Important Warning: This is a historical archive text, not a current standard, machine specification or operating manual. Formulas, slopes, dimensions, humidity and overhangs must be checked according to valid standards, machine manufacturer’s documentation and specific production process.
This text is not part of the current offer of Savo Kusić, which is focused on windows, doors and associated solutions.
Log movement and saw tilt
Mechanisms for moving logs can be continuous or intermittent. With continuous movement, the log moves continuously and evenly during the working and idle stroke of the gater frame. With intermittent movement, the log moves only for one part of each rotation of the shaft - intermittently. Intermittent movement can be performed during working or idle running of the gater.
Continuous movement is used in fast-moving double-decker gatekeepers with a high number of revolutions; intermittent movement - in slow-moving gaiters with a low number of revolutions.
To cut logs on the gutter, it is necessary that the saws in the gutter have a certain slope. The magnitude of the linear slope is determined by the continuous motion pattern:
y: Δ / 2 + (1/2) mm; for intermittent movement during the working stroke y= 2 to 5 mm; for intermittent movement during idling y = Δ + (1/2) mm.
Here, y is the nagi of the saw in the frame, mm; Δ - movement of a log or beam during one rotation of the gater roller, mm.
Picture 1: Inclinometer for measuring the amount of inclination of the saw
The overhang (inclination) of the saw is checked with an overhang gauge. The overhang gauge consists of two steel strips that are connected to the joint at the top, and at the lower end with a transverse strip with an expression for the passage of the tensioning screw with a butterfly nut. A spirit level is fixed on one steel strip. The slope is read in mm on the length of the frame stroke on the scale, which is located at the bottom of the accessory (fig. 1).
In order to cut boards or beams of the required thickness between the saws in the frame, inserts (dividers) are inserted, the width of which exactly corresponds to the thickness of the beam to be cut.
Spanung and dividers
Spanung is a set of saws in a frame with set distances between them, on the basis of which the sawn timber of the required dimensions is obtained. The thickness of the insert is determined according to the formula S = a + b + 2c mm. Where S is the thickness of the insert; a - nominal board thickness; b - excess for drying; c - the size of the spread of the teeth on one side.
Inserts (fig. 2) are made from dry wood (with a maximum of 15% humidity) birch, chub, beech, ash.
Image 2: Inserts (dividers)
Allowance for drying is added to the dimensions of width and length of sawn timber - pine, spruce, fir, cedar and larch, which is obtained during mixed cutting (with tangential-radial arrangement of annual rings) of wet logs or when cutting wet sawn timber to ensure obtaining the required dimensions of the timber in the dry state.
Excesses for drying conifers
The sawn timber of the enumerated conifers is divided into two groups according to the size of the drying excess: the first includes pine, spruce, cedar and fir, the second includes larch.
The thickness and width measurements of sawn timber with initial moisture over 30% and final moisture 15% are given in table 1.
10-13
16
19
22
25
30
35
40
45
50
55
60
65
70
75
80
85
90
100
110
120
130
140
150
160
170
180
190
200
210
220
240
260
280
300
0,6
0,8
1,0
1,0
1,0
1,5
1,5
1,5
2,0
2,0
2,0
2,5
2,5
2,5
3,0
3,0
3,0
3,5
3,5
4,0
4,0
5,0
5,0
5,0
5,0
6,0
6,0
6,0
7,0
7,0
7,0
8,0
8,0
9,0
9,0
0,8
1,0
1,5
1,5
1,5
2,0
2,0
2,0
2,5
2,5
2,5
3,5
3,5
3,5
4,0
4,0
4,0
4,5
4,5
5,0
5,0
6,0
6,0
6,0
6,0
8,0
8,0
8,0
9,0
9,0
9,0
10,0
10,0
12,0
12,0
When cutting logs or beams with a moisture content below 30%, the size of the excess is calculated as the difference between the size of the excess for the required final moisture and the excess for the existing moisture of the wood. Sawn wood of hardwood species, which include beech, hornbeam, birch, oak, elm, maple, ash, aspen, and poplar, are divided according to the amount of drying into two groups for the tangential direction and into two groups for the radial direction.
Excesses for drying hardwoods
The first group includes birch, oak, maple, ash, alder, aspen and poplar, and the second - beech, hornbeam, elm and linden.
For half-radial sawn timber (with tangential-radial grain direction), the allowances determined for wood with tangential grain direction should be given. Overmeasures for thickness and width for sawn timber in tangential and radial direction with initial humidity of 35% abs. and more and final humidity 10 and 15% abs., and depending on the group, they are determined according to table 2.
Table 2: Overmeasures for sawn lumber of hardwood species, mm
