# Breaking blades



## martinka (15 Apr 2013)

I'm having real difficulty figuring out why I am breaking so many blades. I broke about 10 today so far, all Olson blades. They mostly break in the middle though one did break at the bottom. At this rate I am going to be a nervous wreck as I jump about 3 feet every time I hear the dreaded 'bang!' It got to the point where I daren't use the Hegner so I set the Jet up again on the bench and did the job on that, without breaking one single blade.

I've tried tensioning by feel, and by ear. I've read that people tend to put too much tension on. Well, how much is just enough?

So, people, how do you go about tensioning yours? If you used to break blades when you were new, how did you overcome it? Or did it come with experience?

Martin, very despondent at the moment. But at least my quick clamp is on its way.


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## stevebuk (15 Apr 2013)

you need to pluck the blade and hear a note of about middle C to be tightened about right, i just need to find a music teacher now..


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## Philjohn60 (15 Apr 2013)

Hi Martin - I emailed you earlier to explain that my hard drive gave up the ghost on the Sunday that I collected my saw, so I'm catching up with things and noticed you've been having a few problems with your Hegner. When you were talking about vibration on the other thread, how bad is it? As you know, my saw is on a Hegner stand and to be honest, I don't get any vibration whatsoever. I can stand a penny on edge on the saw's table and going from minimum to maximum speed, the penny doesn't move. I believe your saw is single speed but nevertheless should really perform the same. Do you have a wooden floor? If not and you've got it bolted down, I'm afraid I'd be bit concerned that something was not right. With the blades breaking too, I'm wondering whether one of the arms is out of allignment for some reason. Have you left feedback for it yet? PM me if you prefer.

Cheers

Phil


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## martinka (15 Apr 2013)

Steve, the wife has one of those electronic thingumajigs for tuning her guitar, I'll give it a try. Although I listen to music constantly, I wouldn't know a C from a saw. 

Phil, the garage has a concrete floor and I have a piece of steel, which at a guess weighs about 50lb, on the stand cross pieces. I couldn't get that AND the bag of concrete to fit. 
Removing the 6mm bolts and fitting 8mm ones to bolt it down did help a little. It makes quite a difference if I change it to the shorter stroke, but I doubt I could stand a coin on the table without it walking off. Don't get me wrong, I'm not going to get tingling fingers or anything like that, but sometimes when my hands are on the table, you can hear the ring on my right hand ticking away with the vibration. I've had the arms off to check the bearings and they are fine, and I can't feel any play in the link from the motor. The blade lines up smack in the middle of the slot in the table. Sooo, while it doesn't sound to be as smooth as your own, I'm pretty sure vibration isn't a problem. In fact I'm convinced it's to do with needing to find the correct tension and having the blade straight in the clamps. It takes me a couple of goes to get the blade straight in the top clamp because my very near vision is terrible. If my arms were a yard longer I'd be OK.  I'm hoping the quick clamp will help with that.

Martin.


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## Baldhead (15 Apr 2013)

Hi guys

Don't know if this will help but I have an app on my iPhone called Cleartune, it's a tuner, and very easy to use, perhaps this will help to get the tension right on your scroll saws.

BH


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## martinka (15 Apr 2013)

Baldhead":3i1l74pm said:


> Hi guys
> 
> Don't know if this will help but I have an app on my iPhone called Cleartune, it's a tuner, and very easy to use, perhaps this will help to get the tension right on your scroll saws.
> 
> BH



Sounds like a good idea, ('scuse the pun), but my phone makes and receives calls and does nothing else. Well, probably text messages too but I never used it.

Martin.


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## mac1012 (16 Apr 2013)

Bit baffling really I went through a phase when I first was scroll sawing when blade kept breaking and I realised I was tightening the bottom clamp too much if breakage near the clamp it could be that ? 

If your arms are out of line it could cause problems , but something not right , have a word with tech guys at hegner if still causing problems they really helpful 

also you should have to really push over the lever really hard on the tension , it should be quite firm but not like using a lot of major force 

mark


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## martinka (16 Apr 2013)

mac1012":22kykkm3 said:


> Bit baffling really I went through a phase when I first was scroll sawing when blade kept breaking and I realised I was tightening the bottom clamp too much if breakage near the clamp it could be that ?
> 
> If your arms are out of line it could cause problems , but something not right , have a word with tech guys at hegner if still causing problems they really helpful
> 
> ...


