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  1. #136
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    Hi Rob. I wont be contributing any further on this thread. The fact that you are also in competition with those you accuse of making sub standard work does concern me greatly.

    regards; Stewie.

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  3. #137
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    Quote Originally Posted by RayG View Post
    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
    Ray,

    I produced the data and analyses I have to provide information to clarify reality. I am very concerned that I'm taking so much criticism for having done so. Everything about my data, my postings, my style and even my character has been questioned, sometimes in a rather mean spirited way.
    If I'm equipped to offer evidence that counters an objection made to me about something I write or present I do it. I have done it exhaustively here because of the unrelenting nature of the criticism I and my postings have received.
    As I have explained here and in other places I began the inquiry I have because I found a saw in my collection that was produced by a custom maker was substandard in my opinion. I made no secret of the fact that it was a single saw. N = 1 is not even the beginning of a trend.
    Opinion is just that and nothing more. Opinion is easily dismissed or ignored. An opinion on the internet in the absence of personal knowledge of the expertise level of the person who offered the opinion is useless.
    Data, however limited in scope, is not opinion. To me, people who are afraid of what data reveals or suggests are in fact afraid of the truth. Data must always be carefully considered and analyzed. I have presented data and analyzed it, creating posts that will walk someone who is less knowledgeable through the techniques and concepts I have applied and maybe allow them a degree of understanding.
    My economic interest in custom saws is miniscule. I've sold a grand total of 8 saws over two years. I do this work only when I'm not busy with other work, which I was throughout the summer and fall of last year. If my tiny production or my posting scientifically acquired information about one bad saw from one custom maker is all it takes to send shockwaves through a cottage industry such as this I'm really surprised.
    Boutique saws are luxury items. People buy them because the want them, they don't need them with the exception of a small group of specialist woodworkers who use them to produce things for sale.
    Functionally there is little difference between a Lee Valley plastic backed dovetail saw and a high end piece of artistry such as others here display in their posts. The artistry contributes nothing to the practical end of cutting wood. Esthetics is important, but so is function. You know my posts from the past and I tend to focus on functional aspects because it's my strength and, as I've said on other threads here, I don't feel my artistic sensibilities are as advanced as some of you guys.
    The drift of the criticism makes me feel that there is a part of the community that is interested in technical issues and a part of the community that feels threatened by those who post such matter. Tool making should be more than just a beauty contest in my opinion. Neglecting the technical side of a subject or attempting to silence those with an interest in the technical aspects of an area does nobody any good. Now I will write to Stewie.

    Thanks for your time,
    Rob
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  4. #138
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    Quote Originally Posted by planemaker View Post
    Hi Rob. I wont be contributing any further on this thread. The fact that you are also in competition with those you accuse of making sub standard work does concern me greatly. regards; Stewie.
    Oh cripes, I had a long message here for you but my browser just crashed. I'll start again and submit several times so I don't lose my work.

    Stewie, I am genuinely sorry you feel that way. It was never my intention to alienate you or anyone else, here or on Sawmill Creek.

    My motivation to do the investigation was genuine, I wanted to know why the Maker 3 saw didn't work for me. I never made any secret of the fact that this was only one saw.

    I feel that your repeated demands to reveal the identity of Maker 3 are in effect demands that I place myself in a position of personal financial liability to avoid creating questions in the minds of your potential customers. In other words, I feel that you are asking or demanding that I sacrifice my serious interest in service of your vague concerns. I feel that your are being unfair to me.

    I knew from the start that my posting this information and the datasets and analyses I have would be controversial but nonetheless I did it because I felt and still feel that the much broader community of saw aficionados deserved to know that I had one bad saw. There are far more saw buyers than there are makers so out of a desire to do the greatest good for the greatest number I chose to put myself in front of the other saw makers and tell my story. I knew that I needed to be well prepared and I feel that I have done a pretty good job of presenting, in a dispassionate and analytical way, data that supports my anecdotal observations. (Crashed again!)

