Bandsaw Tension

[FMC1959]

I have a Laguna 16 bandsaw. I know that after use, the tension should be loosened. Unfortunately, the mind is not always there and I sometimes forget. Case in point, yesterday I went to use it; first time in about 8-9 months, it was still tensioned. It is a 1" blade, which definitely makes it a bit tougher, but still worried about what can happen when the blade is not slackened after use.

Anyone have experience of either problems that arise from not slackening the blade, or is it a case of "I have never slackened the tension and it has been going for years".

Is the issue more the blade stretches and weakens or is the issue the tension puts strain on the 2 blade wheels which can mess up the bearings?

 

[American Locomotive]

..you're supposed to release the tension after use? I've used a lot of different band saws (portable, wood, metal, horizontal, vertical, small, large) in a lot of different settings (residential, commercial, industrial) and I can't recall ever loosening the tension, or coming across the saw with the tension released from someone else's prior use.

I've also never have seen that mentioned in any saw's user manual or operating instructions attached to the saw.

 

[RoninB4]

35 years in machine shops having band-saws, usually more than one. Never taken the tension off any after use, nor have I seen anyone do this. Tension was removed ONLY when replacing the blade. Do guitar players take the tension off strings after each use? Perhaps a good idea for both but I fail to see any advantage.

 

[PBCampbell]

It's probably more likely to do damage to the machine. ALWAYS release tension on equipment that sees sporadic use and it's probably wise to release tension after use even if it will be used daily. This applies to hacksaws, coping saws, etc. as well.

 

[FMC1959]

35 years in machine shops having band-saws, usually more than one. Never taken the tension off any after use, nor have I seen anyone do this. Tension was removed ONLY when replacing the blade. Do guitar players take the tension off strings after each use? Perhaps a good idea for both but I fail to see any advantage.

This goes back many years; I can't recall where I first heard about this but 40 years ago, or so, I had bout a small Shopcraft bandsaw and it had a lever on the side. Just flick the lever and it was tight, then the other way and it was loose. It also specified in the instructions to release when not in use.

Then when I bought my Laguna, 2nd hand, the guy told me he would put a block of wood on the table and had written "TENSION" in big letters on the block to remember before turning it on to tighten it up.

Anyway, if both of you and others also reply they don't or never new they had to, it looks like it might be a very low risk problem leaving it always tensioned

 

[Kuma601]

Having it tensioned up does promote stretch and may compress the wheel rubber. I use it fairly regularly that doing the tension routine becomes a pita. Various articles about QR type bandsaw tensioners. In my practice only time I take tension off the bandsaw blade is to change it. If it sits I'll spin it to allow the band tension to sit at a different location on the wheels.

I will take tension off the belt sander belts because they tend to stretch and place additional stress on the **** joint splice. Had one hacksaw tensioned up and it eventually split the frame so now when done the blade is removed.

 

[FMC1959]

It's probably more likely to do damage to the machine. ALWAYS release tension on equipment that sees sporadic use and it's probably wise to release tension after use even if it will be used daily. This applies to hacksaws, coping saws, etc. as well.

See, the latter part of your statement..."hacksaws, coping saws, etc. as well"... tells me that as a Best Practice this should be done. But I have never known anyone that does this to coping, hacksaws and the like.

This isn't to say like, phew, loosening my bandsaw blade is not necessary, but if I forget, it is not the worst thing. Plus, on my Laguna, it isn't a simple lever that takes all of 2 seconds like on my very small Shopcraft. You have to rotate a metal knob on the inside top cover, and it is pretty stiff, and requires a few turns.

Not the end of the world but still a bit of a PIA to do before and after every use.

 

[FMC1959]

Having it tensioned up does promote stretch and may compress the wheel rubber. I use it fairly regularly that doing the tension routine becomes a pita. Various articles about QR type bandsaw tensioners. In my practice only time I take tension off the bandsaw blade is to change it. If it sits I'll spin it to allow the band tension to sit at a different location on the wheels.

I will take tension off the belt sander belts because they tend to stretch and place additional stress on the **** joint splice. Had one hacksaw tensioned up and it eventually split the frame so now when done the blade is removed.

Like you said about blade stretch and compressing the rubber, I am sure that the MFR's say to release tension for a reason. Of course, if they were many cases of blades breaking and causing hazardous injury. Or in the other instance, many people complaining about the cost of repairing bushings, bearing and other parts, then I believe more people would do it.

As it is, with few or no instances of things going bad, I guess people don't slacken it because it is a PIA.

 

[Kuma601]

Those Lagunas are nice saws. For a fine woodcrafter the subtle tuning may be worthwhile to optimize blade performance when cutting $$ wood.

I wouldn't mind one simply from a blade changing aspect. Cranking 20-30 turns on a progressive spring to tension up or detension a blade makes my hands hurt. My hands hurt each day from the accumulated years of doing the physical tasks. I would definitely suggest this from that standpoint alone.

