Assembly of a homemade band saw from plywood

Wood is widely used in construction for various purposes, such as building houses and outbuildings with bars, creating floors with boards, and finishing walls. When it comes to sawing lumber at home, many people opt for band saws. However, factory-made band saws are quite expensive and not accessible to everyone. Nevertheless, it is possible to save money by building a band saw by yourself. By customizing the size and installing the appropriate cutting blade, this homemade band saw can also be used to work with metals, alloys, stones, and synthetic materials like polypropylene.

Band saw design

• chassis
• cutting board;
• propellers;
• wheels;
• blades.

The drawing below depicts these components of the device and smaller components with fundamental measurements in a schematic manner.

When it comes to driving, electric motors operating on a 220V network voltage are commonly used. The size of the workpieces being sawed determines the motor’s power requirements, with heavier materials calling for more powerful motors. Three-phase motors designed for 380V can also be used, but this presents additional challenges when connected to stationary networks. Adapting the motor to a 220V network would require the installation of phase-shifting and starting capacitors. Alternatively, gasoline or diesel internal combustion engines can be used instead of electric motors.

The cutting blade is securely fixed onto the pulleys, allowing it to saw the workpieces by moving along a closed oval or circular path.

If you have an electric jigsaw, you have all you need to create a compact desktop machine. The photo below depicts a model that can serve as a guide for assembling the device. With this visual reference, you can easily put together the machine without relying on a lengthy explanation of the step-by-step process.

Crucial! Typically, the dimensions of the generated machinery are reliant on the forthcoming objectives that are intended to be accomplished using its assistance. To convert logs into beams or boards, a unit of significant proportions will be necessary. For individuals who possess apartments with loggias, only a compact tabletop machine will be appropriate.

Preparatory measures

Prior to commencing the assembly procedure, it is advisable to gather the essential supplies and tools according to the blueprint. This will enable you to first ascertain whether everything required for the task is present (any missing items will need to be procured), and also prevent any unnecessary distractions during the process.

Necessary materials and tools

To create a band saw, you will require the subsequent materials and components:

– boards or plywood sheets (or chipboard) to be used for constructing the frame, table, and pulleys;

– sheet steel for the saw;

– channel, metal angles, or wooden bars and laths for creating the support frame;

– bearings;

– steel bar for making the pulley axles;

– electric motor;

– self-tapping screws, bolts with nuts and washers;

– polyurethane glue;

– rubber from a bicycle tube;

– textolite;

– bushings;

– V-belt;

– varnish or paint.

The recommended thickness for the boards is 20mm. It is highly advisable to select durable and hardwood for the lumber.

For the construction process, you will require the following tools:

• drill-equipped screwdriver;
• tool for hitting nails (hammer);
• wrenches (sized for bolts);
• various screwdrivers;
• handheld tool with two hinged jaws (pliers);
• power tool used for grinding (grinder);
• tool for cutting bolts (bolt cutter);
• tool used for sharpening (sharpening machine);
• power tool for cutting various shape patterns (jigsaw).

The manual equivalents of power tools are adequate replacements, although they will necessitate more time and effort for assembly. Furthermore, if metal angles or channels are utilized as opposed to wooden bars, a welding machine and electrodes will be indispensable. Bolted connections introduce additional difficulties with achieving a snug fit between the parts.

Recommendations for choosing a banding blade

Making your own cutting blade can be quite challenging. It requires tool steel of U8 or U10 grades and a flexible saw. The thickness of the saw should be 0.2 to 0.4 mm for soft wood, and 0.4 to 0.8 mm for hard wood. The length of the assembled machine’s blade will be approximately 1.7 meters. You will need to cut out, divide, and sharpen the teeth on your own. To join the tape into a solid ring (in this case, end-to-end), you will need a gas burner and solder. Afterward, you should sand the connecting seam.

