 |  | Operations on Band and Circular Sawing Machines - Course: Mechanical woodworking techniques. Trainees' handbook of lessons (Institut für Berufliche Entwicklung, 19 p.) | ||
 |  | 10. Band Sawing Technology | ||
|  | 10.1. Oblong and Cross-cuts | ||
| | 10.2. Curved Cuts | ||
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Setting up the machine:
A band saw blade is positioned in the desired width according to the material being processed. The guard devices and roll sheathing are opened and the saw blade is chucked. The band sequence is so regulated by setting the batter of the top band roll so that the saw blade teeth are positioned in front of the bandage.
Thereby the band rolls are manipulated manually. The guide rolls above and below the table should be so set that the teeth are positioned in front of the rolls and the blade glides easily between the rolls. There remains and air fissure of one mm between the rear and band rolls. The guard devices and roll sheathing must be ground prior to undertaking a trial run.
Marking the workpiece:
The workpiece is pencil-marked according to the size data of the technical drawing. Given simple, straight cuts the width can be set directly on the stop rule on the machine table.
Saw cutting:
Switch on the machine and ensure smooth saw blade running. Position the workpiece securely in from of the saw band. Use both hands to guide the workpiece and push it slowly through the saw band. An untrue cut may arise through the following shortcomings:
- a too narrow saw blade
- irregular teeth setting
- insufficient saw blade chucking
- a too blunt saw blade
- idle running in the soft annual rings through too great rate of speed
Controlling size consistency:
The sizes are determined by commensurate measuring means.
Which band saw blade is chucked for straight oblong and
cross-cuts?
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Why must the workpiece not be pushed through at a high rate of
speed?
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Setting up the machine:
Select the saw band according to the type of material and curve radii:
- narrow saw band for small radii
- wide saw band for wide radii
Commensurately, as already described, set up the machine accordingly.
Marking the workpiece:
Mark the kerf outline on the workpiece surface employing suitable marking means or aids.
Figure 22 Marking curved cuts
with templet 1 pencil, 2 templet, 3 plant, 4 reference edge
Saw cutting:
Hold and guide the workpiece with both hands. It is cut freely at the marked points.
Always keep hands away from the sawing area!
Select a slow speed rate!
Checking size consistency:
Check the sizes and curved forms by means of a templet or suitable measuring means.
Which band saw blade is chucked for small
radii?
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How is a curved kerf
attained?
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