 
Hi Mark, only one blade has broken at the bottom, they nearly always break in or towards the middle. A couple of times I have been cutting as light as possible and still the blade snapped. I'm thinking about what you say about my arms being in line because once or twice I have noticed myself trying to move around the saw. Maybe I should try sitting, although I like to stand because of back problems. Trouble is I jump that much when it breaks that I am likely to end up on my back on the floor. :mrgreen: 

BTW, I am only cutting some crappy 3mm ply, so it's not like I am needing to put a lot of pressure on the blade.
The middle C idea is difficult to use because I am doing all internal cuts. Flick the blade when its in a 1/16" hole and it just clunks.  

Martin.


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## boysie39 (16 Apr 2013)

stevebuk":3fvajmct said:


> you need to pluck the blade and hear a note of about middle C to be tightened about right, i just need to find a music teacher now..



:shock: :shock: After all the strange things and methods I had to learn on the turning section :roll: Here on the scroll saw section I now have to take me saw to a music teacher :shock: :roll: .

So you want to join the music group what instrument do you play .**The Scroll Saw ** enter the men with the white coats ,AGAIN.  :mrgreen: :mrgreen:


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## martinka (16 Apr 2013)

boysie39":buz825xr said:


> stevebuk":buz825xr said:
> 
> 
> > you need to pluck the blade and hear a note of about middle C to be tightened about right, i just need to find a music teacher now..
> ...



Creedence Clearwater Revival - Scrollin' On The River.


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## Ian down london way (16 Apr 2013)

I've been cutting thinish ply for my clock (see WIP  and have to use a thin blade with a high tooth count per um cm. On thin ply, they are fine (using an old henger). When I needed to slice up some 1 inch softwood, the same blades were slow to cut, so one applies more pressure - and the inevitable result is low life for the blade.

So I find, the best thing is to ensure I change the blade to one appropriate for the thickness of the material. The blades with fewer teeth are much stronger, so you can tighten them more, (same middle C), and they last longer. 

I must get my daughter's guitar tuner outside and see what I tune the blades to - as I do it by ear, and also I have no clue what a middle C is.

(You only need a couple of teeth in continuous contact with your wood - I think that's the rule)


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## martinka (16 Apr 2013)

I'm using Olson #3 Double tooth, 23tpi

I just spent ages setting a new blade up, checked it, checked it again, and just to be sure I checked it again. Literally seconds after I started cutting, the blade snapped in two places.


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## Gary Morris (16 Apr 2013)

have you checked that the blade is square all four sides. Are you feeding the wood in at an angle or pushing too hard into the blade? Is there sufficient tension? Is there a min and max tension setting, if so I'd try a blade at Max, half way and finally min, if all three break, it's probably not the tension that's to blame.


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## martinka (16 Apr 2013)

Gary Morris":3v3l5swo said:


> have you checked that the blade is square all four sides. Are you feeding the wood in at an angle or pushing too hard into the blade? Is there sufficient tension? Is there a min and max tension setting, if so I'd try a blade at Max, half way and finally min, if all three break, it's probably not the tension that's to blame.



Hi Gary,

With screw tension, the tension is infinitely variable. On the Hegner, you set the tension with the screwed rod, then you have on and off with the quick tension release lever for changing the blade. At least you do on mine. (Apologies if I am teaching egg sucking here.) BTW, the tension rod had a couple of slight bends which I straightened out, though I doubt very much that it had anything to do with the blade problem.

I am feeding in at an angle sometimes, but then that's when using spiral blades, though with flat blades, I am feeding from the front. The blades have broken at times with little to no pressure, so it's not from pushing too hard. In fact I've got so scared of the damn things breaking, I think I am trying to cut with no pressure at all now. :mrgreen: 

Now the good news. My quick clamp arrived and is fitted. The bad news there is that the revolving part of the clamp still had a pip on from being turned in the lathe and I had to stone it off. Anyway, I changed to a different blade, fitted the quick clamp, and sat, instead of standing, in front of the saw. I've made about 6 internal cuts of the Tribal Kitten pattern with NO breakages! I'm still a nervous wreck, waiting for it to happen, and my shoulders hurt from being so tense, but I think there's light at the end of the tunnel. 