 

[mike93lx]

No one does that

 

[RTM]

I have a Laguna 14SE, and I always loosen the blade so I don’t compress the rubber tires irregularly. When one is trying to resaw wood into thin layers like veneer or instrument back, the thumping from out of round (flat spotted) wheels will put an oscillation in the blade, resulting in an uneven cut, wasting wood, or requiring more clean up work to straighten out. In resawing, you are taking up to say a 12” tall piece of 2” wide wood, and trying to slice it down into 1/16” or 1/8” thick slices.

I’m am not worried about damaging the blade into breaking, though they may also take a set in thicker blades, adding to the oscillation.

And you do want high tension when you are cutting, else the blade can wander in the cut.

 

[isb cornbinder]

I have a Laguna 16 bandsaw. I know that after use, the tension should be loosened. Unfortunately, the mind is not always there and I sometimes forget. Case in point, yesterday I went to use it; first time in about 8-9 months, it was still tensioned. It is a 1" blade, which definitely makes it a bit tougher, but still worried about what can happen when the blade is not slackened after use.

Anyone have experience of either problems that arise from not slackening the blade, or is it a case of "I have never slackened the tension and it has been going for years".

Is the issue more the blade stretches and weakens or is the issue the tension puts strain on the 2 blade wheels which can mess up the bearings?

The blade takes a set pattern. It should be run for a minute before loading it up. I am from the school of "I have never slackened - - - - - - - ."

 

[darkzero]

I've heard this too but I have never met any that does release tension when not in use. I had a 4x6 & currently a 7x12 but they are just hobby size bandsaws with no rubber tires. I've never released blade tension, I've never noticed any ill effects. There's times of the year where I may not use it for weeks or months.

 

[RoninB4]

I suppose I should qualify my earlier post in saying that the bandsaws I used were all for cutting metal, many of them having no rubber tires. I can see where having a flat spot on a rubber tire could cause problems in re-sawing expensive wood. If I had an occasional use for re-sawing expensive wood I'd likely release the tension after use as well. If it's just a twist knob an offset crank should be made to make this less of a PITA.

RTM- Nice piece

 

[dnschmidt]

I have that exact Miber (that's who actually made that bandsaw) bandsaw and I do release tension but I wouldn't be too worried if I forgot to. Most people don't tension band saw blades nearly enough. If you look up the specifications these things are suppose to be tensioned like guitar strings. Under tension is a far more common problem than over tension.

 

[Gizmosity]

Never ever released tension on older saws for 30 years. That said, the old Delta 14" tension springs were sort of notoriously compressing over years of constant tension. So much so that at least one business sprang up providing aftermarket/stiffer replacement springs.

I have a newer 20" Powermatic saw in my lab and a 17" Grizzly in my shop, both with tension levers to make it fast and easy to release and apply tension to a blade. I suggest ALWAYS spinning the wheels by hand after applying tension to make sure the blade is tracking correctly as I have discovered 'the hard way' that they don't always.

I have a 36" saw at home that used to come with a rubber donut tension devise (made in 1900-ish) that I replaced with a pretty high tension die spring because it was destroyed when I bought it. I've not released the tension on that saw for about 3 years. I highly doubt anyone else did either during it's entire life but I'm sure the tires have been replaced at least once and I did have to replace the donut when it was only 115 years old or so.

And, if you forget you took the tension off, you turn the saw on with no tension and you get it hear it grinding against the door, cutting the tires, etc. In fact, we've had to replace the tires on the saw at school not because of constant tension, but because of being destroyed from students turning on the saw without making sure it was tensioned. A note on the door helps to remind them.
I resaw with a 1" carbide tipped blade and over the last year have never released the tension with zero ill effects. I don't plan on releasing tension this year either.

I am of the opinion that it's a bunch of hooey. Now if you'll excuse me, there's kids on my lawn.....

 

[FMC1959]

Those Lagunas are nice saws. For a fine woodcrafter the subtle tuning may be worthwhile to optimize blade performance when cutting $$ wood.

I wouldn't mind one simply from a blade changing aspect. Cranking 20-30 turns on a progressive spring to tension up or detension a blade makes my hands hurt. My hands hurt each day from the accumulated years of doing the physical tasks. I would definitely suggest this from that standpoint alone.

My Laguna is similar to yours in that it takes 20+ turns and it isn't easily turned...my arthritis doesn't help either.

Gizmosity mentions that his 20" Powermatic saw and 17" Grizzly saw both have tension levers. If there was a simple retrofit to add a lever system, that would be awesome...for the hands anyway, remembering to do it is another matter.

**** Gizmosity, did you get the no good, dirty rotten kids on your lawn?

 

[Gizmosity]

My Laguna is similar to yours in that it takes 20+ turns and it isn't easily turned...my arthritis doesn't help either.

Gizmosity mentions that his 20" Powermatic saw and 17" Grizzly saw both have tension levers. If there was a simple retrofit to add a lever system, that would be awesome...for the hands anyway, remembering to do it is another matter.

**** Gizmosity, did you get the no good, dirty rotten kids on your lawn

My Laguna is similar to yours in that it takes 20+ turns and it isn't easily turned...my arthritis doesn't help either.

