Fixed Circular Saws
How can you accomplish the seemingly simplest task of carefully sawing fence boards?
Hand hacksaw for a very long time.An angle grinder with a saw blade installed can be cut rather quickly, but this is dangerous for the user (the fibrous heterogeneous structure of the wood often causes the grinder to be pulled out of the hands). And to observe the straightness of the cut with a tool that produces 11,000 rpm is not easy.Jigsaw, the best solution for curved cuts, but for clear and quick straight cuts, which most often have to be done when processing wood, it is inconvenient.
For cutting in a straight line, it does not matter along or across the fibers, parallel to the edge or at an angle to it, a hand-held circular saw is created on a tree. It is used on construction sites, for standard carpentry work, when installing furniture and installing a roof. And the models, with the ability, when turning over, to be installed on the handle and the upper casing (circular saw blades) are popular with visiting craftsmen and home craftsmen.
Ergonomics and constituent parts of the structure.
The electric motor (often with a flat end cap for ease of installation on it), the handles and the upper cover of the saw blade guard are fixedly connected. Movable elements are attached to them: a supporting platform, a lower guard, nodes of a parallel emphasis, adjustment of the angle of inclination, and depth of immersion.
Saw blade protection.
The upper protection hood on all models of electric circular saws is cast from aluminum alloy. Metal will not crack like plastic, in the case of separation from a rotating, at a speed of several thousand revolutions per minute, carbide brazing disk (user safety).It will maintain the integrity of the tool even if it accidentally falls onto a hard surface. And cast in a single billet with the gear case serves for its better cooling at maximum loads, such as sawing raw wood.
The lower part of the snap-in is closed by a movable spring-loaded fence, always striving to return to the position and not giving the user access to the teeth of the disk.
Before starting work, the master fixes the board on the goats and includes a circular saw. Holding with both hands he brings her to the cut line. Mounts the base plate to the surface and easily pushes the device forward. When pressed, the slightly curved front of the lower casing moves away to expose the saw blade.The movement of the tool is carried out by itself, forward and grabbing of the material occurs from the upper surface of the workpiece. At the end, the fence was cut, under the action of a spring it will automatically close, protecting the joiner from accidental contact with equipment.
Handles for controlling and wiring a circular saw.
There are always two of them, for control and pushing. One-handed models do not exist, because when in contact with the surface, the passage of knots, the contact of the disk with a nail, etc. Kickback may occur.The rear is located vertically and usually closed design. Front, either horizontal or mushroom-shaped.
A bracket is preferable. When making inclined cuts and the need to change the position of the hand, the large extension of the handle allows the user to find the most convenient place to grip by adjusting the tool for themselves, rather than adjusting to it.
Must be perfectly flat. With its lower part, it leans and slides over the surface of the workpiece.According to the material of manufacture, it can be cast from aluminum alloy or stamped from a solid steel billet.The first, due to the numerous ribs and reinforcements are considered more rigid. But during deformation it is no longer possible to align them; replacement is required.
Thin-walled (1.5 mm) stamped mounted on a budget inexpensive circular saws. Professional and model changers in a circular machine can have a steel base with a thickness of 2.5 and 3 mm.Ease of use is added by marking rulers located on most sides of the sole.
Why is a proppant knife needed?
With longitudinal sawing of poorly dried, resinous, viscous wood, internal interfiber stresses are released and the already cut parts of the workpiece are trying to return to their original position. They close and try to clamp the body of the disk.
On sawing machines, a sickle-shaped element is installed, increasing in thickness to the rear, which is thicker than the snap. Moving along the cut, he slightly expands it and wedges the cut ends, preventing them from contacting the walls of the saw circle.
The wedging knife of hand-held circular saws is thicker than the base of the disc blank, but thinner than carbide brazing. It is not implemented on all devices and comes into operation only on raw and twisted material, protecting the user from ejection and jerking.
How to cut strictly parallel to the edge or to get several identical blanks? Simple line guidance will not give the required accuracy.
You can fix the bar next to it and pushing the sidewall of the platform into it, move the tool forward. But fixing with clamps is not always possible, and the use of self-tapping screws or nails will leave grooves after itself.
The parallel emphasis has a T-shaped design and consists of a clamping unit mounted on the platform, a ruler and a base plate.
The required distance is set, the sliding ski abuts against the edge, the ruler is tightened with a screw and can be sawed.
The best circular saws have stops with two fixing points, which avoids backlash and ensures strict parallelism.
The mechanism for adjusting the angle of inclination.
Sometimes you need an end face, not perpendicular to the surface, but made at an angle to it. Just by tilting the tool you will not get it, the degree of the tilt must not only be set, but also followed along the entire length.
To perform it on the base plate, from two sides, install vertical semicircular racks with a slot for the latch. They include strips connecting the upper casing.
The value is set steplessly or with quick installation (small recesses) of the most requested angles (0, 15, 22.5, 30 and 45 degrees).
A well-executed mechanism after tightening does not slip during operation. But the accurate setting of the angle of inclination is not trusted in the factory markings, but is checked with a goniometer.
Circular saw blade. What is a changeling?
It is very convenient if you can turn the device over and use it in the form of a mini cutting circular saw for wood.Such models can be easily distinguished by their angular shape: a flat upper part of the body and a rectangular front handle. Due to their stability on the surface and special clamps-clamps that are installed on one side in the casing, and the other fastened to the workbench (always included), they provide stationary installation.
The gaps along the disk, in width and technological cuts in the support sole are removed by installing a panel on top of it (steel plate).As with conventional sawing, the safety of the joiner is also ensured by the lower protective cap.Depending on the design of the circular saw, the maximum weight of the workpiece placed on top of the tool is limited to: 10, 15, 20 kg, etc.
Change of equipment. Which is more convenient?
Professional models have a button or lock lever on the case. Having pressed the saw blade, it stops and with a special key with protrusions, usually the clamping nut has several recesses, it is turned away.
It is most convenient if the shaft is fixed immediately, in any position, without scrolling.
A less convenient way, when the fixing bolt has to be clamped with a socket wrench.And it’s completely inconvenient if you have to lock the snap by installing a screwdriver or block it, leaning on the tool, pressing the teeth to the board.
For a standard key, a place on the upper casing, in the handle or on the bed can be provided.
Submersible circular saw. Features
Not always cut has to be done with the edge. If the task is to get an internal rectangular hole, then it is impossible to carry out accurate cutting not from the end, but from the top of the workpiece with a circular saw.
By setting the disc on the marking and turning on the engine, it will inevitably shift from the path and burrs on the edge. Yes, and a clear vertical lowering manually can not be performed.
The disk design consists of a fixed base and movable protection of the lower part of the saw equipment. The submersible “head” is spring-loaded, and the wide base is motionless. When you click on the case, the disk is recessed strictly down. The first light touch of the teeth of the surface ensures the absence of chips. Return to the initial position occurs automatically.
If you set the immersion depth less than the thickness of the workpiece and make a few cuts, you get a groove.
A straight-line movement of the submersible saw occurs along it (parallel stops are not used).Some disc models are also able to work with rails. They can easily be distinguished by the groove passing through the entire support frame, located on the side opposite to the saw blade.
The tool is put on the tire from above, but does not start from the end.
The size and geometry of the grooves of most rails is standardized and suitable for devices from different manufacturers.
Size range: from 0.36 to 2.6 meters. The connection occurs with a removable butt pad.
Technical characteristics of circular saws and inherent capabilities.
What is the relationship between saw blade size and motor power?
Virtually all other characteristics of the tool, and primarily the power of the installed electric motor, depend on the external diameter of the equipment.
The larger the disk, the deeper it enters the wood and the greater the resistance of the fibers during its advancement.
In the lineup of most manufacturers of circular saws: Yato, Sturm, Makita, AEG, BauMaster, Ryobi, Energomash, Dnipro-M, etc. “Younger” models have an outer diameter of 160 mm, providing a cut to a depth of 55 mm (usually this figure is one third of the diameter).
The most popular 180-200 mm cut into 60-70 mm.The maximum depth, for example, for Titans PTsP18-335 with an external size of 335 mm is 110 mm. Such models, weighing 8 kg or more, are purchased for massive timber, and not for accurate cutting of thin-sheet lumber.
A saw with a more powerful motor will easily pass wet wood, the tool will not stop when it gets into knots and problem areas, and even by increasing the feed, the electric motor cannot be “crushed”.
When working with the weak, you will have to carefully monitor the sharpness of the cutting teeth. When they become dull, the load on the motor increases and it begins to overheat.
Dust removal system and sawdust blowing off from a marking.
Despite the fact that the disk moves from bottom to top and forward from the working one, the flow created by it is not enough to remove the generated sawing waste, which blocks the visibility of the drawn line.
The best circular saws have an integrated chip removal system. The air drawn in by the impeller of the rotor passes through the slots in the inner part of the casing and enhances the flow from the rotating equipment.
You can install a dust bag on a number of models, but most have a nozzle for a vacuum cleaner.
Speed controller. Allows you to change the number of revolutions of the saw blade. It is convenient when working with materials of different structure and features. For example, plastic, tends to melt upon contact with a rapidly rotating disk.
Power On Lock. A button that, when released, will prevent the key from being pressed. Prevents accidental start-up, for example, when changing equipment or technical inspection of a hand saw.
Electrodynamic brake. Sharply locks the shaft when removing the finger from the Start key. Serves for safety and does not allow damage to the surface of the workpiece in case of accidental contact.
Safety clutch. It takes care of the safety of the worker and prevents the tool from moving backward at the time of the reverse impact when the disk is jammed in the wood.
It can work when the saw, bumping, runs into a self-tapping screw or nail. The shaft continues to spin, and the equipment is already disengaged from it.
Laser marker. It is mounted on the protective cover and shows the direction of the cut. It has an adjustment mechanism for adjusting the accuracy of guidance.
It turns on when the start button is pressed.
Power is supplied from the mains, through the electronics lowering voltage or battery cells.