    I have observed an interesting phenomenon in the course of this exercise. On SMC I got a lot of criticism on the open thread and very little in the way of support. However, several members sent me PM's that were very supportive. Here I've gotten both criticism and support both openly and via PM's but the relative numbers of each in each communication channel have been roughly the same.
    Avoiding any nationalistic issues because both sites have users throughout the world I think that SMC is really a place where a clique of like minded graybeards are bullying everyone else, especially the newcomers. One fellow wrote to me and told me that my analysis was correct. He did criticize my form however. He told me that he had extensive experience in the steel industry and he explained himself. I don't know him from Adam of course but he sounded genuine. In addition one of the moderators corresponded with me and he as well supported my findings and asked me to continue posting. He said he saw nothing wrong or abusive in my posts. Oh well, I guess manners are, at least in part, a matter of personal taste. Much like personal tastes in the aesthetics of saws.

    I think the SMC clique does themselves great discredit but I doubt that they have ever thought about their treatment of others, most of whom they don't know.

    That's why I like this forum. People are generally more reasonable. Maybe it's the color scheme.

    Nonetheless, if you choose not to correspond with me I'll respect your decision and not bother you.

    Cheers,
    Rob
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  5. #139
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    Hi Rob. I see no reason why there shouldn't be normal correspondence on other threads. I have only stated I have an issue with the content of this thread.

    The sooner we can all shift our focus back to the positives within our saw making work, the greater the chance we have of encourage other forum members to try their hand at learning a new skill set.

    regards; Stewie.

  6. #140
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    Quote Originally Posted by planemaker View Post
    Hi Rob. I see no reason why there shouldn't be normal correspondence on other threads. I have only stated I have an issue with the content of this thread.

    The sooner we can all shift our focus back to the positives within our saw making work, the greater the chance we have of encourage other forum members to try their hand at learning a new skill set.

    regards; Stewie.
    Thanks for your consideration Stewie. I have been corresponding with DW on SMC in an amicable way. He has offered to source some Disstons for testing and send them to me. I asked him to post pictures of the saw blades that he finds so that everyone can provide their input as to the best methods for testing them. Your input would be appreciated.

    Cheers,
    Rob
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  7. #141
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    I think we have taken a good turn here. I've proposed to Rob that we find some saw plates, clean ones that have no scale (i.e., are bright near the tooth line) and that can have the teeth sheared off so that a good solid result can be had near the tooth line.

    In the US, people have apparently never been more proud of run of the mill saws. In the case that we cannot find anything, I will buy a couple of decent saws and send them to Rob so that we have clean plates on quality saws from disston's best quality era (which to me is about 1885 to 1935) that can be struck at the teeth.

    The consistent results from struck 1095 are enough to convince me that strikes near the saw teeth will give us reliable data.

  8. #142
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    Hi Rob,

    There's a test that could be easily done, if you are up for it?

    Take a piece of hammer hardened 0.032 1095 ... and test it with different loadings .. 15N 30N 45N and 150Kg Rockwell C.

    What I'm expecting to see, is higher Rc readings for the lighter penetration loads. This would indicate that the work hardening is occuring more at the surface of the plate, which might go some way to explaining how a saw that reads 60+ Rc can still be filed.

    Ray

  9. #143
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    Quote Originally Posted by RayG View Post
    Hi Rob,

    There's a test that could be easily done, if you are up for it?

    Take a piece of hammer hardened 0.032 1095 ... and test it with different loadings .. 15N 30N 45N and 150Kg Rockwell C.

    What I'm expecting to see, is higher Rc readings for the lighter penetration loads. This would indicate that the work hardening is occuring more at the surface of the plate, which might go some way to explaining how a saw that reads 60+ Rc can still be filed.

    Ray
    Ray,

    Right now I'm flexible in my time, part of the nature of my work. This is the reason why I go from posting frequently to hardly at all.

    I could do 0.035" but I don't have any 0.032" material in stock. The 0.035" already hammered and tested would be a good candidate and I could add additional measurements on the 15N and 30N scales across the three specimens. The data could be presented with the above to give a better appreciation. I also have the T and B scale indenters for the respective instruments.

    In the alternative or perhaps in addition to the above I have 0.015", 0.020" and 0.025" 1095 as well. More extensively I could test on the the three N scales and C scale on all thicknesses and observe the effects of plastic flow or is everybody settled with that part of the testing?

    The picture showing the plate after hammering above is the back side of the plate. I photographed the back side to show everyone that the distortion went all of the way through the material. This was achieved with relatively light hammering.

