If you are a woodworker who enjoys doing intricate scrollwork or inlays, you probably have a scroll saw somewhere in your shop.
These compact little tools can perform amazingly detailed work faster than a hand saw and easier than either a power jigsaw or a bandsaw.
The issue for many woodworkers us just how to judge if the tension on the blade is correct.
Here’s how tight your scroll saw blade should be: Experienced woodworkers tune the tension of their scroll saw blade in a musical fashion. A gentle stroke or pluck on the scroll saw blade will cause a musical note. If the blade sounds “musical,” the tension is probably close to correct.
Like many other things about power tools and woodworking, there is more art involved than science or mechanics.
Learning to turn a bandsaw or scroll saw blade takes time and is a process.
The experience will eventually teach you the feel and sound of a properly tuned scroll saw blade.
Understanding the uses and limitations of the scroll saw is essential as it is with any power tool.
The more you know about your tool, the easier it is to keep the tool working at peak efficiency.
How The Scroll saw Works
A scroll saw is, in its basic form, a specialized form of a jigsaw. The scroll saw uses the same reciprocating motion of the saw blade to cut the material.
There are several differences.
- The scroll saw is stationary. The work moves around the blade on a table instead of the saw moving over the work.
- The blade of the scroll saw is much finer and narrower than a jigsaw blade or a bandsaw blade. A narrower blade allows much tighter curves and more intricate detail work.
- The scroll arm of the scroll saw holds the blade under tension while it is cutting. The tension keeps the blade from wandering and allows much more precise cutting, especially on thinner materials.
It is the tension on the blade that is the most crucial part of setting up a scroll saw to operate properly.
Every manufacturer gives instructions on tensioning the blade on their model of the scroll saw.
Almost every model of scroll saw has a different mechanism to tension the blade.
Following the manufacturer’s recommendations is always the best option when adjusting any tool.
The Musical Method
Woodworkers experienced in using scroll saws have learned a quick trick to judging the tension on their scroll saw blade.
This method does take some practice and, to a certain extent, a bit of musical talent.
After installing a new blade and following the manufacturer’s recommendations on tensioning the blade, many experienced woodworkers will pluck the back of the blade lightly.
When the blade is tensioned correctly, the blade will ring or sound a musical tone. Many woodworkers call this the “High C Test.”
Whether you are musically inclined or not, it should be easy to tell if your band saw blade sounds musical.
If the blade is too loose, instead of a musical sound, you will hear a dull sound. If the blade is too tight, it will not ring but will not sound musical and will not ring.
With experience, you will learn to differentiate the sounds.
For those of you who are meticulous, or a little obsessive here’s a video that will play a tone similar to the one you should hear when you pluck or stroke a properly tensioned scroll saw blade:
It’s All About the Blade
A scroll saw is one of those tools that either works very well or does nothing but pile one frustration on top of another.
The truth is that the blade is more than likely the determining factor in which side of the issue you find yourself.
There are two things that you must get right for your scroll saw to function properly.
Get these two things right, and your scroll saw will be a joy to use. Get either one of them wrong, and you will find yourself beset by problems.
You must select the right blade and set the tension on the blade correctly.
No matter what blade you have chosen for your project, if the blade is not tensioned correctly, the scroll saw will not function to its potential.
No matter what style of blade your scroll saw uses the issue of blade tension is the same.
Each scroll saw the manufacturer has its own means of adjusting blade tension on their saws.
The user manual provided with the saw is generally your best reference for adjusting the tension on your scroll saw blade.
Using the musical method gives you an added reference for proper tensioning of your blade to prevent some of the more common problems woodworkers encounter with scroll saws.
Too Much Tension
Putting to much tension on the scroll saw blade is like stretching a length of kite string too much.
The added stress on the blade amplifies any flaw or weakness in the metal of the blade.
Nothing is more frustrating, or potentially dangerous than having a scroll saw blade break while cutting an intricate interior pattern.
A broken blade can easily destroy a fine piece of scrollwork or inlay in a matter of seconds.
The pieces of the broken blade can become projectiles that can cause injury.
A scroll saw with a piece of the broken blade still attached to the drive motor beneath the table can easily inflict multiple deep cuts or stabs to hands or fingers before you can react.
Too Little Tension
Too little tension on the scroll saw blade has its problems as well. To little tension on the blade allows the blade to vibrate as it cuts.
A vibrating scroll saw blade makes sloppy cuts that tend to wander from the cut line or be off the perpendicular with the saw table.
If you are cutting intricate interior scrollwork or cutting pieces for inlays, precision is critical for a proper fit.
Any wander or vibration in the blade will, at the least, add more time to your fitting and finish or, at the worst, make the piece on which you are working unusable.
IF you can move the scroll saw blade with your fingers after installation and tensioning, the blade should be re-tensioned.
When properly tensioned, the scroll saw blade should resist any movement when gently twisted or pushed with your fingers.
A word of caution at this point is wise. Always make sure that you unplug the scroll saw when installing or tensioning a blade.
You do not want your fingers in contact with the blade should the saw inadvertently start. Practice safe procedures in your shop at all times.
If a scroll saw blade is properly tensioned, it should last from 15 to 45 minutes, depending on the type of material and the operating speed of the saw.
Blade tension is also critical in blade life. Trying to force a saw blade through hard or dense material can cause the blade to overheat and fail.
A blade improperly tensioned, either too loose or too tight, will fail much more quickly.
Properly tension the blade, choosing the right blade, and good saw habits are the key to maximizing blade life.
In The End
Using your scroll saw is the best method for learning its idiosyncrasies and needs. Keep your tools clean and well maintained, and it will perform for you.
Practice good shop safety and follow the manufacturer’s recommendations for maintaining your tool. With a little work, you will be a scroll saw master.