Thanks for all the input. I'm convinced I will get there eventually, it's just so damn frustrating.

Martin.


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## Ian down london way (16 Apr 2013)

Having grabbed my daughter's guitar, I can confirm that middle C is the first note of Frère Jacques


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## MIGNAL (25 Apr 2013)

You can't tension a scroll saw blade (or a Bandsaw blade) to the pitch of a specific note - well you can but you would also have to know the exact type of blade as a reference. You would also have to know the exact distance between the clamping points, that might vary on pinless blades. It's basic Physics. Thinner, shorter blades will reach the pitch at a much lower tension than thicker, slightly longer blades and I strongly suspect that pinned blades will be different from pinless. 
I just don't think it's a good method of determining correct tension.


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## martinka (26 Apr 2013)

MIGNAL":2pjj7ajz said:


> You can't tension a scroll saw blade (or a Bandsaw blade) to the pitch of a specific note - well you can but you would also have to know the exact type of blade as a reference. You would also have to know the exact distance between the clamping points, that might vary on pinless blades. It's basic Physics. Thinner, shorter blades will reach the pitch at a much lower tension than thicker, slightly longer blades and I strongly suspect that pinned blades will be different from pinless.
> I just don't think it's a good method of determining correct tension.



While you are correct, for a number of people it seems to be a good starting point, though maybe not for anyone who is tone deaf. 

Martin.


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## MIGNAL (26 Apr 2013)

Yes but only 3% of scroll saw users are tone death, it rises to 4% for bandsaw users and 98.9% for table saw users. Table saw users just aren't that bright, sad to say. 
More seriously . . . if one of the very experienced users gave a specific gauge/size of blade ( let's say Mr. average scroll saw blade) and the distance between clamping points that would then make determining tension by a specific note a useful method. 
Of course we would have to use 'concert pitch' @ 440 Hz, none of that silly baroque pitch @415 Hz.

The other method that I've heard used for Bandsaws (I don't use Table saws, honest) is to apply just enough tension so that if cuts true and square. Obviously with a scroll saw that really limits it to the blades designed for cutting thicker wood. With 1 inch material it's fairly easy to determine with an engineers square. 
Either that or keep using,trying, experimenting until you get a feel for the correct tension. My money's on the last method!


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## Bryan Bennett (26 Apr 2013)

Hi Martin over the years I have used different blades,only early this year found F/D blades.Thought that I had found the ultimate blade,then I have found P'egas blades ( swiss) and in my opinion are the best blade that I have had the pleasure of using.
The blade is a No 3 R ( Reverse Skip) ref 90.428 priced at £2 71 p a doz plus pp.I have using the blades now for four weeks and they follow the line well and do tight turns,and have done all that I could have asked of a blade.I bought mine from Workshop Heaven who are located at Banbury.

Bryan


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## martinka (26 Apr 2013)

Bryan, I got some Pegas blades with my Jet saw. I think they were left near the saw in the shop by mistake and I forgot to tell them.  I found them to be good blades too but I was expecting them to be expensive so I have been saving them. Going on your price, they are actually cheaper than the standard Olson blades I have been using. 

I bought some of the Olson PGT blades today after reading good things about them, and they ARE expensive at 4 quid for 6, but I wanted to try them out. They are ground carbon steel and they certainly look far superior to the standard ones, looking through a magnifying glass. In fact they look very similar to the Pegas ones. I'm hoping they will cut the old stool tops that I have been unable to touch with anything else so far.

Mignal, I don't know if you typed "tone death" on purpose, but it suits my missus' singing. 

Martin.


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## powertools (26 Apr 2013)

I am very new to scroll sawing and was looking for new blades. I came across the P'egas ones but it said that they were optimized for metal but would cut wood and to be honest that put me off and I got some of the yellow ones from Hobbies and they have transformed my work.
If the P'egas are good on wood I may also give them a try next time.


