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.
Bandsaw tensioning After I built my home made bandsaw, I wanted to get a better idea of how much tension I was putting on the blade. “Bandsaw blades can take 15,000 PSI of tension. A greater limit is how much force your bandsaw can take. From my measurements, given the limitations of a typical bandsaw, it’s just about impossible to over-tension any but the narrowest of bandsaw blades. 70 pounds is more than my 14” bandsaw is capable of. Home made tension gauge Because clamping a caliper to a bandsaw blade is awkward and can damage the blade, I built myself a simple bandsaw tension gauge using some birch plywood and a dial indicator.
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.
We’ve seen various methods for setting bandsaw blade tension, from fancy gauges to plucking the blade like a guitar string. Turn the tensioning handwheel until the tension gauge is at or a little above the recommended tension for your blade width. With the saw running, slowly release the tension-about 1⁄2 turn of the tensioning wheel at a time-until the blade starts to flutter, as shown at right.
bandsaw blade tension formula Related Question:
How much tension should a bandsaw 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.
What is tension gauge?
Push & Pull Tension Gauge This is a multi-purpose dynamometer to measure compression and the competence tension of the measured object by using a head or hook.
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 much tension should a hacksaw have?
I would endorse the ‘finger tight plus three turns’ recommendation. It is important that the blade is taut. Also the angle of the saw when cutting is important, always use it by sloping the front end downwards, away from you, never upwards.
Why do bandsaws wander?
If the wheels are worn and do not have a distinct top to the crown then the blade will not know where to go, and may wander around. This of course can cause poor cut quality and difficulty in setting the guides.
Why does my bandsaw blade wobble?
The blade on a saw left idle for long periods of time can leave an impression in the rubber tire which might cause erratic tracking. Purchase and install aftermarket replacement tires. (Search for “bandsaw tire” at woodcraft.com.) If you still see a back-and-forth motion, the culprit is probably the wheel itself.
Why can’t I cut a straight line with my bandsaw?
Band Saw: Why won’t my band saw cut straight? When the band saw cuts crooked, a dull blade, improper feeding, loose blade tension or not using a work piece guide could be the cause. Use the rip fence or miter gauge to guide the work piece uniformly through the cutting blade to make straight cuts.