Miter box - from simple to precision, how to use the tool correctly. Making a miter box with your own hands Classification - types of tools

A miter box is a hand-held carpentry tool for precise cutting of boards and other lumber at the required angle. When making a wooden frame, installing platbands and baseboards, or performing any other work related to cutting boards, you will definitely be faced with the need to create a perfect corner cut - the so-called miter joint. In order for the joints of the parts to fit tightly and have no gaps, the cutting angle must be as accurate as possible. Here a miter box becomes an ideal assistant.

There are several design options for this device. In our article we will dwell in detail on the main types of miter boxes, tell you how to choose and correctly use this hand tool to create a flawless burr.

A box-type carpenter's miter box is the classic and simplest design, which is a box with saw grooves located at strictly fixed angles. The tool is used for cutting wooden and plastic blanks at the required angle and creating miter joints.

Modern box-shaped models are made of impact-resistant ABS plastic, less often wood and metal. They are equipped with adjustable clamps for fixing the workpiece, and they also often have a mount for installation on a workbench. The tool is universal. With it, you can make cutting angles in both vertical and horizontal planes. The standard model of a box miter box has grooves for creating angles of 22.5°, 45°, 90°, 135° (in the horizontal plane) and 45° (in the vertical plane).

Advantages: affordability, the ability to fix on any surface, small size and weight for ease of transportation, the ability to cut corners in two planes.

Flaws: the dimensions of the sawn workpiece are limited by the width of the miter box; The accuracy of the bevel is very mediocre, the smoothness of the cut also leaves much to be desired; it is not possible to set the required cutting angle value; Sawing occurs in short movements, which is why the blade often jumps out of the guides, and the work itself takes a lot of time.

Despite all its shortcomings, it is advisable to choose such a tool for household purposes: repairs, household work in the country, etc.

What saws are best to use with a miter box?

Complete with a miter box, a special axing saw is usually used. Thanks to the steel backing, the saw does not bend during operation, which contributes to a more accurate and accurate cut. In this case, the saw blade itself acts as a limiter for the cutting depth.

You can cut with a regular hacksaw, but the quality of the cut in this case will leave much to be desired. The cleanest and most accurate cuts are provided by blades with fine teeth, a high number of TPI (teeth per inch) and minimal setting (or no setting at all).

Rotary mechanical miter box

When there is a need for high precision cutting at any angle in the vertical and horizontal plane, the capabilities of a box miter box become insufficient. In this case, it is advisable to purchase an adjustable mechanical miter box - a precision hand tool for high-precision sawing of wooden, plastic and even metal workpieces of small and medium thickness.

A mechanical miter box consists of a metal frame, a rotary carriage and a saw, precisely fixed in the guides of the rotary assembly. Sawing occurs according to predetermined parameters. The clamping system rigidly fixes the workpiece to improve the convenience and accuracy of sawing operations. Precision miter boxes are equipped with back saws or bow saws, with the ability to adjust the blade tension. Provided that high-quality saw blades are used, a mechanical miter box provides a cut no worse than a miter saw.

Advantages: accuracy of sawing operations; long blade stroke, increasing cutting quality and speed; the ability to adjust the depth of cut and make cuts at any angle; ability to work with workpieces of various lengths and thicknesses; Cut quality comparable to that of a miter saw.

Flaws: By the standards of mass production, sawing operations on such a tool take a lot of time.

Compact magnetic miter boxes

Simple and functional devices for cutting wooden boards at a given angle. They are plastic or metal guides that can be adjusted. Magnets built into the guide attract the saw blade, ensuring its fixation during operation. How to cut an angle with the required number of degrees using such a miter box is clearly shown in the photo.

Advantages: cheap; compactness; accuracy not inferior to a box miter box; possibility of cutting at a given angle; minimum division step.

Flaws: working with boards of limited width; poor quality of cut compared to a rotary miter box; low productivity.

Despite all their shortcomings, such devices are optimal for domestic use. With them, you can always accurately cut trim, ceiling or floor plinths, without the need to purchase a full-size miter box.

Miter boxes for creating dovetails and straight tenon joints

A set of simple metal guides, fixed with a screw clamp, will help in creating a perfect design. The devices allow you to make smooth and precise cuts much faster and with less effort. Magnets built into the body of the product keep the saw in contact with the guide surface, ensuring convenience and precision of cutting.

There are two varieties of such miter boxes: with an inclined guide surface for creating dovetail joints and with a right angle for cutting straight tenon joints. The wood between the tenons is removed manually using a sharp chisel.

A miter box is one of the tools that is practical to use and can be useful for construction and repair work. This article will talk about the features of the device, the scope of its use, and also describe the improvised manufacturing method.

What is a miter box and what is it used for?

A miter box, as a rule, is an additional tool that is used when working with different materials, where you need to cut an object at a specific angle. There are different types of tools:

standard;
turning;
electric.

So, let's look at the characteristics of each type.

The simple-shaped tool is a tray with grooves at the ends for a saw. This design helps to accurately cut the installed area at a specific angle. In the standard form, the miter box is designated 45 degrees and 60, which is most often used in construction.

There are other variations of the miter box that are intended for professional work. One of the variations is a rotary miter box. This shape helps to cut an object with maximum accuracy and minimal deviation. Such a miter box has a stable base and a rotating part fixed on it, which is a guide element for the saw. This part can be fixed up to 1 degree, which helps to cut the object accurately and accurately.

One of the most expensive and complex variations is the electric miter box. In its form, it consists of two parts: an electric saw and a rotary miter box. Expensive and professional examples are marked with laser markings. This type of miter box helps to make an extremely precise cut of objects in a minimum amount of time.

In fact, it can be identified that this tool is used in carpentry work. Its shape represents a certain template, which is intended for cutting material at a certain angle. The most popular method of application is a miter box for baseboards, as well as floor and ceiling ones. With the help of the tool, the worker can confidently spray elements made of plastic, wood, plastic, and cable ducts.

The process of using a miter box in practice is not that complicated. First of all, you need to place the object in the middle of the tool and carefully cut it with a hacksaw at the required angle. But still, in any work there are nuances and features. Before starting sawing, you need to decide on the angle of the cut: internal or external. Of course, every worker or builder is capable of making such a tool himself. The process of making a miter box is simple and does not take much time or materials.

Advantages of a homemade miter box

Anyone can purchase such a tool in a store for a small price. But, a homemade design has its advantages and features:

the ability to create a multifunctional tool with different angle appearances;
strong material is used in production, which helps the product last for many years;
fast manufacturing method;
minimum number of consumables;
making the tool will cost free if you have old boards from a previous renovation at home.

The only unique feature of a homemade tool is to make the correct calculation for marking the angles.

List of necessary materials and tools for work

Making a miter box with your own hands is not that difficult if you follow the recommendations of experts. First, make sure that the materials prepared for work are sanded. To make a miter box, it is important to choose wood that must be dried, without dents, and have a smooth surface without any defects. You should not choose plastic as the starting material, because it is not strong and therefore can easily be damaged during work. The boards made for the tool should be about 2 centimeters thick.

Before starting work, you should prepare the following devices:

Ruler and pencil;
fine-grained skin;
hacksaw for metal;
vice;
drill with a different set of drills;
European screws (confirmed);
a hacksaw with small teeth, designed for sawing skirting boards.

All of the above tools should be sufficient to carry out the work. Among the additional accessories, a hex wrench may be useful, with which it will be easier to tighten the confirmations. Also, before starting work, it is worth preparing individual elements for a homemade tool. Before we begin describing the instructions: how to make a miter box with your own hands, let’s pay attention to a detailed inspection of the manufacture of parts for the device.

Choosing a saw or hacksaw for a miter box

First of all, before starting work, you should choose a hacksaw for the job in order to make a miter box. Actually, choose a miter box for the hacksaw, and not in the reverse order. A good and high-quality saw should have the following characteristics:

have a thin blade;
small teeth;
good cruelty.

The presence of small teeth makes sawing wood neat and without flaws. The thin blade adds confidence that the material will be cut exactly along the line. Blades that are too elastic for a hacksaw are a significant drawback. It can be eliminated with a butt - a special rib of strength and rigidity. Miter box hacksaw - photo shows all the features of this blade for the tool.

For sawing skirting boards and polyurethane, it is recommended to choose a metal saw. Such a tool has a perfectly smooth and thin blade, as well as the necessary rigidity, which is obtained by tensioning the blade. Also, a hacksaw for metal may be suitable for spraying template cuts, and in the beginning of the work of making the device.

Preparing the side walls for the miter box

Parts of plywood or scraps from boards are used to make side parts for the miter box. To ensure a high-quality tool, you should adhere to precise measurements and recommendations:

the approximate dimensions of the side walls should be 10 millimeters for plywood and 20 mm for boards;
their height is selected from 30 to 50 millimeters, depending on the purpose of the tool (30 mm is recommended for ceiling plinths, and about 50 mm for wooden ones);
The length of the side walls of the miter box should be 250 mm or more, but it is not recommended to lengthen it too much, since it will be inconvenient to perform the work. As an exception, a longer miter box length can be used, but this is only for massive objects.

After measuring the side parts of the boards, we cut out two absolutely even and identical elements. This is very important for further cutting of boards and marking them with tools. In the prepared instruments we make notations at the bottom for confirmations.

How to properly mark for miter box cuts

Answering the question: how to make a miter box? - it is important to first determine the markings for the cuts, after which you can begin the last stage of work. So, the process of making markings is as follows:

1. Place two manufactured side walls together.

2. We check all the edges, which must coincide exactly with each other.

3. Using a vice, we connect two workpieces.

4. Find a point in the middle of the line and mark it with a pencil or marker.

5. Then we measure an angle of 45 and 90 degrees on opposite edges.

6. Let’s start making diagonal cuts using a hacksaw. This device has small teeth, which will ensure an even and neat cut.

7. For direct spraying, the cutting depth must be significant so that you can continue working with a carpenter's hacksaw. We make the cut only to the base of the miter box, but not deeper.

8. Using the same method, we make another slot perpendicular to this one, which is important for smooth cutting of the edges of the plinth.

9. After everything, use sanding paper or a file to clean the cuts from debris.

Making a miter box: the last stage

At the last stage of work, it is necessary to connect all the workpieces:

1. We will attach the side parts of the blanks to the base so that the end area of the guide boards can be connected to the side ones.

2. Using a drill, we drill holes according to the previously formed marks. It is better to use drills with different diameters for the drilling process rather than using one stepped drill designed for confirmations. Using larger diameter drills, we first form an area for confirmation, and using a sharper drill with a specific thread, we make a hole of the required length at the base of the end.

3. Using confirmations, we tighten all the details. For better convenience, you can make a hole in the middle of the tool and connect it to a table or other flat surface.

5. You can make cuts at the base of the device, which are used as marks for convenience during work.

Definitely, almost anyone can make a corner miter box, but in any case it is worth taking into account the nuances and features of the work. For example, if you want to make the instrument collapsible, then it is enough to secure it with confirmations, and the use of glue is not necessary. For professional and stationary work, it is better to attach the tool to a surface, such as a desktop.

When the work load is high, it is worth attaching a piece of material, for example, rubber, to the back of the working surface, which will not allow the tool to move. During the manufacturing process of the tool, it is worth correctly calculating the width of the base. Typically, this depends on the size of the materials being processed.

Rules for using the miter box

To learn how to use a miter box at work, you do not need any specific skills or abilities. Learning the option of sawing corners is not that difficult, and all the knowledge will be useful to you in repair work around the house.

