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Thread: Hardening of sawplates
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14th January 2015, 11:57 PM #121
Rob
I feel a few comments need to be made in the light of developments on this thread and indeed with the menace of Sawmillcreek looming in the background.
Firstly I would like to thank you for taking such a huge amount of time in preparing your testing and subsequently posting the information here on the Forum. I do know how long this takes and how much effort is involved.
Sometimes I think we, actually all of us, forget that this Forum is a facility for discussion. It would be hopeful to think that all out comments are going to be favourably received, but I do believe we have a right to expect some civility. My perspective is that all your testing has been performed with integrity foremost in your mind.
It does seem to be very unfortunate that some people are so blunt in challenging findings. I have noticed that it is a very prevalent trait amongst the "cousins." Don't worry: Australians can be blunt too and the Woodwork Forums have had their fair share of stoushes!
As to the testing itself I do see an inconsistency with the apparent hardness of the plates and the ability to file them. I remember being told in carpentry to measure several times and then step back and see if it looks right. If it still doesn't look right, measure yet again. If we need a difference of RC15 between the plate and the file, something may not be quite right with the findings as that would indicate a maximum of RC50 for the sawplates.
However the relativity may still be there between the plates. I am assuming that any discrepancy is the same for each plate. Consquently the plate that came up with a low hardness is still an issue even if the value itself is incorrect. I'm not sure if I have explained that satisfactorily.
Not everybody is set up to conduct laboratory style testing. Readers must accept that testing is available at a "entry level" basis. I think it is up to you regarding publishing names. In these times where litigious activity is a profitable sideline for many, I would be keeping such information under wraps until I was sure I could back up statements. It is not quite the same as if you buy a power tool and it fails (smoke escapes from the motor for example).
Again, you have my thanks for attempting this testing and enduring what must have been a very trying and disappointing time. I am a registered member of Sawmillcreek, but I have never posted there and in truth rarely visit: Normally it would only be if a link is provided. I am afraid that attitudes such as displayed on that Forum are not conducive to interaction. I doubt I will be inclined to contribute there until such time as the culture changes, but I am not anticipating they will miss my presence .
Regards
PaulLast edited by Bushmiller; 15th January 2015 at 07:08 AM. Reason: Misprint on figures. Max plate hardness of RC50.
Bushmiller;
"Power tends to corrupt. Absolute power corrupts, absolutely!"
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15th January 2015, 12:03 AM #122GOLD MEMBER
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Well, you might be in luck! I have nearly ceased posting there (and intend to entirely), and I think George's interests are more in the area of metallics and as time goes on, you'll run into him only if you frequent machinists forums. It will be free to go back to "no questions asked, any answer is correct" status after that, with an occasional barb probably shot by Warren Mickley (a consummate professional) and perhaps some of the other professionals who go in and out.
A bit of disagreement is what lubricates the brain to buckle down and really think.
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15th January 2015, 12:15 AM #123Deceased
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I just added some info into Robs Disston D-8 replica posting.
Stewie;
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15th January 2015, 01:00 AM #124
Okay, now on to the subject of the ethics of my withholding the identity of Maker 3. In principle I agree with Stewie. Everyone should have the benefit of knowing who Maker 3 is with the very important proviso that I only tested one saw from each maker. Unfortunately I do not live in a country or state where such honesty goes unpunished.
I refer you to this: http://www.pbs.org/newshour/bb/law-j...-fooddef_1-20/
For those who don't want to read the linked transcript the synopsis is: Oprah Winfrey said some things on her television show that the Beef Industry didn't like. The subsequent court actions proceeded for years and consumed millions of dollars in legal fees.
Lawsuits of this type are now called SLAP's. In fact there is a Wikipedia page devoted to them: http://en.wikipedia.org/wiki/Strateg..._participation
I do not have millions to spend on attorneys.
I understand that many of you are not aware of the legal situation where I live but let me assure you that such laws are being used by monied interests to bring spurious lawsuits against people who complain.
Thus I'll throw down the gauntlet: If any of you want to fully indemnify me for any losses, including my time (at the rate I earn in my real profession, not my saw making) that I might incur as a result of such suit being filed against me then I'll fess up. Be aware however that you might lose everything you own including your money, your business, your job, your home, your family and every material item you posses.
So now who is willing to step forward?Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.
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15th January 2015, 01:56 AM #125GOLD MEMBER
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In your estimation, do you feel that possibly the highest profile and most public case of the oprah beef debacle (IIRC that was in reference to BSE) is a reasonable comparison vs. mentioning the hardness of a saw plate?