Gizmosity mentions that his 20" Powermatic saw and 17" Grizzly saw both have tension levers. If there was a simple retrofit to add a lever system, that would be awesome...for the hands anyway, remembering to do it is another matter.

**** Gizmosity, did you get the no good, dirty rotten kids on your lawn?

Carter makes one for delta/jet 14" saws.
My lawn is over run with moles and deer but kid free.

 

[matt_i]

I feel like its something carried over from the days when rubber was just being developed out of a gum tree but wasn't structurally up to keeping the saw tension for long periods. Or maybe from lead-poured babbit bearings which crept under load, I am not sure but I feel like its related to long-ago resolved materials-science issues.

As others have stated I only mess with tension when changing a blade or the blade is clearly slipping from someone else making a change but not tensioning it adequately.

 

[neophyte]

Compression issues on rubber belts etc, are more likely issues than tension on the steel parts over time.
Belts will get permanent kinks or bends, which will cause vibration issues, which will affect cutting performance, and create extra noise.
The rubber wheel tires can get deformed, which will also cause vibration, but which can also cause extra blade movement that can hinder clean cuts when resawing etc.
while there may be modern ways and naterials that can alleviate or prevent these issues, there is no guarantee that the modern materials where used in any bandsaw.

As far as old babbit bearings go, this could definitely be an issue, since prolonged tension could prevent old glow, possibly leaving babbit under pressure against steel without lubrication.
Metals when compressed together can sometimes start “sticking” to each other.
I don’t think Laguna bandsaws would have this issue though.

 

[bubinga]

Like you said about blade stretch and compressing the rubber, I am sure that the MFR's say to release tension for a reason. Of course, if they were many cases of blades breaking and causing hazardous injury. Or in the other instance, many people complaining about the cost of repairing bushings, bearing and other parts, then I believe more people would do it.

As it is, with few or no instances of things going bad, I guess people don't slacken it because it is a PIA.

FWI's W, l de-tension mine. l wrote on the table with a sharpie + 6 turns, - 6 turns, l usually remember.

 

[bubinga]

No one does that

l do.

 

[bubinga]

I have a Laguna 14SE, and I always loosen the blade so I don’t compress the rubber tires irregularly. When one is trying to resaw wood into thin layers like veneer or instrument back, the thumping from out of round (flat spotted) wheels will put an oscillation in the blade, resulting in an uneven cut, wasting wood, or requiring more clean up work to straighten out. In resawing, you are taking up to say a 12” tall piece of 2” wide wood, and trying to slice it down into 1/16” or 1/8” thick slices.

I’m am not worried about damaging the blade into breaking, though they may also take a set in thicker blades, adding to the oscillation.

And you do want high tension when you are cutting, else the blade can wander in the cut.

Same with a Hacksaw.

 

[bubinga]

The blade takes a set pattern. It should be run for a minute before loading it up. I am from the school of "I have never slackened - - - - - - - ."

HEEEEY! Bring my bandsaw back! LOL 1966

 

[bubinga]

I suppose I should qualify my earlier post in saying that the bandsaws I used were all for cutting metal, many of them having no rubber tires. I can see where having a flat spot on a rubber tire could cause problems in re-sawing expensive wood. If I had an occasional use for re-sawing expensive wood I'd likely release the tension after use as well. If it's just a twist knob an offset crank should be made to make this less of a PITA.

RTM- Nice piece

That book-matched walnut is beautiful!!

 

[mike93lx]

l do.

There are exceptions to everything.

Practically no one does it

 

[paulsomlo]

I slack off the tension when not in use and open the upper door, as a reminder that it's not tensioned. This is on an MM16, where the tension wheel is on the outside, just below the upper housing - it only takes one turn to slack it off.

 

[dr_clyde]

Not only have I never heard of anyone doing this, I actively would avoid it.

Time is money and I'm not interested in standing at the bandsaw cranking tools to tighten up and then loosen the blade every day.

I've not once noticed a single detriment to having my bandsaws kept under tension. I suspect the tires on my 1960's DoAll are original, and they are in no way compromised by leaving the blade tensioned. Smooth running and no weird vibrations, and that saw sometimes will sit for a few weeks in between uses.

I'm in the camp of "this is a giant waste of time".

 

[2oolhound]

I don't have experience with 14"+ bandsaws but my porter cable 42" blade had a tension lever I always try to disengage after use. My 52" blade metal saw has a light unibody frame you can feel tension when you tighten the blade so I always slack it off after use because I don't want it to get a permanent curve (warp). My 62" 4x6 metal saw I also back off the tension on after use just because I do it with my other saws.

 

[The Cobbler]

never even considered slacking the tension on my bandsaws, it makes sense, but I would never remember to do it , and when I wake up in the morning, I won't even remember reading this thread.

 

[slowtwitch73]

You guys are slackers.

 

[slowtwitch73]

Been messing around with my Doall and using a blade tension meter for the first time, and recommended tension is way tighter than I have ever done it.

I also came across an old Doall blade box that stated that blades stretch, and to release tension when saw is not in use (no reason given). Fwiw.