Making a miter box is only one part of the job. To learn how to accurately spray parts, it is important to use the tool correctly in your work. Those who are dealing with cutting corners for the first time need to learn how to measure corners. To improve your skills, you can first practice on samples made of wooden and polyurethane skirting boards.

Attention: When using a miter box, you need to remember some details and operating features. After all, it is worth considering that the plinths that are connected must have two sides - right and left:

the right side is accordingly placed on the right side of the plinth, and the corner to be sawn off is on the left;

The left side of the plinth is placed in the tool on the left side, and the corner for sawing is on the right side.

This rule is intended mostly for beginners, but still you should not ignore it in your work.

The second rule is to apply pressure to the sides of the miter box, that is, it is necessary to determine whether the object being cut will be placed closer or further from the master. This adjustment should be considered using examples and mistakes made by employees.

There are four main mistakes that workers make when using a miter box with a hacksaw incorrectly.

1. The first mistake is inaccurate alignment of the baseboard. In most cases, this leads to the fact that the cut corners of the skirting boards are uneven among themselves. To avoid this mistake, it is worth dividing the plinth into certain parts, and adjusting them along the periphery, and not at the corners, taking into account straight inserts.

2. The second error arises as a result of confusion in the definition of external or internal angles. For nala, it is important to mark the object, with marks applied at the appropriate corners. After that, you need to connect the marks with the grooves on the tool, secure the baseboard and spray it.

3. The next mistake is the incorrect cut of the skirting boards for the ceiling. They are opposite to the floor skirting boards, and therefore it is necessary to saw them in reverse.

4. The last mistake is that after cutting the skirting boards at the exact angle, they do not match. Thus, it is worth securing the object in the instrument in the same way as it is located on the ceiling.

When working with a rotary miter box, you must follow the same instructions and recommendations, regardless of the angle set.

Using our tips and recommendations, you can easily make a homemade miter box without any extra effort. We hope that the instructions and explanations we provide will help make your work smoother and will be useful to you in practice.

A hand miter box is a very practical tool that can come in handy not only during repairs, but also in construction. What this device is used for, how to use it and make it yourself, you will learn further.

and what is it used for?

So, the presented tool is used in carpentry work. This is a kind of template, thanks to which you can cut any material at a given angle. Most often it is used for processing floor and Thanks to the miter box, you can cut wooden, plastic, plastic elements, cable ducts.

Using such a tool is quite easy: you just need to put the element inside the miter box, secure it and cut it at the desired angle with a fine-toothed hacksaw. However, this work has certain nuances. For example, you must decide which corner you need: internal or external.

You can build such a product yourself, and you don’t have to spend a lot of time and material.

Advantages of a homemade device

You can buy such a design in a store, and it is inexpensive. However, a homemade miter box with a hacksaw has certain advantages:

You can build a structure of different sizes, with different types of angles;

The most durable material is used for work, which allows the product to be used for more than one year;

Fast production;

Minimum source material;

The device can be made almost free of charge, if, of course, you have wooden boards left after any repair or construction.

The only nuance in the manufacturing process is the correct marking of the corners.

What tools and materials are needed for the job?

First of all, keep in mind that all materials must be carefully processed and prepared for work. Most often, wood is used for manufacturing, which must be well dried (so as not to warp), smooth, and free from cracks, chips and other defects. It is not recommended to use plastic, as it is not very durable, and if it breaks, such a product can be thrown away.

The thickness of the boards for the product must be at least 2 cm.

Before making a miter box, collect all the necessary tools:

Pencil, protractor and ruler;

Fine-grained skin;

Drill with drills;

Confirmations (Euroscrews);

Hacksaw with fine teeth (for cutting skirting boards).

In principle, these tools are quite sufficient. Naturally, you will need a hex wrench, thanks to which you can tighten the confirms without any problems.

