of the mill.
The Bavaria SL series of SERRA sawmills
allows the operator to adjust the cutting width of the mill according
to the log diameter. The hydraulic blade tension allows you to
use different blade lengths - long blades for big logs and short
blades for small logs.
The blade guard around the right bandwheel moves together with
the wheel while tensioning the blade. This gives you enough room
to cut logs as big as 1.60 m diameter (Africa).
By using a short blade you cut logs of a diameter up to 1 meter.
Since most of the logs you may cut are smaller than 1 m, you
can cut most of the time with short blades. Because the wheels
are closer to the log you are able to cut at a faster rate,
achieving higher output.
The following sequence of steps shows one way to fill the customer's
order with optimal efficiency:
the positioning and securing of the log, the top cut is made.
With the initial cut there is a slab of bark, and with each following
cut there is a side with bark which will have to be trimmed later.
the log is turned 90° and secured again. Again, there is
the bark and the sides to trim. Of course, the log can also
be turned 180°.
process is repeated after renewed turning. The entire side
bark can be trimmed with the sawmill or later with our mobile
edge trimmer "Duett".
remaining wood can now be sawn as edged lumber or to customer
Log clamp turner
A SERRA Innovation: Patented in 1992.
this system you can clamp and turn the logs in the fastest possible
way. It works well for special cuts or conical logs. Beams as
well as stacks of boards can be turned, making it easy to do
double cuts, quarter sawing or use a flexible cutting schema.
The optional SERRA computer automatically optimizes the cutting
speed through the wood, positions itself at the right height
for the next cut and is able to cut a whole log by itself. Its
5.7 inch display makes it easy to read even under sunny conditions.
The positioning program
- Absolute value:
You input a value to which the saw will position itself on
start. You can set this value while milling a previous
process and it will only be executed when the mill is at
the start position and actually activated.
- Single board program:
The operator inputs the value of the next board thickness.
For example, the actual sawblade height position is at 330
mm. The desired board thickness is 35 mm. The computer adds
the kerf of 2.2 mm (this value can be adjusted depending
on the saw blade) and positions itself at 295,8 mm. After
the board is sawn, the computer will lower the sawhead for
the next cut by 37.2 mm. The tolerance can also be set; the
positioning is much faster at a tolerance of 0.2 mm than
with a tolerance of 0.1 mm.
- Programmed cuts
In this program the computer calculates how many boards can
be cut at desired thickness from the actual height of the
log. An estimated amount of remaining wood is indicated.
It is also possible to restrict the number of boards of one
size and ad other sizes to the cut order.
For example: The log is cut once and then positioned on that
side at a height of 400 mm. You want to cut 2 x 30 mm, 3 x
80 mm and finally 2 x 30 mm again. We set the kerf at 2.2 mm.
The total to be cut is 372 mm including kerf. The display will
indicate a remaining height of 28 mm. At start the computer
will position itself at 372 mm for the programmed cuts.
- Memory function for driving back the sawhead
The operator positions the sawhead a few centimeters above
the log and presses the memory button for three seconds.
The operator starts sawing and after doing the first cut
and the sawblade exits the wood, the operator presses the
memory button, the sawhead will drive up to the first position
and the sawhead is able to drive back to the operator. If
the cut board is taken off by a helper, the operator presses
the "X" button rather than the memory button and
the sawblade will position itself 1 cm above the last cut
(this value can be set as needed).
The wood calculator
The size of the log (length and diameter) is entered in order
to calculate the volume of wood being sawn. The program allocates
an order number to each log. In this way you can set a different
price for each log according to the type of cut you do (e.g.:
simple cut, double cut, hardwood, special cuts, etc.). The order
number represents the order from the customer and is given in
Excel format. The amount of wood sawn is saved on a CF card which
can be transfered to other computers for invoicing.
Fully automatic operation
Automatic operation of the SERRA sawmil can be useful for many
sawmill operators. Mainly you would use it for doing repeated
fine cuts of the same thickness. In this way a sawyer can operate
two machines at the same time. Once the log is prepared and fixed,
the program can start and the machine will do all the cuts by
itself. Because of the new AVS system (more below) the machine
will know exactly what speed it has to cut and it will regulate
cutting speed by itself.
Off-position cut protection and joystick
With the joystick you can do all the mill operations with one
hand: raising / lowering of blade, forward / backward motion,
sawdust container shute opening, pre-cutter setup, throttle and
the start for the next cut. (See this in action in the videos.)
As the joystick is connected to the computer and positioning
system it is possible to prevent the sawhead from cutting into
the squaring arms. The controller recognizes where the height
of the squaring arms is and stops the forward motion.
(CSCA) - Cutting Speed Controlled
The new CSCA system developed by SERRA controls the amps consumed
by the main engine and maintains it at a constant. This controller
can be used in combination with the joystick. Every 400 miliseconds
the computer checks the amperage, and if it has increased, the
computer regulates it automatically via an electromagnetic valve.
There is no way for a human being to react as quickly. As the
blade enters the log the operator sets the joystick to its maximum
speed and the computer takes care of the rest.