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## martinka (26 Apr 2013)

powertools":cjbhifvj said:


> I am very new to scroll sawing and was looking for new blades. I came across the P'egas ones but it said that they were optimized for metal but would cut wood and to be honest that put me off and I got some of the yellow ones from Hobbies and they have transformed my work.
> If the P'egas are good on wood I may also give them a try next time.



Pegas make blades for wood or for metal, just make sure you get the right ones. I imagine the ones for metal would be OK for wood, but not so much the other way round, but I don't know for certain.

Martin.

edit: There's a list of Pegas blades here: http://www.classichandtools.com/acatalo ... lades.html UK site too, so you can order from there as well. I'll compare the Pegas and Olson PGT on Sunday if I get chance.


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## martinka (27 Apr 2013)

I just tried Olson #5 reverse skip and Pegas #5 plain on some 1" wood that I am finding very tough to cut, and I couldn't tell the difference between them. Both will cut it, and in experienced hands, probably much faster than I was cutting it. I'll probably go with the Pegas as they are cheaper, though I have still to try FD/Niqua.

Martin.


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## Bryan Bennett (27 Apr 2013)

Hi Martin I have a pattern that I have not cut out yet,Sue Mey the designer has stated to use a No 12 blade to cut out the sides of the box,which will be around the 1 inch to 1 1/2 inch.I bought some from Workshop Heaven No 12 SPR ref 90.444.they were £5.20 a doz plus p&p.It may be a case of a larger blade than a No 5.Sorry but we are in a area that I have not been yet. 

Bryan


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## martinka (27 Apr 2013)

Hi Bryan, you're spot on. I found a larger blade, the one that was actually in the Jet when I bought it, so I popped it in the Hegner and it easily cut the wood I'd had trouble with. I think the answer was having a blade big enough that I wasn't scared to put some pressure behind the wood.

Martin.


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## mac1012 (28 Apr 2013)

pegas blades sound interesting I usually use niqua I have tried the olsen blades the diamond ground ones are the dogs cahoneys but a tad expensive for me the normal olsen ones I find quite good too.

I ready for some new ones so I going to order some 

as a rule of thumb you should use the smallest blade to get the finished required so you step up in size the thicker the wood right ? well yes and no if you haven't any tight turns in say 1" and half wood thickness then skys the limit but if you have then a thicker stronger blade is not going to get in as tight so it a matter of finding a happy medium by not going bigger than you need.

the dark arts of tensioning mmmm #-o 

I think you can probably over think things some times as the old saying goes it not rocket science (not quite ) if the cut drifting and blade moving a lot when pressure applied to wood then..... more tension ! 

I put as much on as I can get away with I know by the feel of the tensioning lever when pushing it down its just practise really I never pluck for the sound like I said put some on if looks like blade moving a lot put some more on blade usually has about 1mm approx. side movement on correct tension.

mark


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## martinka (28 Apr 2013)

mac1012":2gyzgzgo said:


> if looks like blade moving a lot put some more on blade usually has about 1mm approx. side movement on correct tension.
> 
> mark



Trouble is, that 1mm is rather like the middle C; how do you achieve that figure? How much back to front, or side to side, pressure do you apply to make the blade move 1mm? A little bit, a lot, or a middling amount? :mrgreen: As you have pointed out, the only real way to find the correct tension is by experience. Of course, the 1mm and middle C are good starting points.


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## mac1012 (29 Apr 2013)

I never really put that much thinking time into blade tension to be honest.

I not knocking the middle c club its just something I have never done, the way your work cuts will tell you all you need to know about blade tensioning.

mark


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## martinka (29 Apr 2013)

mac1012":3qf732uf said:


> I never really put that much thinking time into blade tension to be honest.
> 
> I not knocking the middle c club its just something I have never done, the way your work cuts will tell you all you need to know about blade tensioning.
> 
> mark


I'm in complete agreement, Mark. Although your work probably won't tell you until you have had a lot of experience, then eventually it will (hopefully) become second nature. 

Martin.


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