Making the product: step-by-step instructions

Before making a miter box with your own hands, prepare the components for work. To do this, you need to cut out elements of the required height and length from the boards. Here you need to consider what size skirting boards you will process.

It’s not difficult to build a miter box with your own hands, you just need to take the correct measurements and markings. So, let's get to work:

The prepared parts must be carefully sanded so that they are smooth and fit tightly together.
Now you can mark future cuts. To do this, use a ruler, protractor and pencil. The process must be treated very responsibly, since the quality of processing of the skirting boards depends on it. In order for the marks on both sides to be the same, they must be accurately applied to each other. All cuts must match exactly. You can fix the sides with a vice.
Next, we make a mark in the middle of the elements: it is from this point that the corners will be laid.
Now you will need a protractor to work. Using it, we set angles of 45 and 90 degrees on both sides of the central mark.
After finishing the marking, you can start cutting the holes. For this you need to use a hacksaw for metal. The fact is that it has very fine teeth and will make the cut as smooth as possible. Then it can be expanded a little using a hacksaw. The depth of the cut should be slightly more than half the miter box. Please note that the inner surface of the slots must be perfectly smooth, so it must be sanded.
The last step is to cut out the base of the tool and attach the side parts to it. Confirmats or glue can be used to fix the elements. In addition, for greater strength of the product, it is advisable to use both fastening methods simultaneously.

This is how you make a miter box with your own hands.

How to choose the right saw for a tool?

The saw is an integral part of the presented product, so the miter box must be designed taking into account what kind of cutting blade will be used in the future. It must have certain properties: be rigid enough and not bend, have a small thickness and fairly small teeth. The canvas can also be wide or narrow. The second option must be equipped with an additional stiffening rib, which will prevent the hacksaw from bending.

You should also take into account the material that you will be sawing. For example, for polyurethane skirting boards, a fine-toothed one is better. It is good if the hacksaw has a durable and comfortable handle. Otherwise, you will get tired quickly.

As you can see, anyone can build a miter box with their own hands, but you also need to consider some of the nuances of the process. For example, if you want to make a dismountable tool, then you should not use glue to hold the parts together. It is enough to fix all the elements with confirmations.

If the tool is stationary, then it must be well attached to the base platform. That is, holes are made in the base of the product, and it is firmly screwed to the table. However, if you want the device to be able to move freely and not ride on the base surface, then you can nail a piece of rubber or other material to the underside of the miter box that will prevent the tool from sliding.

During the manufacture of the tool, you need to correctly calculate the width of its base. It also depends on the size of the products that will be processed. Now you know how to build a miter box with your own hands. Good luck!

Miter box- this is a tool device in the form of a U-shaped tray with side slots for a saw, designed for sawing slatted material at a given angle.

When installing floor or ceiling plinths, door frames, laying electrical wiring in cable ducts or manufacturing furniture, it becomes necessary to saw the material into pieces of a given length at a right angle or a 45 degree angle. You can, of course, cut the material along the line drawn using a square. But in this case, the work requires care and it is easy to make an irreparable mistake.

To increase the productivity and quality of sawing, a simple device called a miter box was invented. The photo shows an industrial plastic miter box, with which a hand saw can be used to cut slats, bars, corners made of wood, chipboard, MDF, plasterboard, plastic and other soft materials at an angle of 45° and 90° with sufficient accuracy.

It is enough to mark one point on the rail that needs to be adjusted to size, insert the rail into the miter box so that the mark is on the line of the guides, and use a hand saw inserted with a blade into the slots to cut the rail. The miter box will not allow the saw blade to move to the side and the end of the rail will be the required one.

