Machinery

Every woodworking project involves cutting up timber, from initial conversion through to fi nal dimensioning and jointmaking. In larger workshops, the table saw generally takes the lion’s share of the work. However, the bandsaw is often a viable alternative for the home user.

Bandsaws generally have a larger depth of cut compared to an equivalent circular saw, and they also cut a far thinner kerf. They can cut both shaped and straight components, are excellent for joint cutting and intricate work and can also be used to produce veneers.

The disadvantages of the bandsaw are that its crosscutting ability is limited and its straight cutting consistency is generally not as reliable as a table saw. However, if the saw is well-maintained and equipped with a good-quality blade, you should achieve acceptable results.

In this feature we are looking at the smallest bench-mounted bandsaws, primarily aimed at the compact workshop where large timber sections arent often encountered. However, don’t be fooled by their diminutive size, as they’re capable of serious hard work.

How a bandsaw works A bandsaw is a relatively straightforward machine, but to get the most out of it, you must understand how it works and how to set it up precisely. The blade is made from a continuous loop of metal which runs round a pair of wheels. It passes through a slot in the cutting table where the workpiece is placed. To ensure that the blade cuts accurately, it’s held under tension and is supported by guides to stop it twisting or slipping backwards under load.

The guide settings, the blade tension and blade tracking all have a considerable effect on the fi nal quality of the cut. On the cutting table, there’s normally provision for guide fences to be set up to help you steer the workpiece accurately past the blade.

Blade choices The bandsaw can cope with a wide range of materials when fi tted with the correct blade. When choosing a blade, consider both the material to be cut and the shape to be formed. Narrow blades can cut tighter curves, while wide blades are better suited for straight work.

Setting up the saw To replace a blade and set the bandsaw correctly, follow these steps.

1] Disconnect the power supply and open both the top and bottom doors.

2] Loosen all the guide bearings and push them away from the blade.

3] Using the knob on the top of the machine, release the tension on the blade until it can be lifted off the wheels. Wear gloves for this, as bandsaw blades are very springy and can give you a nasty cut.

4] Remove the old blade from the casing and dispose of it.

5] Fit the new blade over the wheels and gently apply some tension. Turn the wheels by hand and set the tracking control (the knob on the back of the top casing) so the blade is running on the centre of the wheel. Increase the tension and spin the wheels again to make sure that the blade is running true. Remember that narrower blades need less tension than thicker ones.

6] Once the blade is tensioned, set the guide bearings. The thrust bearings at the back of the blade should be set as close to the blade as possible without actually touching it. This ensures that when the machine is running but not cutting, the bearing is stationary, but as soon as the workpiece is pushed into the blade, it is defl ected back onto the bearing which should then start to revolve.

7] The side bearings should be set so that their front edges are just below the bottom of the blade gullets and again, as close as possible to the blade without actually touching it.

8] Close the doors, connect the power and run the machine for a moment to make sure that all is well.

Bandsaw problems You can resolve almost all bandsaw problems by replacing the blade and resetting the guides. Blades are easily damaged and become blunt fairly rapidly, leading to inaccurate and inconsistent performance. In particular, cutting curves can cause uneven wear on the blade, rendering it useless for straight cutting. Invest in goodquality blades to get the best performance.

You’ll almost certainly fi nd that the blade supplied with your bandsaw is worse than useless. Manufacturers seem to fi t their machines with very poor-quality blades incapable of cutting with any kind of accuracy. Your fi rst job, on unpacking your saw, should be to remove the blade, throw it away, and fi t a new high-quality one. This will save you hours of frustration and irritation.

Cutting joints One of the bandsaw’s great strengths is its ability to cut joints. Tenons, for example, can be produced rapidly and simply.

Start by marking out your workpiece in the normal way, photo 1. Cut the shoulders first. To do this you should use both the rip fence and the sliding mitre fence. If you don’t have a mitre fence, use a squared board and run it along the rip fence. Place your workpiece so the blade will cut just on the waste side of the line, photo 2. Set the rip fence against the end of the workpiece, photo 3, then position the mitre fence or the squared board against the rip fence and the face of the workpiece, photo 4. Cut the fi rst shoulder, photo 5, then turn the workpiece over and cut the second. Repeat this on any other components as required.

Remove the mitre fence and re-set the rip fence to cut the tenon cheeks, photo 6. Make sure to cut on the waste side of the line, and set the fence so that the waste falls on the outside of the blade, and not on the inside where it’ll become trapped between the blade and the fence. Test the fi t of the tenon in its mortise and make any necessary adjustments.