Author Topic: Need Advice.  (Read 484 times)

Offline tgbto

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Re: Need Advice.
« Reply #15 on: June 10, 2021, 11:08:15 am »
Micha,

Thanks for your insight. I agree with all your points, it just seems to me that for something that is supposed to "certify" sharpness, being dependent on the user notion of "tight, but not too tight" is some kind of a loophole.

I'll try to experiment a bit to see how the bess value varies for a single knife with different - yet still complying with the "not overtight" requirement - settings, and let you know. Maybe it's negligible.

Offline cbwx34

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Re: Need Advice.
« Reply #16 on: June 10, 2021, 02:04:30 pm »
Re the BESS tester...
...
Did I miss something ?

Cheers,

Nick.

That... they have their own forum;)

Knife Sharpening Angle Calculators:
Calcapp Calculator-works on any platform
or, a couple of iOS Calculators

Offline Ken S

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Re: Need Advice.
« Reply #17 on: June 10, 2021, 02:37:03 pm »
Re the BESS tester...
...
Did I miss something ?

Cheers,

Nick.

That... they have their own forum;)

The BESS exchange is bessex.com. For more in depth BESS discussions, it is an ideal reference.

Ken

Online BradGE

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Re: Need Advice.
« Reply #18 on: June 10, 2021, 09:52:46 pm »
I made a video a few months ago showing the effects of thread tension on BESS score… And also how BESS scores can be artificially lowered by chopping down on the thread, rather than gradual progression of pressure.  On the latter point I managed to get a Mora basic down to 16 BESS 

https://youtu.be/dG2rQ6CjTyc


Offline tgbto

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Re: Need Advice.
« Reply #19 on: June 11, 2021, 08:14:36 am »
Re the BESS tester...
...
Did I miss something ?

Cheers,

Nick.

That... they have their own forum;)

The BESS exchange is bessex.com. For more in depth BESS discussions, it is an ideal reference.

Ken

I definitely missed that. Thanks !

I made a video a few months ago showing the effects of thread tension on BESS score… And also how BESS scores can be artificially lowered by chopping down on the thread, rather than gradual progression of pressure.  On the latter point I managed to get a Mora basic down to 16 BESS 

https://youtu.be/dG2rQ6CjTyc



Brad, this is a brilliant video that hadn't shown up in my results yet. Many thanks!


Offline Dutchman

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Re: Need Advice.
« Reply #20 on: June 11, 2021, 10:26:04 am »
I made a video a few months ago showing the effects of thread tension on BESS score… And also how BESS scores can be artificially lowered by chopping down on the thread, rather than gradual progression of pressure.  On the latter point I managed to get a Mora basic down to 16 BESS 
https://youtu.be/dG2rQ6CjTyc
After having seen the film, I wonder what the value of a BESS measurement means. Even the 'prestressed' measuring bridges do not give any unambiguous measurement.
In my opinion, the tolerance is near ± 30, but at least ± 10.

Online BradGE

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Re: Need Advice.
« Reply #21 on: June 11, 2021, 11:03:44 am »
I made a video a few months ago showing the effects of thread tension on BESS score… And also how BESS scores can be artificially lowered by chopping down on the thread, rather than gradual progression of pressure.  On the latter point I managed to get a Mora basic down to 16 BESS 
https://youtu.be/dG2rQ6CjTyc
After having seen the film, I wonder what the value of a BESS measurement means. Even the 'prestressed' measuring bridges do not give any unambiguous measurement.
In my opinion, the tolerance is near ± 30, but at least ± 10.

In my experience +/- 10 is probably fair - I doubt it’s as much as 30.  So difficult to know though, because are you measuring, exactly the same part of the edge, and/or did the first test impact the quality of the edge for the second test?  Certainly the operator has to carry the responsibility of working carefully to get good, useable results.  But as others have said, for comparing one’s own results I’m confident that my BESS 80 is sharper than my BESS 100…   But how my 80 compares to someone else’s 80… no way to know.  Only by using standard weights (100g etc) or the pre-tensioned clips can we narrow that gap a bit, but regardless we have to count on each other to not ‘chop’ during the measurement.
« Last Edit: June 11, 2021, 11:12:58 am by BradGE »

Offline micha

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Re: Need Advice.
« Reply #22 on: June 11, 2021, 11:52:52 am »
Hi Brad,

I agree, except for the pretensioned clips.
I wonder whether testing with a bit of slack in the line would lead to more commensurable results by eliminating the pretension factor completely.
But that's just a hypothesis for now. But I can't see any disadvantage in not having tension.

Maybe I'm missing something?
Mike

Online BradGE

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Re: Need Advice.
« Reply #23 on: June 11, 2021, 01:07:19 pm »
Hi Micha,

I’ll play with that idea of slack and report back.  I think there might be an issue that if the edge doesn’t land exactly in the centre of the test line then as you press down the apex will slice the media slightly laterally as it makes its way to the lowest point of the ‘V’ that will be created in the line…  But I’ll try it.

Regarding the pre-tensioned clips, you’re not the first person that doesn’t like them, but my experiences have only been positive so far…

Offline micha

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Re: Need Advice.
« Reply #24 on: June 11, 2021, 06:20:09 pm »
Brad,

I'm looking forward to hearing about your observations.
I just did some 50 tests without any measurable tension and found the results quite reproducible in a narrow range of +- 10 grams.

When tensioning the test line (arbitrarily, without using a weight) just with my fingers, the results tended to be lower, up to +40 grams .
Pretension up to 100 grams didn't have so much influence.

As it's way more comfortable to fix the line without notable tension, I think I'll keep to that.

I'd be interested in Mike Brubacher's thoughts, too, guess I'll drop him a line.

Mike