Hegner blade breakage question.

[jbrowning]

Hello everyone, so I've been using the Pegas Modified Geometry blade #3 and broke one yesterday and then 2 more tonight (within a 2 hour period tonight). They have all broken about 1"-1.5" above the lower blade clamp holder. Do you think that is because I'm making too tight of a cut and pushing the blade too hard or maybe something is out of wack? This is on my Hegner 18V Scroll Saw.

Thank you

Jim

[OCtoolguy]

22 minutes ago, jbrowning said:

Hello everyone, so I've been using the Pegas Modified Geometry blade #3 and broke one yesterday and then 2 more tonight (within a 2 hour period tonight). They have all broken about 1"-1.5" above the lower blade clamp holder. Do you think that is because I'm making too tight of a cut and pushing the blade too hard or maybe something is out of wack? This is on my Hegner 18V Scroll Saw.

Thank you

Jim

I have had a couple break at about the place. I'm using my Ex 21 and cutting some intricate fretwork in 2 1/4" thickness hickory using #3 mgt. Making a lot of sharp turns and I think they just get tired of the twisting and break. 

[Wichman]

41 minutes ago, OCtoolguy said:

I'm using my Ex 21 and cutting some intricate fretwork in 2 1/4" thickness hickory using #3 mgt

I read that as (1) piece, 2 1/4" thick. Did you mean (2) 1/4" pieces?

 

[Wichman]

On my Hegner, at the top of the stroke, the point of contact with the  bottom of the wood is about 1 inch above the bottom clamp. It would make sense for blades to commonly break there, heat and stress would be highest at that point.

[stoney]

First I would try a little more tension. Second try a different brand blade.  Third I would try adjusting saw speed and feed rate.  One thing I have found in 13 years of using my Hegner is once you find the tension sweet spot you stop most of the blade breakage

[OCtoolguy]

13 hours ago, Wichman said:

I read that as (1) piece, 2 1/4" thick. Did you mean (2) 1/4" pieces?

 

Yes. Thanks Wick.

[Scrappile]

I break more Pegas blades than FD. But they seem to break at the time I am thinking I need to change the blade because I am having a harder time controlling it do to wear..  Seems to me have a tendency to snap when worn, where as other blades do not... May just be my imagination.  Never worried about it, I get my use out of them... 

[OCtoolguy]

7 minutes ago, Scrappile said:

I break more Pegas blades than FD. But they seem to break at the time I am thinking I need to change the blade because I am having a harder time controlling it do to wear..  Seems to me have a tendency to snap when worn, where as other blades do not... May just be my imagination.  Never worried about it, I get my use out of them... 

I agree Paul. I think the Pegas blades may be a bit harder and may snap a bit quicker than other brands.

[rash_powder]

I have been suffering a lot of blade breakage lately on my Hegner also.  Most seem about 1/8" below the top clamp, the bulk of the rest about 1 1/4" up from the bottom clamp.  Upon reviewing the manual I found that I was over-tensioning the blades - Hegner says no more than 1 turn of the tensioner from no slack and I was going 1 1/2 or more.  Less tension has helped some, but I fear my current favorite blade has gone down in quality too, though I can't say for certain as I don't date the bundles of blades I have.  I do tend to push the cutting life too as they feel sharp even when broken.  

Struggling is my thing, as is over thinking which is where I am at with it now.  I'm trying to work out how to set the tension to approx 15000 psi as that is give or take where a bandsaw runs and a scroll saw blade is in a very similar situation.  

I tried tunining to 'C', but all the guitar tuning apps show it going from B flat straight to D sharp so that idea is a no go.  

If I ever figure something sciency and repeatable and measureable out I will post.  I'm not too keen on the do it by feel thing.  

[OCtoolguy]

2 hours ago, rash_powder said:

I have been suffering a lot of blade breakage lately on my Hegner also.  Most seem about 1/8" below the top clamp, the bulk of the rest about 1 1/4" up from the bottom clamp.  Upon reviewing the manual I found that I was over-tensioning the blades - Hegner says no more than 1 turn of the tensioner from no slack and I was going 1 1/2 or more.  Less tension has helped some, but I fear my current favorite blade has gone down in quality too, though I can't say for certain as I don't date the bundles of blades I have.  I do tend to push the cutting life too as they feel sharp even when broken.  

Struggling is my thing, as is over thinking which is where I am at with it now.  I'm trying to work out how to set the tension to approx 15000 psi as that is give or take where a bandsaw runs and a scroll saw blade is in a very similar situation.  

I tried tunining to 'C', but all the guitar tuning apps show it going from B flat straight to D sharp so that idea is a no go.  

If I ever figure something sciency and repeatable and measureable out I will post.  I'm not too keen on the do it by feel thing.  

Me thinks you are "over-thinking" the issue. I just tension til it feels right. Pluck the blade and it's either "plunk" or "pling".

Edited November 19, 2021 by OCtoolguy

[rash_powder]

5 hours ago, OCtoolguy said:

Me thinks you are "over-thinking" the issue. I just tension til it feels right. Pluck the blade and it's either "plunk" or "pling".

Oh I know I am.  Just gotta do it though.