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  1. #301
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    And my small contribution
    Taken directly from
    Wikipedia

    Sarah "Tabitha" Babbitt (December 9, 1779 circa 1853) was an early American Shaker tool maker and inventor, including inventions for the circular saw, spinning wheel head and false teeth. It is contested whether she, or other Shakers, were the first to invent the circular saw. She was a member of the Harvard Shaker community.

    Some of you, may already have know this .
    Cheers Matt
    More power to the ladies I say

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  3. #302
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    Interesting ... presumably related to Babbitt metal and Babbitt bearings???
    Paul

  4. #303
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    Here's the data for the other makers in my collection to date. They cover quite a range from HRC 35 to just under HRC 55.

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

  5. #304
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    Rob

    It would be interesting to compare the major manufacturers secondary lines for HRC with their premium lines.

    For example, you have a couple of "Keystones" and a "Jackson" which were made by Disston (actually there was a William Jackson from New York who made saws, but the majority seem to be the Disston made saw). You also have a "Sheffield" which was an Atkins line and seems to be a good saw.

    Regards
    Paul
    Bushmiller;

    "Power tends to corrupt. Absolute power corrupts, absolutely!"

  6. #305
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    Quote Originally Posted by Bushmiller View Post

    It would be interesting...
    That sentence has gotten me into trouble and delivered rewards to me more times than I can count.

    I'm planning a comparative survey of the other major 19th century saw makers to go alongside my work with the Disstons. I'll add more saws as they're available and I'm able.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  7. #306
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    Excellent Rob

    Sorry to have potentially got you into "trouble," but i'll look forward to seeing any results. Lets hope the rewards outweigh the trouble.

    One ajoinder to make would be to stipulate whether the plates are tapered or not. I am not sure when taper grinding became commonplace, but the manufacturers certainly made a big deal out of it. "Fully taper ground" was a common cry.


    Regards
    Paul
    Bushmiller;

    "Power tends to corrupt. Absolute power corrupts, absolutely!"

  8. #307
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    Paul,

    No problem, I'll be sure to find trouble with help or no.

    Disston started taper grinding in the early 1860's. All of the post-1860 Disston handsaws are taper ground, no exceptions. None of the earlier Disston saws, handsaws or backsaws, have tapered plates.
    None of the other very early saws I have are taper ground such as this 1850-1857 W.B. Gregory saw (Need help identifying this saw maker).
    In fact, I just finished measuring the profiles of the three Acme 120 handsaws I haven't posted yet...

    Regards,
    Rob

    P.S. I bought that book "Handsaw Makers of North America" you mentioned. Thanks for the reference. Contains some useful information for my work but is still largely a botany.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  9. #308
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    Update: Added a few saws.





    I now have enough Atkins saws to be able to do some comparisons.



    Atkins saws in this sample are a little harder but significantly (P = 0.044) more (143%) variable in hardness.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  10. #309
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  11. #310
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    Thanks Rob for all your efforts.

    It is very informative and with your summary points to good reasons why Disston was such a successful company for more than 100 years. So now the question is how their data compares to their competitors.

    In the day the consumer certainly did not have the benefit of a Rob Streeper to tell them how good a saw really was. Consequently their evaluation was subjective at best and the victim of the Disston marketing machine at worst.

    I am most grateful for Disston's contribution because without them we would not be discussing the relative merits right here .

    Regards
    Paul
    Bushmiller;

    "Power tends to corrupt. Absolute power corrupts, absolutely!"

  12. #311
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    In both of the above the black lines are the upper and lower 95% confidence limits (quadratic fit).

    In the (much more confusing I know) upper plate are displayed the annotated data for hardness (center diamonds of each point) +/- S.D. (smaller red diamonds). The golden data points in both plates are golden era saws. The blue diamonds are Acme120's. The darker purple diamonds are No.7 (maybe pre-No. 77?) backsaws. The lighter purple diamonds are No. 12's, note the small S.D.'s. The single black diamond is a No. 77 backsaw with a legible etch.
    The lower plate presents the upper and lower 95% confidence intervals normalized to the overall average hardness of the test set, HRC 49.52.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  13. #312
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    Quote Originally Posted by Bushmiller View Post
    One ajoinder to make would be to stipulate whether the plates are tapered or not. I am not sure when taper grinding became commonplace, but the manufacturers certainly made a big deal out of it. "Fully taper ground" was a common cry.
    In amongst the 35 slides of graphics, tables and summary sheets for this dataset I've got your answer.

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

  14. #313
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    Thanks Rob

    That is a little earlier than I had imagined. It obviously all revolved around a suitable machine.

    Regards
    Paul
    Bushmiller;

    "Power tends to corrupt. Absolute power corrupts, absolutely!"

  15. #314
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    Quote Originally Posted by Bushmiller View Post
    That is a little earlier than I had imagined.
    The very first patent was one in 1836 by Hoe. I haven't managed to track it down yet but Barley cites it as the earliest American patent on saw grinding.
    After Hoe the next patent describing a means of saw grinding that I'm aware of is US16223 by Andrews in 1856 though the use of a ground or relieved blade is discussed in the 1851 Crosby grant. I posted the Andrews patent over on the thread I made discussing taper grinding of saw blades here The history of taper grinding of saw blades.


    This figure shows the numbers of US patents related to saw grinding or tapering over the years, Hoe is not included as it was before 1840. A few are included that make use of rolling to create a tapered plate.
    The majority of the 19th century patents were by or were assigned to Disston. Prior to 1860 Disston has a number of patents for the design of various types of saws such as the combination square, level, ruler saws like the No. 43. The 1860 patents on grinding are the first in a long series of patents concerning manufacturing methods that issued to Disston.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  16. #315
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    Default Comparison of Disston Golden Era saws to George Bishop saws.

    N for the Bishop set is low but the result is statistically significant, Bishops are softer.
    In the above the H% is supposed to be capital Delta% - graphics glitch.
    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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