Pinewood Derby Stories and Photos from Maximum Velocity
Shop Talk: Choose the Right Band Saw for Pinewood Derby Cars
By Randy Davis
Several years ago, I was asked for a recommendation on purchasing a power saw for pinewood derby car work. The person was thinking of purchasing a scroll saw, which is a saw with a fine blade that moves up and down, and is intended for detailed scroll work (see Figures 1 and 2).
But, while a scroll saw can be used for pinewood derby work, I prefer to use a "band saw". A band saw uses a wider blade, formed into a large band, which cuts through the 1-3/4 inch pine block with relative ease. Although it cannot create the level of detail of a scroll saw, a band saw is more versatile.
The rest of this article will focus on band saws, but before that, you should be aware of the following:
1. A scroll saw is generally safer to use than a band saw. Since a band saw cuts more aggressively, it can do more damage to fingers. But both saws must be used with care, and improper use can result in injuries on both tools.
2. A band saw cuts more quickly than a scroll saw and a band saw can handle larger material. But it cannot perform intricate cutting like a scroll saw.
3. A band saw can be equipped with a fence which allows greater accuracy for making straight cuts.
4. If set up improperly, a band saw will not cut as cleanly and accurately as it should. So make sure to set up the tool properly. Instructions can usually be found in the owner's manual, but I do plan to write on an article on this topic in a future newsletter.
5. When using a band saw, always wear safety glasses, tie up long hair, remove any loose jewelry, and avoid loose-fitting clothes.
BAND SAW SIZE
The first decision to be made is the size of the machine. Band saws are measured by the diameter of the two wheels that propel and guide the blade. Typical sizes are 9 inches for a bench top model, and 12 or 14 inches for a table mounted model.
Figure 3 - Inside a Band Saw - 12 inch Table Mounted
Generally, a larger machine provides more power and can accept larger width blades. But for casual pinewood derby work, a smaller machine is fine. Just don't get a real cheap tool. As with any tool, a cheap tool will break more quickly and doesn't provide as much accuracy.
For example, Sears offers a 9 inch model for just over $100. It will take up to a 3/8 inch blade, and has an optional fence. A step up is a 12 inch from Jet (Figure 3), which accepts up to a 1/2 inch blade.
Figure 4 - Sears Band Saw
(Photo source: sears.com)
The width of the blade affects the cutting speed and the diameter of the curves that can be cut. A narrower blade allows tighter turns and more intricate cuts, but speed is sacrificed (narrow blades have more flex, so cutting speed must be reduced). Wider blades do not allow tight turns, but increase cutting speed. Generally, if you plan to mostly make straight cuts, or cuts that have only moderate turns, then use a 3/8 or 1/2 inch blade. But if you want to make more intricate cuts, then use a 1/4 inch blade.
Band saw blades have different teeth configurations including the number of teeth per inch, and teeth style. The number of teeth per inch (TPI) affects the smoothness of the cut and the cutting speed. Fewer teeth per inch gives a greater cutting speed, but a rougher cut, while more teeth per inch gives a smooth cut, but slower speed. I generally use a 4 TPI blade, which seems to work well on pine blocks.
Blades are available with Regular, Skip, and Hook Teeth. Regular teeth provide a smoother cut, but work best on thin material. For pine blocks, Skip Teeth blades work better.
Blades also have a "Set". This specifies the way the blade teeth alternate. Either "Raker" or "Alternate" sets work fine for pine blocks.
BAND SAW FEATURES
Band saws come with several optional features that affect the performance of the machine.
- Guide Bearing Wheels versus Guide Blocks -
Better machines come with metal wheels with bearings to guide the blade, while less expensive machines use guide blocks (see Figure 6).
Figure 6 - Guide Bearing Wheels (top) vs. Guide Blocks (bottom)
(Photo source: allbandsawblades.com and toolmonger.com)
Either guide system will work, but the guide blocks wear down, so they must be adjusted on a regular basis, and will need to be replaced at some point.
- Blade Quick Release -
Some machines come with a quick release for the blade. This handy feature speeds up the blade changing process. If you plan to stick with one blade type, then it isn't really needed, but if you switch between multiple blades, it is a time saver.
- Dust Collection Port -
Most band saws are equipped with a dust collection port. Attaching a dust collector (or shop vacuum) will greatly reduce dust in the air, which is better for you and for your shop. Smaller machines generally have smaller ports which can readily be adapted to a shop vacuum, while larger machines have larger ports, which are intended for use with a dust collector.
- Light and Air Blower -
Other band saw features are a work light (make sure to use an appliance bulb), and an air blower. The air blower directs a stream of air onto the cut to keep dust from building up on the surface.
There are many choices to be made when shopping for a band saw. If you only intend to use the machine for pinewood derby work (and maybe a few small projects), then a small machine with a few features will certainly work. But if you plan to use the band saw on a more regular basis, step up to a larger machine with more features.