How to Cut a Straight Line With a Bandsaw

How to Cut a Straight Line With a Bandsaw

A well-equipped woodworking shop will have, at the least, a table saw and a chop saw/miter saw among its power tools.  Each does what it is intended to do well and plays an integral part in the woodworking process.

A very well-equipped woodworking shop will have a band saw, too.  There are some tasks for which only a bandsaw will do that neither a table saw nor a chop saw can do.  Let’s examine this closely.

What Is a Bandsaw and What Can It Do?

A bandsaw is a power saw that has a long, continuous toothed blade held in a vertical position stretched between two wheels that keep the saw blade circulating continuously.  It is capable of cutting a variety of materials, including woods and metals, which are pushed across the bandsaw platform into the saw blade for cutting.  Materials being straight-cut are guided by a fence that holds the material in place for uniform cuts.

While it is true that bandsaws and table saws can make some similar cuts, neither can replace the other.  Nor can one be improvised with to perform cuts the other is better suited for.  Here are a couple of examples.

Making Curve Cuts With Your Bandsaw

The bandsaw’s strength is in making curve cuts, a task that neither the table saw nor chop saw can make.  While a jigsaw may be the tool of choice for simple curves and odd shapes, it cannot compare with the bandsaw for more intricate curve cuts such as cabriole legs and cutting irregular shapes. 

Cabriole Leg

Making Straight Cuts With Your Bandsaw

Bandsaws are also very useful in resawing wood or ripping large slabs into thinner slabs.  While a table saw might be useful for ripping wood in some instances, your chop or miter saw can’t do this.

For resawing woods (cutting thinner boards out of thicker slabs) with your bandsaw, you will want a fence (a wall against which the slab being cut rests against as it is pushed through the blade) that is as high as the slab being cut.  Positioned parallel to the blade, it will provide the stability and straight needed for an accurate cut.

What Does Bandsaw Size Mean?

Bandsaw size is measured from the blade to the throat (the vertical shaft that serves as the return alley for the blade as it circulates around its two wheels, top and bottom).  This distance determines the largest piece of wood that can be cut safely.  Some band saws come with their own fence, which also affects the size of the board that can be cut.

What Speed Should a Bandsaw Be Run At?

Bandsaws generally run at about 1000 feet per minute.  While wood can be cut well at higher speeds upwards of 5000 feet per minute, slower in this instance means safer.  If your bandsaw is close to the lower range, you’ll get a good cut.

How Tight Should Your Bandsaw Blade Be?

Just like other power saws, a band saw blade needs tension to produce consistently accurate and straight cuts.  This is especially so for thicker slabs and denser woods.  Bandsaw blade manufacturers recommend a tension of between 15,000 PSI (pounds per square inch) and 20,000 PSI for a typical carbon-steel blade.

Troubleshooting Bandsaw Problems

Now that we’ve covered the basics about bandsaws let’s look at some of the more common problems associated with this machine. 

Why Doesn’t My Bandsaw Cut Straight?

When your bandsaw cuts aren’t straight, there are several possible causes, some of which should now be obvious based on the bandsaw information above.

  • A dull blade.  As with any saw, power, or hand, a sharp, good quality blade is essential for a clean and straight cut.  The cure is obvious if this is the cause.
  • Insufficient blade tension.  We’ve noted what that tension should be, and if yours is less than 1000 PSI, the blade strains to cut straight and true.
  • Not feeding the wood properly.  If you force the board against the blade faster than it can cut cleanly, the blade can twist.  The result is a crooked but.
  • Not using a guide.  A guide or fence should be used on all straight cuts for the obvious reasons – – it holds the wood in place and maintains the same width all along the cut.

Why Does My Bandsaw Cut to The Left?

When the bandsaw blade is sharp and set at the proper tension and a guide or fence is used, it does not require a great deal of force to move the board into the blade for a clean and true cut.  Absent all of these conditions – – sharp blade, adequate tension, only enough force to feed the blade at a rate it can handle – – the blade can twist in either direction left or right, and the result is a bad cut.

So, either something is amiss with the bandsaw, or you’re forcing the wood against the blade too quickly for it to do its job.  If you’re sure the bandsaw is proper, it’s a user error.  Back off a bit with the force and let the blade do its job at its own pace with those sharp teeth.

How Do You Get a Smooth Cut With a Bandsaw?

The answer should now be pretty clear.  Sharp, quality blade; the correct tension setting; the right blade speed; use of a guide or fence; only enough force moving the wood against the blade so it can do its job well without twisting.  Follow these cutting tips for your band saw, and your cut will be straight, smooth, and true. 

Portable Bandsaws

Before we wrap up, let’s talk for just a moment about portable bandsaws.  Yes, there are portable bandsaws, and obviously, they are much smaller than the 5-6 foot tall bandsaws you often see in the more well-equipped woodworking shops.

You’ll most likely find a portable bandsaw in a metal fabrication shop, though, not a woodworking shop.  They are used for cutting and to machine steel with a high-performance blade built for that purpose and are typically used in place of a plasma torch or where using a Sawzall is not possible.

Bandsaw Cutting Metal

Portable bandsaws can be used to cut wood, of course.  But, that is not their common use.  They are a specialized tool for more often not a specific purpose in metal fabrications.

The general guidelines for bandsaw use to achieve a straight and true cut are not really different from those applicable to other power saws – – table, jig, chop, skill.  A chef is unlikely to cut himself if his kitchen knives are sharp, and he simply lets the knife do the work.  The same is true for bandsaws.

Sharp blades, proper tension and speed, using a fence for that straight cut and letting the blade do the work will give you what you want, whether it’s simply ripping a thick slab down or making that fancy curve cut on table legs.