Purchasing a pre-made high-quality cutting blade from a store is a much more convenient and time-saving option rather than trying to make one yourself. The width of these products can range from 18 to 88 mm, depending on the material you need to saw. Manufacturers provide a variety of saws based on this criterion:

• Bimetallic blades: these are specifically designed for cutting metal, including stainless steel and other strong alloys.
• Diamond blades: ideal for sawing hard materials such as marble, quartz, and granite.
• Carbide tools: these can be used for machining high-strength alloys.
• Tool steel blades: these strips are perfect for cutting wood.

The final type of band saw is frequently outfitted with machines constructed in local settings. This is because of its affordability and usefulness. However, if you need to work with tough materials, it is advisable to purchase a more robust, abrasion-resistant, and costly saw in order to reduce the chances of the blade breaking.

If you intend to make a curved cut using a band saw, it is important to choose the blade width considering the radius of the curve. The photo below displays some correlations between these measurements.

Hint! To achieve a smooth cut when sawing lumber lengthwise, it is advisable to use broad cutting blades. They enable you to achieve a more uniform cut.

When selecting a saw for woodworking, it is also important to take into account the tooth pitch (the distance between the centers of the teeth). This factor determines the type of wood that can be effectively cut. The tooth profiles listed below are the most common, along with their corresponding markings and recommended applications.

It is important to also give attention to the quality of the teeth’s sharpening. The cutting edge should be sharp and uniform. It is also advisable to inquire with the sales assistant regarding the possibility of re-sharpening and the number of times it can be done. For your own safety, it is recommended to give preference to blades of higher quality.

Note! When selecting a saw for machine installation, it is advisable to opt for universal saws that are suitable for processing wood with varying levels of hardness. This will minimize the frequency of blade replacements when changing the processed material.

Stages of manufacturing a homemade band saw

To simplify the process of constructing the machine at home based on the diagram, the entire procedure can be divided into distinct stages:

• Constructing the frame (also known as the frame or bed)
• Creating the pulleys
• Mounting the cutting blade
• Verifying the machine’s functionality

Prior to commencing the assembly process, it is imperative to determine the designated location for the band saw being built to ensure no issues arise regarding its placement and power supply. It may even necessitate the use of a shed or a designated room for this purpose.

Assembling the frame, table top and boom

The C-shaped frame is assembled by constructing the table top, which incorporates the pulley bar, and the department that houses the electric motor. The fabrication of these components follows the dimensions provided in the accompanying drawing. The assembly process follows these steps:

• A box-shaped frame (cabinet) measuring 42x72x50 cm is created using boards;
• The electric motor is then installed within the frame;

• A rod consists of a bar that measures at least 8 by 8 cm;
• At the top and bottom of the rod, plywood pulley supports are attached, with a suitable distance between them to facilitate cutting workpieces of various sizes;

• Connect the frame to the cabinet;
• Create an opening in the center of the lower pulley support and insert a bushing with two bearings into it;
• Place a plywood table top that is 20mm thick on top, with textolite attached to the working surface and a slot for the cutting blade;
• Add laminate to the sides to facilitate the removal of sawdust and cleaning of the saw afterwards.

It is essential to have a hole in the lower support that includes bearings for linking the motor and cutting belt pulleys. These pulleys will be secured onto a single steel bar shaft. To customize the machine’s height according to your own, you can create a stand that also enhances the stability of the structure. By using welding, it is possible to fabricate a metal frame.

Manufacture and installation of pulleys

The pulleys are manufactured by cutting circles from plywood and then gluing them together to create a 3 cm thick piece. Three pulleys are needed in total: one with a groove for the belt drive, and two for the belt web. The two pulleys for the belt web are made with a convex edge at an angle ranging from 5 to 10 degrees, as shown in the photo below. This design facilitates self-centering of the belt while the equipment is in operation.

The pulley with belt transmission is situated within the pedestal.

Its size is determined based on the number of rotations of the motor being used: it must ensure a speed of 30 m/s for the saw.

One of the pulleys that drives the saw is positioned at the lower part while the other is placed at the upper part. A hole is created at the center of the latter. The bearing is then inserted into the bushing. With the use of glue and wooden strips, it is securely attached in the prepared slot.