    My experience teaches me that, if the costs per data point are relatively low, it is better to have too much data than it is to have too little. This approach to experimentation has benefited me enormously on multiple occasions.

    Cheers,
    Rob
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  10. #144
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    Stewie,

    I don't know if you seen the posts but we're having a discussion about how to prepare and test the saw plates for mapping of hardness on SMC. I would appreciate your input.

    Thanks,
    Rob
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  11. #145
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    Yesterday during my thickness mapping I chose to do some more hardness tests on the three Disston hand/panel saws I have. These are Rc values. The measurements were taken with the Ames N/T tester on the N45 scale and converted.


    The values at the heel of he saw were taken mostly in the area under the handles. the values at the toothlines were taken an inch away from the gullets with one exception to avoid the effects of distortion and workhardening that exist closer to the teeth. The data from the heel of the saws from tooth to spine are suggest that these saws have work hardened regions running in stripes, no more than an inch wide, along the length of the saw.
    These observations suggest that a fairly fine scale grid of testing is needed for mapping the hardness of the plates, something like 1/2" X 1" coordinates.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  12. #146
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    Are you sure about these numbers? I see exteme variations. But I am not a mechnical engineer with experience in this field.

    The measuring device seems to work allright on the 1095, so why these variations? Something strange with the plates? Maybe you should just wait for the plates from David. These you can slather full of test points, you can first polish the etc.

  13. #147
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    Quote Originally Posted by Corneel View Post
    Are you sure about these numbers? I see exteme variations. But I am not a mechnical engineer with experience in this field.

    The measuring device seems to work allright on the 1095, so why these variations? Something strange with the plates? Maybe you should just wait for the plates from David. These you can slather full of test points, you can first polish the etc.
    Hi Corneel,

    I'm reasonably confident of each number. If a reading came back low or high I repeated the test at a nearby spot. In my first series of tests on these plates I produced data from a relatively small region and I followed the NIST recommended cross shaped testing pattern that looks like this (the site is editing out my spaces and distorting the cross):

    X

    X X X

    X

    Thus the high results I originally reported for these saws are likely due to the fact that I tested a smaller region of the saw plate under the handle, about 1.5cm on a side in the above pattern.

    Why did I do it? As George Mallory said: "Because it's there."

    When the plates arrive from David you can be sure that they will be tested extensively.

    Cheers,
    Rob
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  14. #148
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    I did a rudimentary cleaning of the saw plates (they are still dark) and forgot to tape them, but it doesn't matter, you can strike them all over.

    I also jointed off the teeth with a file. Dressing the side of the plates at the tooth lines lightly with a file might not be a bad idea, but I'll leave that up to you. That would remove any evidence of what was left of warpage from the set from the teeth.

    They're packed and I'll get them mailed sometime in the next couple of days, and you can strike the living daylights out of them over the weekend.

    I've sharpened both of these plates in the past and didn't note them to be out of the ordinary in doing any of that. You could file a notch in different edges of them with a triangular file for a reasonability test as a cross check to numbers.

    What would be interesting is if you strike the plates, and if you get a high reading, shear the plates and then try a triangular file to see if you can file at the high reading. If you can file a deep notch in a saw plate and you're getting numbers around 60 for hardness, you will know the method has a problem. if you get a high reading and also cannot file a notch without burnishing a file over, then you'll have good reason to believe the reading is accurate.

    I suspect anything that comes out around 60 on these saws will suggest surface hardening or an errant reading, they both have typical flex when bent.

  15. #149
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    I'd like to be clear in all of this. I am as unbiased as anyone on this subject will be. I have not made saws for sale, I have not made planes for sale, I have not made chisels for sale. I do not resell old saws for more than I paid for them, and have nothing to gain from any of this.

    I do not have any vested interest in the results other than seeing that they are correct because it is my belief that correct information as it's intended to be used is more important than my making friends on the internet. I came to the forums to learn and so do a lot of people.

    I know that a lot of forum members don't share priorities in that order, but as it's been painted that controversial results are threatening to saw makers, neither George Wilson nor I make and sell saws or sell used saws as a matter of practice. of course, as all of us, if I have excess old saws to sell, I will sharpen them and pass them along, but I do so at the cost it was for me to get the saws in the first place, and from time to time, I will add the cost of files used, but often I don't do that, either.