Did you at least tell the manufacturer that you tested a saw plate of theirs in the 30s? Comparing this to the beef case (or the later pink slime case) is a bit dramatic.
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15th January 2015, 02:18 AM #126
For those who are disturbed by my results on the Disston saws, remember I was fully up front about my realization on the limitations of testing under the handles.
The occasionally vituperative rejection of my results, rejections which I note were unsupported by carefully qualified data such as mine, remind me of the Procrustean bed. http://en.wikipedia.org/wiki/ProcrustesInnovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.
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15th January 2015, 02:36 AM #127GOLD MEMBER
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It's been interesting Rob, but it's getting a little too weird for me. I hope you get your data corrected and show users relevant numbers for the disstons, it will help your credibility. If you don't, that's up to you.
Good luck with the saw making.
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15th January 2015, 02:37 AM #128Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.
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15th January 2015, 03:50 AM #129
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15th January 2015, 05:57 AM #130Member
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Yes I think you are missing something. It certainly isn't a scientific report and he is a bit foggy in some of his formulations, but lower down in the thread you can read these explanations:
3 whacks at 1 spot on 1 sample. Average the 3 tests and that's
1 reading. Then we took other readings on different areas of the
sample. Eliminated highest and lowest, averaged the rest and that
is the number given on the list.
[...]
The saws had an even hardness. 3 tests on one spot done on 4
different areas of the same sample. The average of the 3 tests
varied only by 0.3 HRC from one area to the other. The D8 had
higher variance but I don't have the numbers here.
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15th January 2015, 06:19 AM #131GOLD MEMBER
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His three values are more relevant, and his hardness testers (the C tester), miles more accurate. I think you are getting swept up in what you can plug into your statistical program without understanding the validity of the data.
You may note his comment that except for the D8, the saws have even hardness. We don't know if that's at three places along the tooth line, three along the spine, but a betting man would assume not 3 different areas under the handles (anything is possible, though).
The saws had an even hardness. 3 tests on one spot done on 4
different areas of the same sample. The average of the 3 tests
varied only by 0.3 HRC from one area to the other. The D8 had
higher variance but I don't have the numbers here.
Three tests of three strikes with the mean of each of the three tests varying by 0.3 HRC is very little.
Now, you've mentioned you won't test the saws at the tooth line because you don't want to put dings in your saws. There are, however, numerous sales of junk saws on ebay that are just blown out versions of otherwise professional saws. I would imagine you could probably find half a dozen saws shipped to you in one of those lots for $50 and get relevant data, something that a meaningful conclusion would be drawn from. I'll bet you could easily find five people who would send you ten bucks on paypal to fund finding saws that are otherwise a no-sale that you can strike at the teeth. I sure would. I don't know if I have some old main line saws that could be sheared (saws with kinks, etc) that you could test, but I might. If I do, I will send the parts of their plates that fit in a flat rate box or mailing tube, just in the interest of getting relevant data.
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15th January 2015, 09:46 AM #132
Okay David, here's the C scale analysis. I used the same pieces of 0.035" 1095 that I described above.
I recently had to move my B/C tester and never checked it. Today I did a quick calibration check and found it was off. I adjusted some and got the machine linear albeit with a non zero intercept and a slight deviation in the response slope. Easily corrected numerically and a very time consuming job to adjust the tester mechanically so I did the correction numerically. Ambient temperature was 17 oC.
Everything worked fine and the results are convergent with the N45 results.
https://video.search.yahoo.com/video...&hsimp=yhs-001Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.
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15th January 2015, 09:55 AM #133
Want to form a peer reviewed tool making journal?
I just had a thought ladies and gentlemen, given the amount of work I put in on this hardness analysis and the complexity of other projects I see posted on this site would anybody be interested in forming a group to prepare article type postings here?
Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.
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15th January 2015, 11:28 AM #134Deceased
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Hi Rob. If this thread is an example of the group activities you have in mind, you can count me out.
Stewie;
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15th January 2015, 12:03 PM #135
Hi Rob,
I'm all for researching materials and methods to make better tools, but I don't see the need to be quite so academic about it. You don't need to defend every statement you make, you just need to understand that there are others who have knowledge and experience that should be listened to, thought about, and digested. It's not about statistical analysis of the data, it's about understanding and interpreting the data.
All of this thread could be summarized in just a short post. Something like, I have found that hammered saw plate exhibits a higher surface hardness. Then you could go on to describe ( in brief ) the measurements. I wouldn't even report the other sawmakers plate hardness results.
Like Stewie, I'm more interested in making saws, and what makes a saw perform and feel right. It's about touch and feel, things that aren't so easily measured.
Ray
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