De-tension bandsaw blades when not in use?

[mattbyington]

Hey team,

I started a thread about an N4400 I bought recently. The blade came yesterday. I'm so, so excited to use it this weekend.

A very basic question and apologies in advance. I have never owned a bandsaw before.

Should I be de-tensioning the blade after working, or leave it tensioned 100% of the time?

Thanks so much in advance.

Matt

 

[Bob D.]

I always do with mine. And to remind myself I have a caution sign on the BS next to the power switch to check blade tension before use.

I printed this out on some bright yellow paper and glued it to one of those fridge magnets you get in junk mail sometimes.

 

[rmhinden]

I have a Delta 14" bandsaw with extension.  I do not de-tension the blades, except with I am changing the blades. 

Doesn't seem to have harmed it in the 25 years I have owned it

Bob

 

[ben_r_]

N4400 owner here and I ALWAYS de-tension any blade I have on my bandsaw even if its only going to be sitting over night. Its just not that hard to re-tension it the next day and why risk blade deformation?

 

[Mike Goetzke]

I de-tension mine - I thought it was more to prevent the tires from deforming than anything else.

Mike

( Edited - when I de-tension I usually don't loosen it all the way because some blades come close to falling off the wheels if you do. )

Found this on Suffolk Machinery web page (lots of other info there too-https://www.suffolkmachinery.com/six-rules-of-sawing.html ):

ALWAYS DETENSION YOUR BANDS
When you are done cutting for the day, take the tension off your blade. Band saw blades, when warmed up from cutting, always stretch; and upon cooling shrink by tens of thousandths of an inch each cooling period. Therefore, blades, when left on the saw over tension themselves and leave the memory of the two wheels in the steel of the band, which will cause cracking in the gullet. When you leave the band on your saw under tension, not only do you distort the crown and flatten out the tires (which makes them very hard), but you also place undue stress on your bearings and shafts. Believe it or not; you can, and will damage your wheel geometry sooner or later and considerably shorten bearing life. You are also crushing your tires or V-belts.

 

[Jiggy Joiner]

It’s good practice to slacken the blade after use. It’s usually just the turn of a lever, and sometimes lock.
I made warning stickers for our bandsaws, they are stuck near the on off switches.
Not slackening the blade will cause stretching, and depending on how temps change, can be quite drastic and cause tyre issues. Stretching causes premature wear too.

Definitely slacken it of when not in use, at least at the end of each day.

 

[WarnerConstCo.]

Never.

Sent from my SM-N960U using Tapatalk

 

[kevinculle]

14" Delta with riser block...I leave my saw blade tensioned with no apparent ill effects.

 

[derekcohen]

Matt, many will say that they do not de-tension, but I always do so. My concern is not so much the blade stretching and fatiguing, but the compression of the tyre. The 1" carbide CT requires the highest down force from the N4400.

Regards from Perth

Derek

 

[vkumar]

The only thing is that you absolutely have to remember to tension it before you turn it on.  If you dont  you might end up trashing your blade, tires etc.

 

[Cheese]

Ya, this is one of those Chevy vs Ford debates.

I purchased a new 8-speed 14" Delta band saw for cutting metal and wood in 1994. The tension with a 1/2" wide blade has never been released since I purchased it.

The original tires are still good, the bearings are fine and it cuts straight.

I've revisited the idea of retrofitting a de-tension arm on the saw many times. Not because I've had issues with the cutting but rather because it makes changing the blade a lot easier.

Don't know Matt...this is a toss-up.

 

[tjbnwi]

Don’t install the blade—problem solved [big grin]

I don’t detension the blade on my Rikon.

Tom

 

[ChuckM]

The newer ones are easy to detension (and tension) and it just takes a second or two. Mine has a threaded rod to unwind...and still, I detension mine everytime after each use.

 

[chewy]

I've never detensioned mine. Sounds like an accident waiting to happen!

Sent from my SM-G960F using Tapatalk

 

[Bob D.]

The only thing is that you absolutely have to remember to tension it before you turn it on.  If you dont  you might end up trashing your blade, tires etc.

Oh, believe me, YOU WILL trash them.

Don't ask.. :-(

 

[junk731]

A total and complete waste of time that can be extremely dangerous. I've run my Felder FB600 since new in 2011, through 10's of thousands of lineal feet of cutting with a Woodmaster CT and never released the tension and had no ill effects that these types of discussions generate. The CT takes an extreme amount of tension that the N4400 can't really achieve to the max potential out of the blade. You have to run it with the spring completely compressed to get any where whats needed and its a complete PIA to tension and detension. This type of info is continually repeated and based low end bandsaw with crap construction and soft rubber wheels not something you find in higher end machines like the Hammer N4400. But as always believe and do as you want it will not make any difference to me.

 

[ChuckM]

Haha. This sounds like the plugged version of "Tails first or pins first" debate.

I think the older, smaller bandsaws and the width of the blade (e.g.,1/8") should be treated differently. Newer bandsaws I have looked into do come with user-friendly detensioners.

It is true that forgetting to tension the blade before turning on the machine could lead to blade damage if the situation is not corrected soon enough. But detensioning is not necessarily the same as loosening. My solution is to leave a block of wood in front of the blade marked in color: "Tension." So far, it has worked...for over 20 years. Others have put their reminders on the power switch like this:https://www.pinterest.ca/pin/683702787154890818/

If in doubt, I would check with the manufacturer whether or not the new saw needs detensioning.

 

[grbmds]

I don't detention and haven't seen any problems develop over time on my bandsaw. I now own a Rikon 10-325 and, over the 5+ years I've owned it I have not had any problems that I can associate with not detensioning.

Some articles I've read say that, if the saw is used everyday, detensioning is probably not a significant issue. If it's not used everyday, the articles say, possible flat spots can develop and extra stress is placed the blade. I think the danger from forgetting to tension the blade again when using the saw is a bigger issue. I have never noticed the saw running rougher because of flat spots and I've never had a blade fail.

 

[junk731]

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. An 1/4" blade on this saw is no different because of the rubber hardness and the fact it really doesn't deflect like an old 14" Delta would. You will get more damage from the teeth cutting the rubber, tensioning has nothing to due with this. 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.

 

[ChuckM]

Every bandsaw manufacture that supplies to a potential hobbyist buyer will put the disclaimer in to detension to cover their butt.

Could they tell if something goes wrong with the machine under warranty whether the problem is due to not detensioning?