On a machine with screw over spring tensioning, the most common on smaller machines, only really dependable way to set the blade tension is with a blade tension gauge. The machine manufacturer will provide a chart showing how much blade force is generated by any air pressure, and the blade tension in typical blade sizes. Over tightening the blade will shorten the life of the blade wheel rubber, bearings, and blade.
The jig works by measuring the amount of stretch in the bandsaw blade as force is applied by the bandsaw tension spring. Every 0.001″ of blade stretch is equal to 5,800 psi of tension over 5″ of blade. “When resawing, blade manufacturers recommend a blade tension of 15,000 psi. Therefore, you would need 0.0026” of blade stretch in order to reach the recommended amount of tension.
“Every bandsaw and setup has to be treated differently but few understand this simple concept. The discussion here is the OP has a quality bandsaw and is trying to use a 1” blade his saw can’t really handle, that pushes it to limit. Every bandsaw manufacture that supplies to a potential hobbyist buyer will put the disclaimer in to detension to cover their butt. Even with heavy cutting the blades don’t get very hot and the minimal heat they develop has very little effect on the rubber.
Using the improper blade for a task can also kill the blade faster. Don’t use a 10TPI blade for resawing. If you were making bandsaw boxes and had your guides fairly tight, trying to cut tight curves and not allowing the blade to flex, you probably removed a bit of the set of the teeth too.
“To find the correct tension, you can start with the tension scale on your saw, but you will probably need to fine tune the adjustment. With the saw unplugged, increase the tension on the blade until pushing on the side of the blade with your finger using a moderate amount of force deflects the blade about a 1/4” from its normal position. When too much tension is put on the blade, premature blade breakage and poor tracking can occur, but most important, you can damage your machine by trying to make it reach a blade tension greater than the machine was designed to operate at. The answer is yes, so be careful not to over tension your bandsaw blade.
The level of tension a blade can withstand is gauged by measuring the amount of force per cross sectional area of the blade, expressed as PSI. How to Set Blade Tension. Carbon blades: The typical tension applied is around 15,000 to 20,000 PSI. Bi metal blades: Require a greater amount of tension to be applied but should not be more than 35,000 PSI. Two blades of different sizes will require different forces to achieve the same PSI. For example, a ½” x.025 blade requires 312.5 lbs of force to achieve 25,000 PSI. A 1″ x.025 blade requires 625 lbs of force to achieve the same 25,000 PSI, twice as much force. The machine manufacturer will provide a chart showing how much blade force is generated by any air pressure, and the blade tension in typical blade sizes.
do bandsaw blades stretch Related Question:
How long should a bandsaw blade last?
On average your bandsaw blade should last 6 months to as long as a few years depending on what your cutting with it. Make sure to match your blade strength and quality to the project and material your cutting.
Should I release the tension on my bandsaw blade?
Release blade tension when not in use. That helps prevent blade stretching and deforming the band saw tires, which are likely made of rubber or urethane. A stretched blade will cause the operator to increase blade tension to compensate, increasing blade break risk.
How tight should a sawmill blade be?
For carbon steel toothed blades (cutting blades) this is typically 15,000 to 25,000 PSI. Slitting type blades typically are tensioned in the range of 12,000 to 20,000 PSI. In general bandsaw blades are never tensioned past 35,000 psi.
Why do bandsaw blades break?
Machine Defects Even the best blades can fail if there is something else wrong with your bandsaw, and even a small misalignment of bearings or guides can put a twist in the blade as it goes around. Resulting in tension being applied in all the wrong ways which will lead to early breakage.
Are bandsaw blades worth sharpening?
Since a carbide-tipped bandsaw blade will cost well over $100, spending a third of the cost of the blade (or more) to get it sharp and working like new again can make financial sense. However the majority of bandsaw blades, the Wood Slicer included, are not worth spending money to have sharpened.
How often do bandsaw blades break?
Some can last under six months, and some can last years! Some of the most important variables to consider are what you are cutting, the condition of the machine and blade, how long you are using the blade, and even how you are feeding the wood through your saw as well.
How many times can a bandsaw blade be sharpened?
It often makes sense to replace a dull blade with a new one, but you can sometimes get the best value out of merely sharpening an old blade instead of replacing it altogether. You should typically be able to get two to three sharpenings before you need to change your blade completely.
How much tension do you put on a bandsaw blade?
Bandsaw blades require tension and lots of it to consistently produce straight, uniform cuts, especially in thick or dense stock. Most blade manufacturers recommend 15,000 psi to 20,000 psi for a common carbon-steel blade.
What causes bandsaw blade drift?
Drift is cause because the blade buckles under the load. You can see that by stretching a ribbon between 2 points and applying a pressure to one of the edges, it will turn sideway easily. A sharp blade and high blade speed will help a lot with that.
How tight should a scroll saw blade be?
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.
What is blade Break?
When you break in a blade, you wear off the sharp pointed edge on the blade teeth and form a small rounded tip. This small radius will be able to better withstand the cutting pressures of sawing and will deliver more consistent cutting results.
When using a band saw how far should the upper blade guides be positioned above the work?
Make sure the blade is positioned properly on the track. Adjust blade guard height to about 3 mm or 1/8 inch to 6mm or 1/4 inch above the top of the material being cut. Wider gaps will place tension on the blade and increase the risk of breaking.
How fast should a sawmill blade run?
Re: Speed of band blade or Rpms Wood Mizer likes the blade to run at 5800 Surface Feet Per Min. The LT70 Super is the first mill for Wood Mizer than you can adjust the band speed through engine RPM. Frozen and extremely hard and dense wood MAY cut better with a slower band speed.
How many teeth per inch should a bandsaw blade have?
The general rule of thumb is: For wood and soft materials aim for 3 – 6 teeth in the workpiece. For metals and harder materials aim for 6 – 24 teeth in the workpiece.