Industrially produced plastic miter boxes have a significant drawback: due to the larger width of the guide slots and their rapid wear by saw teeth, the accuracy of the angle is low and gaps up to one millimeter wide often remain at the junction of the baseboards or platbands. There are high-precision miter boxes on sale, which even provide the ability to change the angle within any limits, and there are clamps for fixing the material being cut. But they are very expensive, and for one-time repairs in an apartment it does not make sense to purchase such a device. Moreover, a high-precision miter box can be made with your own hands in a couple of hours from scrap material.

To make a homemade miter box, you will only need a couple of metal, preferably aluminum, plates 1.5-2 mm thick and a board for the base of the miter box about 10 cm wide made of wood, chipboard or plywood.

Making a miter box with your own hands

The dimensions of the parts are not important. But the wider the board, the more accurate the cut will be and the ability to cut wider slats. The width of the miter box should not exceed half the length of the hacksaw blade, otherwise sawing will be inconvenient.

Making a miter box begins with cutting out the parts and marking them. In the middle of the board of the base of the miter box, a straight line is applied at right angles to the side walls. A perpendicular line can be drawn using a special square or taking any sheet of paper folded twice.

From the ends of this line, at a distance of half the width of the board along its length, marks are drawn, which are connected by line segments with a marker. The result was lines located at an angle of 45˚ and 90˚ relative to the longitudinal side of the board. But the main one on the base is the perpendicular line, relative to which the side walls of the miter box will be oriented during installation.

On both side walls, in the middle, as well as on the base, first apply along one perpendicular line. From them, at a distance of half the width of the base, for me 5 cm, two more parallel lines are drawn. Marking is done using a ruler or caliper. Here you need to try to draw the lines accurately, since the accuracy of sawing the material will ultimately depend on this. It should be noted that the wider the base board, the higher the cutting accuracy will be.

Next, you need to draw a section of each wall that will be adjacent to the base of the miter box. Since my base is made of chipboard 18 mm thick, I need to draw a strip 18 mm wide. Draw a line in the middle of this strip and mark points on it at an equidistant distance from each other for drilling holes for self-tapping screws.

To prevent the drill from running away at the beginning of drilling, small indentations are made at the designated points with a core, then holes with a diameter of 4 mm are drilled and if the screws have a countersunk head, then it is better to make a countersink, although this is not necessary.

The next step is cutting grooves in the walls of the miter box. The strip must be fixed in a vice or using clamps on a table and cut along the marked lines with a hacksaw. The middle line is sawn at an angle of 90˚, and the outer lines at an angle of 45˚. High precision is not needed here, but it is advisable to do this work carefully. The cut should only reach the line where the walls are attached to the base of the miter box.

Since the base made of chipboard is a soft material, self-tapping screws with a rare thread pitch are best suited for attaching the walls. Although you can use any that are on hand, 25-50 mm long.

After making the base and walls, you can proceed to the next step, assembling the miter box. To do this, you need to accurately align the middle cut in the wall with the perpendicular line on the base of the miter box, pierce the hard wall of the side edge of the chipboard with an awl and tighten the screws. It is better to drill a hole in plywood with a diameter equal to the diameter of the internal thread of the self-tapping screw to the depth of its length.

It is convenient to assemble the miter box by securing its base with clamps on a homemade table for repair. Thus, the lower end of the side wall can be easily aligned with the lower surface of the miter box base.

During a test sawing in a miter box at an angle of 45˚, it turned out that the hacksaw blade moved tightly and rubbed against the walls of the cuts. I had to sharpen them a little with a flat file.

I made the side walls of the miter box from aluminum alloy, but they can be made from plywood or any other dense sheet material. The thicker the side walls, the longer the miter box will last.

Examples of work using a miter box

The miter box constantly helps me cut slatted material efficiently. For example, when laying electrical wiring, it may be necessary to cut the cable channel at a right angle and at an angle of 45˚.

To do this, it is enough to place the cable channel on the base of the miter box, resting it against the far wall and, using a hacksaw for metal, accurately saw off the required section.

After removing burrs from the walls at the cutting site, the parts fit together with virtually no gap.