The pulley is wrapped with a bicycle tube, which is chosen to have a smaller diameter than the workpiece. This is done to ensure that the webbing does not slip during operation of the machine.

The upper pulley has the ability to move, allowing for the adjustment of tension on the cutting belt. A straightforward lifting mechanism is demonstrated in the image provided. Its primary components consist of a lever attached to a spring, which can be secured at various levels using bolts.

The lower pulleys are secured on a single shaft. A belt is connected to the driving pulley (which transfers movement from the engine to the saw).

Once the pulleys have been mounted, it’s important to ensure they are properly aligned vertically. This can be achieved using washers. The accompanying photo provides a schematic representation of the entire alignment process.

One should consider the fact that the lifespan of the cutting blade will increase and the performance of the saw will improve if the pulleys’ diameter, which is responsible for moving the blade, is larger. A band with a thickness of 4-6 mm is appropriate for parts with a diameter of 40 cm.

Installing the cutting blade and guides

The cutting band is secured to the pulleys. In order to ensure a smooth cut of the sawn timber, the DIY machine is fitted with a guiding mechanism. This mechanism is attached along the side of the blade without teeth. Thanks to the guide, the band will not be warped by the timber being sawn. The easiest way to create this unit is using three roller-type bearings: one positioned on the non-toothed side of the blade, and the other two on its sides. The detailed design of the mechanism is depicted in the photo below.

Note: It is crucial to ensure precise alignment of the guides when attaching them to the support. Failure to do so may result in significant belt shifting on the opposite side even with slight deviations.

For enhanced assembly, consider using wooden slats as stops instead of bearings and installing guides underneath the tabletop. This will create a mechanism similar to the one depicted in the provided image.

For optimal results, it is recommended to position the guides as closely to the workpiece as feasible, with an ideal distance of approximately 4 cm. In cases where the workpiece varies in size, it is essential to incorporate a mechanism that enables the adjustment of the guide’s position, enabling the height to be altered from the table top.

Finishing, setting up and checking the machine’s performance

The upper pulley needs to be equipped with a protective cover during the final stage of machine assembly. This serves a dual purpose: it enhances the aesthetic appeal of the equipment and enhances safety by preventing the web from slipping.

The electric motor needs to be shielded from dust and sawdust using a cover, while also being connected to the power supply through a conveniently positioned start button. To ensure personal safety, it is advisable to either provide power to the equipment from a separate differential circuit breaker or to incorporate a protective disconnection device (RCD) into the electrical circuit.

It is advisable to create a dedicated container for collecting sawdust beneath the work surface. The container should be positioned in a manner that allows for easy and quick access for waste cleanup.

Following assembly, it is necessary to adjust and inspect the vertical band saw to ensure proper functionality. These steps should be performed in the following order:

1. Tighten the band to its maximum tension using the upper (driven) pulley.
2. Verify that the blade is perpendicular to the tabletop at a 90-degree angle.
3. Remove the guides.
4. Conduct a trial run of the machine and perform a test cut, applying minimal pressure to the band. The pulleys should spin smoothly and without any abrupt movements.

Once the test is completed, the guides should be secured in their designated spots, allowing for efficient use under load. Following this, it’s crucial to apply both an antiseptic compound and a layer of varnish to protect the equipment from decay and to prolong the lifespan of the band saw.

For smoother cutting of workpieces, it is advisable to affix a guide rail or a metal corner to the table top. This should be done in a manner that permits easy adjustment depending on the size of the materials being processed.

It’s important to be aware that misaligning the band saw blade can result in severe injuries and can also disrupt the proper functioning of the equipment.

A properly assembled and adjusted homemade band saw can greatly enhance work quality and productivity. Additionally, it offers significant cost savings: cutting lumber into the desired dimensions independently is more economical than purchasing pre-cut materials. Moreover, if the premises are heated using firewood, this DIY tool can simplify the preparation process. However, when working with self-made equipment, it is crucial to always prioritize safety precautions.