The question is often asked. What kind of bandsaw wheels should I use? Should I use V-belt pulley bandsaw wheels or is solid steel better? The answer is not always black and white, especially if you ask more than one person.
First of all, you must consider what application that you have. When I discuss this topic with customers I always ask, are you going to saw for production or will you saw for hobby? Then my next question is, do you want the best wheels or do you want to save money; In other words, are you wanting the longest possible band life or do you want to cut corners even though you know that you are sacrificing blade life?
There are many types of band wheels used today, and there are many opinions of what is best. I will give you my opinion using physical logic which I have experienced and witnessed.
Let me begin with large diameter bandsaw wheels compared to small. Large vs. Small is relative to the width and thickness of the bandsaw that you are using.
I will always say that larger is better if the wheel is true round and balanced. The most common bandsaw blade used for the portable sawmill is the 1 ¼” wide x .042 thick, when considering this band I would say that a 16 inch wheel is small, and a 19 inch is medium, and a 26 inch is large.
I would not want to build anything in this class below an 18 inch. The 19 inch wheel has been used on thousands of sawmills with good results; they have been proven for the past 10 years. However, I will still say larger has advantages because of anti-clastic curvature.
When considering the 1 ½” x .042 bandsaw blade we are pushing the line to use 18 inch wheels. By pushing the line I am referring to the fact that thousands of sawmills out there are running 18.75 inch bandsaw wheels with 1 ½” x .042 and sawing good lumber every day. I am pointing to the truth that larger will give better results because the bandsaw blade will bend less around a larger bandsaw wheel. We get good results from 25 inch bandsaw wheels or larger.
If considering 1 1/2” x .050 bands, I would not take thought of using nothing less than 26 inch bandsaw wheels. Moreover, 30 inch wheels work well with the .050 thick bandsaw blades.
When you start to consider what is best for bandsaw wheels here are a couple of guidelines to consider when purchasing them.
They must be true round for an even and constant pressure for the band to work.
They must be balanced to eliminate vibrations; band sawmills cannot take harmonic vibrations.
For log sawing band mills, they must be crowned. The crown allows the band to be tracked to run in the proper position on the wheels. The crown has to be enough to allow for some build-up of resin or pitch and still be able to track the band in position.
For resaws I prefer crowned because of the ease of tracking.
Now let us look at the v-belt pulley bandsaw wheels being used today.
V-belt pulleys with a v-belt inserted into the bandsaw wheel: This type of bandsaw wheel is probably used the most by portable band sawmills than any other wheel. Some are used with crowned belts, some with flat belts, and some with a new urethane belt.
How do these qualify when testing?
Bandsaw wheels are not true round. I am looking for a tolerance of accuracy of .005 and I have never found one yet that was even close. Some are out of tolerance as much as .035 to .050. This is never good for the band saw blade body. I find the larger wheels to be out of tolerance to a greater amount than the smaller wheels.
Why are bandsaw wheels untrue, we know they are made on a high production lathe?
A. Here’s why, they’re cast then put on a hydraulic jaw chuck that clamps outward between every spoke of the wheel. Cast steel has to be held firm (without vibrations) to be machined properly. So enough pressure to hold the wheel firm will flex the rim outward between each spoke. Of course it is machined perfectly from the bore to the rim but when it is released then the rim flexes back in. Now you have an untrue wheel with an untrue v-grove. These pulleys work great powering belts that can flex and absorb the vibrations. Band saws are a different matter.
B. The belts have a lump at the point where they are joined, which adds to inconsistent pressure and jolting of the bands while it works. They have to be replaced often, and break down with strong solvents such as diesel fuel or mineral spirits based products. Which causes me to question whether these are inexpensive for the mill owner in the long run.
Why are v-belt Bandsaw Wheels Used?
Because they are inexpensive to purchase and can be bought anywhere. Would I consider using pulleys for band wheels? The answer is, I would never consider them in a production situation. However I would use them on a hobby mill.
At Cook’s Saw we have used them on the manual type mills because we are striving to keep the price of the mill affordable. As of April 01, 2002 for all of our band sawmills, we are using our newly designed solid steel wheel that is crowned and is tolerance to .003 round.
This brings us to discuss steel bandsaw wheels.
What makes a steel wheel better?
1. Steel can only be better if it is true round and balanced with the proper crown.
2. Steel wheels have to be machined properly to be better.
3. Steel is virtually indestructible. When a bandsaw blade breaks it will not cause damage to the wheel. You can use any kind of blade cleaner such as mineral spirits or diesel fuel without damage to the wheel. (These kinds of solvents will destroy a v-belt in a short time). Keeping the band blade and the wheel clean is very important, especially in pitchy type wood.
I prefer steel bandsaw wheels compared to v-belt wheels whenever it’s possible. As of April 01, 2002 on the small manual band sawmill we are using our newly designed solid steel wheel that is crowned and is tolerance to .003 round.
Our bandsaw wheels are true and balanced and affordable. These wheels are 18.75 inches in diameter with a 1” face. They will also retrofit on many other mills that use this size wheel. We have been using solid steel wheels on our AC-36 for almost five years now and we think it is the best choice for sawing logs.
Until Next Time,
aka... the "Saw Doctor"
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