    While I come to the forums to learn and hope for the information to be as accurate as possible, and can be difficult for people who i think are presenting bad information, I don't come to the forums to be difficult in general.

    I think it's important that for me being one of the most critical to make sure that it's known that I am not a member of any "clique", I consider a few people from SMC as friends, but do not adopt other peoples' opinions as my own, regardless of who my friends are.

  16. #150
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    I decided to do some more experiments, this time with a new saw plate that I've described here: https://www.woodworkforums.com/f278/disston-8-replica-191254

    Since there is some uncertainty as to exactly what Disston meant when 'tensioning' was discussed and further since there are questions around the hardness measurements that I and others have reported in various posts I decided to take a fresh saw plate made of 0.035" 1095 steel and try to produce a pattern of hammer hardening similar to a Disston hammered plate.


    I started with a fresh, partially tapered 24" D-8 replica plate and I laid out some lines with a black paint pen as boundaries for hammering.

    Plate marked with hammering lines.jpg


    I used the 5 lb. sawyers hammer pictured and made overlapping l and - strikes in the areas above the black lines as indicated in the next picture.

    Hammer points marked.jpg


    Since this experiment requires data points taken at closer spacings I got out my 150 kg Soderfors anvil because it has a smoother face than the Peter Wright anvil I used before.

    Soderfors 150kg.jpg


    Hammering two runs of overlapping hammer strikes above both black lines on the face side of the plate caused the plate to bow.

    Plate after first pass of hammering on first side.jpg


    Doing the same pattern of strikes on the other side of the plate brought it back to near straight.

    Plate after first pass of hammering on back side.jpg


    This is the back side of the plate, the impressions from the hammer are just visible.

    back side of plate after first pass of hammering.jpg


    Then I laid out a test grid on the face of the plate. The grid boxes are 1" by 1/2".

    1 inch by half inch grid.jpg


    With the following coordinate system.

    coordinate system.jpg


    Since there is so much doubt about the Ames 2-S and since the plate material is > 0.032" the Rockwell C scale tester is appropriate. Here it is.

    Rockwell B C tester.jpg


    I tested at points like so, keeping off of the paint and marker lines to avoid any possibilities of errors.

    Test point locations.jpg


    For the first round of hammering I took relatively light strokes. Then I did a second round of hammering with more force and took all of the readings again at points about 3-5 mm away from the first test points. Here's the data. I attached the same in PDF format to make it easier to see.



    The green shaded areas of each table denote the zones subjected to hammering. The blue shaded zones are those zones adjacent to the hammered zones that contain test points within 3-4 mm of a hammered zone. The white shaded zones were not hammered.
    The first two tables present the raw instrumental data, the first for the 1X hammered readings and the second for the 2X hammered readings. The raw readings were corrected for the slope and offset calibration curve as I did in the above post discussing the 1095 experiment. The third and fourth tables are the corrected hardness readings for the 1X and 2X hammered tests respectively. Then I added in the offset for the effects of surface roughness. The 1095 experiment showed that the grinding of the plate caused the measured hardness values to read 2.18% lower than the actual hardness. Tables 5 and 6 incorporate this correction factor. The seventh table shows the difference between the corrected hardness readings of the 1X and the 2X hammered states. The 8th table compares the corrected and offset hardness values for the 1X hammered plate to the expected average hardness measured for 1095 above and the 9th table compares the corrected and offset hardness values for the 2X hammered plate to the average expected hardness for 1095. The 10th table shows red-dashed lines at the bottom of the hammered zones in approximately the same positions as the black lines painted on the plate overlaid on Table 9.

    You will note that the white, un-hammered zones appear harder. This is what I think is happening.

    http://www.shotpeener.com/library/pdf/2011009.pdf

    http://en.wikipedia.org/wiki/Bauschinger_effect

    http://dash.harvard.edu/bitstream/ha...pdf?sequence=1

    http://machinedesign.com/news/unders...s-autofrettage

    http://www.ewp.rpi.edu/hartford/user...es/Hojjati.pdf

    http://www.stsy.sjtu.edu.cn/uploadfi...%20tube%20.pdf



    D-8 Hammering Experiment hardness measurements 011915a.pdf
    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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