- Shot of a coping saw
- Vertical movement
- An asynchronous motor
- Stable and thick support for installation
- Training needed
- Which blade for which purpose?
- Use a scroll saw: step by step in pictures
- Cups on the fly
- Straight cuts
- Complex cutting with scroll saw
- Cut out plexiglass
- Cut out cardboard
- Cut out metal
Indispensable in carpentry, cabinet making, marquetry or model making, the scroll saw cuts fine and precise cuts, straight or curved, in wood, synthetic thin or soft metal.
Originally, the scroll saw is a manual tool called "bocfil" consisting of a thin blade taken on a metal "U" frame, extended by a wooden handle. This saw, which requires a lot of technique, is still used by luthiers, furniture restorers and marqueteurs.With the technological evolution, the saw has motorized, facilitating the work of cutting and allowing greater cutting thicknesses.
Shot of a coping saw
|06||Pliers of tightening|
|09||Lever of relaxation|
There are two types of jigsaws today: the electromagnetic saw limited to small cutting work (no more than 8 mm thick) and the oscillating arm saw with electric motor. The latter, tested here, offers a real mechanical sawing movement and a great flexibility of work on thicknesses up to 50 mm depending on the models and materials used.
It consists of two articulated parallel arms (up and down) forming a gooseneck. A blade is attached to the ends of the arms.
It crosses a table or a sawing tray (round or rectangular). Driven by an electric motor, the arms ensure the blade a vertical and regular movement like a sewing machine.
An asynchronous motor
The engine does not need to be very powerful: 100 to 180 W are sufficient for this type of device. The best saws (as here) are equipped with asynchronous motors, which are more robust and quieter than universal carbon brushes. Less expensive to manufacture, they vibrate, heat and do not allow intensive use.
The purchase price of this type of machine ranges from 80 € for a first prize and can go up to € 2,000 for very high-end saws for professionals (the model used here, Multicut1 from Hegner costs 500 €). Very inexpensive machines can be of poor quality and offer imprecise work. It is always advisable to try this type of tool before buying it so you do not have a bad surprise.
Stable and thick support for installation
The scroll saw does not really need adjustment except that of the blade tension and for some machines the cutting speed. The user can very quickly focus on the cut to achieve.
The saw must be mounted on a stable stand to prevent vibrations that are harmful to accuracy. Most machines must be well secured (bolts) on a support, preferably thick. Some manufacturers offer as an option a base adapted to the morphology of the saw.
The grip is simple, but you have to practice on the fly or following basic tracings before starting more complex cuts. For early achievements, it is advisable to start with soft wooden puzzles and not too thick (birch, poplar...). If you are not an eminent draftsman, stick a model on the piece to cut.
You just have to follow the contour to make the cut. Plate the piece with enough pressure to prevent it from hopping, but not too much to slow the movement of the blade. Cut-out models can be found in specialized books (creative hobbies) or on the Internet. To buy the wood, consult the yellow pages, section trading wood and sawmills or appointments in a large DIY area (GSB).
Which blade for which purpose?
As with any cutting tool, the choice of blade is paramount. The current blade length is 127/130 mm. There are two attachment systems: clamps or pins. The most common blades have smooth ends and are held in forceps. They offer a great fineness of cut.
Easy to install, the slats with pins are wider and require larger drilling for closed cutouts. Which is not always possible if the room or angle is too small. Avoid machines using this system. Some manufacturers provide very complete tables on the destination of the blades.
Use a scroll saw: step by step in pictures
- Before starting work, it is essential to fix the saw using bolts on a solid and stable basis. The ideal is to have a thick work plan.
- The saw is often delivered with the blade mounted. It is necessary that check and adjust its tension. Tight, the blade gives a clean and clear. Too tense, she can break.
- The blade is held up and down on the arms by two clamps.
- The quick clamping system on the upper arm facilitates the passage of the blade through a hole in a workpiece.
- For change the bladeyou have to free it from both claws.
- Use a wrench to extract it from the lower clamp.
- the reassembly, take care of the good sense of the teeth.
- Place the tips are down.
- For precision work, a good lighting is necessary.
- In a room that has no natural light, opt for a machine equipped with lighting to mount on the top of the machine or take a desk lamp.
- The comfort of use is important. Place the worktop at the correct height.
- The foot pedale (often optional) is essential to free the hands.
The table can rock up to 45°, to make chamfered cuts.
- Loosen the knob to obtain the desired angle.
- Use twisted blades.
- The air of the blow gun is mechanically obtained thanks to the oscillating arm which presses a bellows with each movement.
- The work area is thus permanently cleared.
Some machine models offer two racing positions of the blade:
- by reducing the range of motion of the eccentric.
- by increasing the range of motion of the eccentric.
Cups on the fly
- To make cuts on the fly, sticking a model is the best solution.
- To avoid cutting the original, use photocopies.
- Hold the cutting piece with both hands.
- Place the first hand closest to the plate blade firmly into the workpiece.
- Place the other hand a little further to guide.
- To begin, use rather thin sections of wood.
- For straight cuts, orient the workpiece 1 to 5° to the axis of the blade. Flexible, it tends to move away from the plot.
Complex cutting with scroll saw
- To make a cut on a closed internal shape, a hole must be drilled near the path for the passage of the blade.
- Make a hole as small as possible to avoid damaging the room.
- To get a perfect, straight outside angle, make a loop.
- Take advantage of the excess part of the room to extend the cut beyond the layout.
- To achieve a closed interior angle net, it is necessary to go to the tip of the angle and then go back to redo a loop and take the cut from the opposite side.
Cut out plexiglass
- Plexiglas, like plastic, tends to melt with the friction of the blade. In order to avoid this merger, keep the protective film. It greases the blade and reduces the heat.
Cut out cardboard
- The sheets of cardboard or veneer are too fragile to be sawn alone. It takes them place between two boards of plywood or thick cardboard, fixed together with adhesive.
Cut out metal
- To cut hard ferrous metals, use a specific blade.
- To cut nonferrous metals and not too thick (aluminum sheet, brass, copper), a blade for the standard wood is enough.
- Lubricate (cutting oil) the underside of the plate or blade before cutting.
- The soft and thin metal plates can be glued on a 5 mm plywood board about thick or sandwiched between two cartons.