Bandsaw Blade Tension

[CommGuy107]

So I installed a new blade on my Rikon 10-325 today, and the tension was all whacked out. I used the handy "numbers in the window" method, and double checked to make sure I didn't leave some important step out (not my first bandsaw), but it was wa-a-a-ay too slack at the mark for a 3/16" blade.

I dialed it all the out to the 5/8" blade setting for proper tension and adjusted all the guides and it cut like a champ. Suppose Klingspor's had an improperly labeled blade?

 

[chris_goris]

Doubtful about the improperly labeled blade… those indicator arrows on bandsaws are never accurate, they are based on spring compressions that can vary widely. Tension it to where you think it feels right, but pay special attention to the small blades that they are not embedding into your tires.

 

[ehpoole]

The indicators on Rikon's bandsaws are actually pretty good ballpark figures to get you in the proper vicinity. However, like any indicator that indicates based upon tensioning spring travel it is only accurate if the blade is of the proper length for the bandsaw. Some blade manufacturers, such as Olsen, sell blades that are up to 1/2" to 1" longer than stated on the package, which can really throw the indicator's usefulness out the window. However, you can still use the indicator in the future once you have learned what constitutes an appropriate level of tension for a specific blade. In fact, on my older Rikon 10-345 I had to adjust the tension limiter stop to allow enough vertical travel to accept and properly tension Olsen brand blades due to their added length (when I tension my 1/4" Olsen blade the tension gauge will read well in excess of 1-1/4", whereas my other blades, mostly Timberwolfe, are nearly always within about a needle, or twos, width of the indicated position for that width blade).

That said, until you learn the proper indication for a new blade, it is best to use the deflection method, coupled with feedback while making test cuts, to determine the proper tensioning level for your new blade. Done this way you are unlikely to go wrong. Just avoid excessively over tensioning a blade unless you really need that added tension for a job, then always release the tension when finished (or at least most of the tension, it is fine for some light tension to remain just to keep the blade snug).

 

[CommGuy107]

That said, until you learn the proper indication for a new blade, it is best to use the deflection method, coupled with feedback while making test cuts, to determine the proper tensioning level for your new blade. Done this way you are unlikely to go wrong. Just avoid excessively over tensioning a blade unless you really need that added tension for a job, then always release the tension when finished (or at least most of the tension, it is fine for some light tension to remain just to keep the blade snug).

Thanks for the useful info and reminders. Appreciate the time and thought you put into replying. ~Dan

 

[Endless Pursuit]

What is the "deflection method"?

Same this as "flutter method"?

 

[CommGuy107]

What is the "deflection method"?

Here's a simple deflection method: Raise the guides about 6 in. off the table and push the blade. The blade should deflect no more than 1/4 in.

 

[Hmerkle]

Here's a simple deflection method: Raise the guides about 6 in. off the table and push the blade. The blade should deflect no more than 1/4 in.

I resisted responding but have this question; Isn't that dependent on the blade thickness? (thickness not width [3/16,1/4, etc.])
As Ethan said the indicator is usually pretty good unless the blade length is off... Mark Duginski said that exact thing!
I thought the flutter method was on used on Timber wolf blades?

 

[nn4jw]

I use a shop-built tensioning gauge as shown in this video:

https://www.youtube.com/watch?v=9iAkRLvLAvI


Works great and was easy to make.

 

[Hmerkle]

I use a shop-built tensioning gauge as shown in this video:

https://www.youtube.com/watch?v=9iAkRLvLAvI


Works great and was easy to make.

Thanks Jim, GREAT DIY tip!

 

[Joe Scharle]

I let it pop off my finger like a harp string. Looking for a middle G.
Unless I'm in a classical mood; then I'm looking for a Am7!

 

[Hmerkle]

I let it pop off my finger like a harp string. Looking for a middle G.
Unless I'm in a classical mood; then I'm looking for a Am7!

We call him "perfect pitch Scharle"

 

[ehpoole]

I resisted responding but have this question; Isn't that dependent on the blade thickness? (thickness not width [3/16,1/4, etc.])
As Ethan said the indicator is usually pretty good unless the blade length is off... Mark Duginski said that exact thing!
I thought the flutter method was on used on Timber wolf blades?

One may use whatever method works for them, what's important is to learn at least one method.

The deflection method is one of the simplest to convey and is quite reliable in my experience. The thickness of the blade has a great bearing in blade performance and total tensioning required, especially when resawing, but you are still looking for a similar level of deflection regardless of the blade you are using, though the gap that you test for deflection should be reduced as the blade gets narrower (as one does not typically use a 1/8" blade for a 6" or 12" deep cut). Any how, you will quickly refine this method once you begin sawing and resawing and learn from actual feedback whether or not you need more or less tension for each task. These days I usually just test for deflection over the full 12" (or with guides fully backed off) and gauge from that whether I have an appropriate amount of tension for the blade and task, and you will likely develop that sense as well if you use and develop the same technique.

I will also use the method of plucking a blade and listening for a tone, which is another good way to determine if you are at least in the right ballpark provided you have a sufficiently quiet shop as the frequency and sound level can be quite low on large blades installed on the larger bandsaws. With this method you are in the vicinity of the right tension when you have achieved a clear crisp tone upon plucking the (backside) of the blade. Too little tension and the sound will be very muddy. It is usually easier to pluck the backside of the blade (from upper or lower wheel house) as the frontside may interact with the guide rollers and ruin the effect.

With any method, it is important to properly setup the guides, both height above your work and a proper guide gap between guides and blade so that they do not actually contact a free spinning blade (but are just a hair shy of contact), once you have dialed in your starting tension so that they can properly support the blade, especially when resawing where there can be a lot of stresses working on the blade and trying to take it off course.

 

[zzdodge]

I let it pop off my finger like a harp string. Looking for a middle G.
Unless I'm in a classical mood; then I'm looking for a Am7!

Exactly. +1 for Joe