The miter box is also great for sawing foam ceiling plinths. Thanks to the fine teeth of a hacksaw file, the end of the plinth is ready for joining without additional processing.

In the same way, the ceiling plinth is sawn at an angle of 45˚. It can be rotated in any way and create a tight fit on both internal and external wall corners.

A miter box is also indispensable when installing floor plinths. You can not only saw off the required lengths of the plinth, but also, when adjusting, shorten the plinth even by one millimeter, which is almost impossible to do without a miter box.

As you can see, a miter box is a necessary device for obtaining high quality work with minimal effort. I advise you to definitely buy or make a miter box with your own hands; it will be useful not only when renovating an apartment. Using a miter box, you can make a frame for a photograph or painting, or saw through a plastic pipe when performing plumbing work. It’s even difficult to list all the cases of using a miter box by a home craftsman.

During construction or repair work, it may be necessary to cut the part at an angle of 45 degrees. For example, when installing ceiling plinths that are attached to external and internal corners. If you do not have a special tool, this process can be difficult and stall the entire activity. In this case, a homemade miter box will come to the rescue.

Of course, you can not bother, but simply go to the store and purchase the necessary tool, but only miter boxes made of plastic are available for sale, which are fragile and high cost. After making several cuts, you will notice how the grooves of the tool have widened, and it will simply not be possible to do the job efficiently at an angle of 45 degrees.

Manufacturing

The problem can be solved quite simply by making this tool yourself, spending a minimum of time, effort and materials. Also an undoubted advantage is that you yourself can determine the length of the miter box, which is important when making long elements, such as baseboards or platbands.

Note! The design of the miter box provides for the presence of guide slots in a wooden or plastic tray. In some cases, a straight groove can be made for sawing boards. A more complex mechanical version of the miter box is equipped with built-in stops and clamps. In addition, the kit includes axle and bow saws.

Usage

Using a miter box should not cause any difficulties: marks are made on the material in the required places and placed in the tool so that the markings perfectly coincide with the slot along which the cut should be made. Thanks to the walls of the miter box, which act as guides, the material will not move and the cut will be accurate.

Production technology

The material for self-production is wood, since production from plastic is only possible in industry. It is necessary to choose a hard type of wood; in extreme cases, use a coniferous board, but with a thickness of at least 2 centimeters. If you use ash or oak, then the thickness can be reduced to 1-1.5 centimeters. The workpieces must be perfectly flat with angles of 90 degrees.

Wooden miter box

The width of the tool bed is selected based on the workpieces used. As a rule, the width of the plinth is 150 mm, so the size of the miter box should be made the same; the sides are made the same size, otherwise you will experience discomfort when working with a cutting tool, or the saw will jump out of the groove.

Initially, a box for the miter box is constructed by fastening the elements with self-tapping screws and additionally gluing dowels. After securely fixing the screws, it is necessary to additionally secure the elements of the miter box using a clamp. If excess glue appears, remove it with a cloth. The tray must be left until completely dry.
The next step is to make the markings. A perpendicular line is drawn on the end side of the miter box and the same is made on the opposite side. Next, the width of the miter box is measured along with the sides. An indentation is made from the finished marks equal to the width of the box. By visually projecting all the marks onto a flat surface, you should get a square.
Double-check the marks made several times, since it is the accuracy of their execution that will affect the quality of work and the evenness of the cuts made. Check several times that the distance between the markings is accurate and that they are parallel.
Then, using a sharp hacksaw, make diagonal slits along the sides of the miter box. Do this carefully, observing all marks. To widen the made slots, treat them with coarse sandpaper folded in two layers. If a perpendicular groove is required, follow the same steps.

This tool is absolutely not difficult to use, you just need to take into account some rules:

If throughout the entire manufacturing process you strictly followed the technology, a miter box made by yourself will not be inferior in quality to a store-bought tool. In addition, you can make more than one such tool to make it easier to work with various materials and elements.