Leave BS in tension or not??

[Alexam]

Those of you with bandsaws - do you leave your bandsaw set up on full tension for the blade, or do you religiously 'slack-off' when your machine is not in use.

Which 'should' you do in the interests of good practice and what are the downfalls, if any, of leaving the tension on the blade?

Alex

 

[pip1954]

hi alex i always leave mine set up just lazy i suppose never nticed any problem
pip

 

[RogerP]

^^^^ same as pip1954.

I've never had a problem, stays cutting straight, never had a breakage and is always ready for use.

Some say continually changing the tension leads to more failures.

 

[RobinBHM]

Narrow blade bandsaws can be left tensioned, certainly the one I have is left under tension and it doesnt seem to suffer. Itll be interesting to see what other people think.

Wide blade bandsaws used for re-sawing are a different kettle of fish. It is vital the blade is untensioned as soon as you finish cutting. But these saws usually tensioned with a hydraulic piston and weights so take seconds to change states.

 

[wizard]

always leave mine set up

 

[AES]

Hi Alex,

When I bought my little bench top BS I knew nothing whatever about them so I then bought Mr. Maskery's 3 x BS DVDs (VERY good investment, usual disclaimers).

Steve clearly says de-tension after every use, and as all the other advice on his DVDs has worked 100+%, I now also de-tension after every use. There's a BUT however - I'm very much a hobbyist and may not use the BS from one week to the next. If I was a "profi" (as we call them here), or even a hobby frequent user, then perhaps I wouldn't be so "pedantic".

To help me remember, I've got a string loop with a placard hanging on the tension knob which says "NO TENSION" on one side and "+ 2 TURNS" on the other. I simply turn the placard round each time I use the BS.

Probably overkill but so far I haven't forgotten.

HTH
Krgds
AES

 

[KevM]

To help me remember, I've got a string loop with a placard hanging on the tension knob which says "NO TENSION" on one side and "+ 2 TURNS" on the other. I simply turn the placard round each time I use the BS.

Tagging out the bandsaw like that is a really good idea; I've only started up once without tensioning - it took me a few seconds to work out why I was hearing all the usual noises but not seeing much action in the blade department.

 

[Steve Maskery]

I think it is a case of do as I say, not as I do. I rarely de-tension but feel I ought.
If I were using the machine every day I would not bother to de-tension, but if, like AES, there are long periods between use, de-tensioning is a good idea, especially on narrow blades like 1/8" or even 1/16th", which can dig into the tyre. I'm not sure how much of a problem blade stretching is, or that of getting a flat spot. I've heard tales of both but never experienced it myself.
I like the big label idea, I've seen it before but it's a good reminder. At the Community Workshop where I hang out we have a similar label for the kiln. Simple and it works.

 

[Giff]

I have a mid-range Axminster bandsaw with a de-tensioning cam type lever. One pull down for on, one push up for off. There must be some thinking or reasoning for putting that on these machines ? Geoff

 

[Alexam]

That's an interesting set of replies. I must admit that I have not de-tensioned, but am reasonably new woodworker and only had this first bandsaw for a few months. Just thought I would ask before I move up to a 16" machine in case I was not being correct, but it sems that if you are using your machine fairly regularly, then leave it set up and ready to go.

I have an outstanding question for Steve Maskery, who had the ingenious idea for blade support of the smaller blades, where the guides may not give enough coverage of the blade. His idea is to use 'backing board' material stuck to the guides with double sided tape and allow the blade teeth to make their own space, which gives more support. What make of tape do you use Steve? I would think it needs to be fairly strong to avoid the boards not being pulled off and it's an idea that I would like to use on a 1/8" blade.

Alex

 

[Steve Maskery]

Hi Alex
Well I'm not sure what make I had when I made the video, but I do have a roll of 3M in front of me and it is probably the same. I don't think the disks experience a lot of stress once they are bedded in, which takes just moments, I guess. Anyway, I have never had a problem with them coming off.
S

 

[Random Orbital Bob]

Alex, the RP BS400 manual does mention its good practice to slacken the tension using the cam lever when not in use to preserve the spring life in the tensioning assembly. Is the manufacturer always right? Dunno but it makes logical sense to me, so I generally do it.

 

[Alexam]

Thanks for the info Steve. I even thought about getting addiional guide blocks just for the narrow blades and swap over for the others, but that may be a bit fiddly.

Hi Rob, I think with the cam leaver, or a similar device, it could be much easier to untighten the blade. Presumably letting off and then putting back on will not need any additional adjustment? Off to Paskins this morning and will check that out with Dave.

Alex

 

[Bluekingfisher]

Personally I never leave mine under tension.

It's one of the checks (that and switching off all plugs) at the end of the day when I leave the shop.

David

 

[custard]

How often do you put your car up on blocks to prevent flat spots on the tyres?

 

[Giff]

You have just reminded me. Off to do the box trailer now ! : ))

 

[paulm]

I have a mid-range Axminster bandsaw with a de-tensioning cam type lever. One pull down for on, one push up for off. There must be some thinking or reasoning for putting that on these machines ? Geoff

Makes it quicker to change a blade and then set back to the same tension (if the same size of blade) ?

I've never left my startrite de-tensioned in the last dozen years or so and never noticed any problems with blades, tyres or spring.

Cheers, Paul

 

[Bluekingfisher]

How often do you put your car up on blocks to prevent flat spots on the tyres?

That's a very personal question, take the day off.

 

[AES]

@custard:

I suspect (can't really prove it) that there's a big difference between the point loading (psi) with a car at rest standing on its tyres and a bandsaw blade pressing against a quite thin single piece of rubber on a pretty small area.

Also, in my case, I'm talking about a real cheapo BS. The "strength" of the the pressed steel casing comes mainly from its shape and its flanges, so I guess it's probably fairly easy to distort over time. Also there's the pressure on the wheel itself, the tensioning mechanism, and the wheel bearings (especially on the upper wheel). Cars are built to stand still (as well as move), cheapo bandsaws may well (rpt MAY, I don't know) be better off if the tension is relaxed when not in use.

Anyway, personally I can't see that de-tensioning does any harm, and it MAY help extend the life of the tool. It's just a question of getting into the habit.

AES

 

[Bluekingfisher]

@custard:

I suspect (can't really prove it) that there's a big difference between the point loading (psi) with a car at rest standing on its tyres and a bandsaw blade pressing against a quite thin single piece of rubber on a pretty small area.

Also, in my case, I'm talking about a real cheapo BS. The "strength" of the the pressed steel casing comes mainly from its shape and its flanges, so I guess it's probably fairly easy to distort over time. Also there's the pressure on the wheel itself, the tensioning mechanism, and the wheel bearings (especially on the upper wheel). Cars are built to stand still (as well as move), cheapo bandsaws may well (rpt MAY, I don't know) be better off if the tension is relaxed when not in use.

Anyway, personally I can't see that de-tensioning does any harm, and it MAY help extend the life of the tool. It's just a question of getting into the habit.

AES

A very valid response AES, however I believe there was more than a hint on sarcasm in the response by custard. :wink: