Page 3 of 47 FirstFirst 1234567813 ... LastLast
Results 31 to 45 of 696
  1. #31
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default

    Pulling out the datapoints for the jigs having mechanical stability problems clarifies the importance of wheelbase.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  2. # ADS
    Google Adsense Advertisement
    Join Date
    Always
    Location
    Advertising world
    Posts
    Many





     
  3. #32
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default

    Today I had the opportunity to burrow into the part of my shop where I stored the third Craftsman branded chisel needed to fill out this table.
    As above these results are derived from 5 measurements each of 3 chisels of each type and manufacturer. The Narex mortise chisels show the highest group standard deviation because one of the chisels was surprisingly soft at HRC ~51 and the other two chisels were at HRC ~57.

    The hardest chisels overall were the Takahashi white-paper steel fishtails and the softest, even leaving out the odd ball, were the Narex mortise chisels.

    Also of note are the results for the PM-V11 chisels. They're softer than the manufacturer stated range of HRC 61-63 and they also have the lowest intra-chisel variability and the second lowest inter chisel variability - pretty good QC.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  4. #33
    Join Date
    Nov 2004
    Location
    Millmerran,QLD
    Age
    73
    Posts
    11,095

    Default

    Rob

    Do you think that some chisels have deliberately been made softer (ignoring the quality control aspect for the moment)? For example, the Narex are a mortise type and intended to be hit hard. They may have been deliberately been made softer, but possibly tougher, to resist chipping or fracturing under duress.

    I am surprised that the manufacturers claims are not met. Perhaps they don't realise that everybody conducts hardness tests on their products to ensure they are complying with their advertising.

    Interesting stats Rob. I am still mulling over the significance of your previous post and the effect of jigs on attainable sharpness.

    Regards
    Paul
    Bushmiller;

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

  5. #34
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

  6. #35
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default

    Paul,

    For the recently made chisels I would tend to think that their final hardness values are intentional. Leaving out accidents such as the Ray Iles chisels I tested that were uselessly soft I think that most manufacturers, particularly the larger ones, have SOP's defining their processes and products and QC people checking the results, or at least I hope they do.

    Hardness testing is easy to do and, given the de-industrialization of the United States, there are a lot of good used hardness testers available at bargain prices, in fact they've become a bit of an hobby for me.

    I checked the PM-V11 chisel data on a second instrument and the results were consistent. The LV chisels are softer than billed. They are however unbelievably tough. I bought this set used and the previous owner had been thoughtful enough to apply crooked hollow grinds, sloppy secondary bevels with the added bonus of back-bevels (?!?). Removing all of that diligently applied mess was a real chore even with an XC Duosharp plate. I felt the effort in my shoulders the next morning.

    I don't understand what's going on with the LV chisel in the data shown above. It starts out and progresses in the way I would expect and then about 5000 grit things go non-monotonic. Some of this is likely due to the jig (Veritas Mk II), some to me, and some to the chisel metallurgy. I plan a comparison to the LN 1" bench chisel, hopefully it will take a bit less effort to accomplish.

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

  7. #36
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default

    I decided to circle back to the 12,000 stone but use the General Tools #810 jig instead of the Veritas Mk. II. Here are the results.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  8. #37
    Join Date
    Apr 2001
    Location
    Perth
    Posts
    10,810

    Default

    Rob wrote:
    A number of things are readily apparent. First, most sharpening jigs can't make effective use of stones > 8,000 grit or so. The longer jigs however allow exploitation of the very fine grit stones > 12,000. Price of the jig is no guide.
    Rob, are you saying that downforce is necessary to extract the best from sharpening media?

    What is it about the width of the wheels that determines how they work? .... Do narrower wheels limit the control, and thereby the amount of downforce?

    I have been a bit confused about the bevel angles used. Did you determine which bevel angle worked best for each steel, alternatively for each chisel, and how have you linked this to "sharpness" and edge holding? How are you determining these areas?

    Regards from Perth

    Derek

    Visit www.inthewoodshop.com for tutorials on constructing handtools, handtool reviews, and my trials and tribulations with furniture builds.

  9. #38
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default

    Hi Derek,

    In my fiddling around with this I've found that applying a lot of downforce is detrimental to the development of maximum sharpness from any given stone. I'm applying no more than 10 lbs. or so on the coarser grits and less on the finer. I've tried 'a little' and 'a lot' of pressure without success.

    The bevel angles for the chisels in the performance post above weren't chosen, that's simply what they are. I don't see any pattern of included angle on edge holding, most likely because I haven't been trying to probe it by using different angles on the same chisel in different types of wood yet. I]ll try to address that aspect when I move to the second major phase and look at hardness, included angle and alloy as the influence edge retention.

    The wheel width is driving down ultimate sharpness on the Somax/Eclipse type jig through allowing wobble side to side. Jigs with wider track widths make sharper edges.

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

  10. #39
    Join Date
    Apr 2001
    Location
    Perth
    Posts
    10,810

    Default

    Hi Rob

    Those are interesting comments - and provocative .. to me

    My experience supports your view that heavy downforce will negatively affective sharpening. I do wonder how this is significant in regard to steel and edge life. I have an image of Paul Sellers wacking away at his diamond plates - which are known to create deeper scratches than waterstones - and then strop for his life on charged leather. He does nevertheless achieve sharp edges.

    Are you saying that you have not accounted for bevel angle? For example compared like-for-like, or matched angles to manufacturers recommendation? If so, that could invalidate any comparisons of edge holding and performance. Not only do different steels have a preferred bevel angle, but different bevel angles will perform (cut) differently from one another.

    With regard the wheel width issue, that introduces a question of whether experience and skill are a factor in comparing the various honing guides: how the guide/blade is held, where one places pressure/downforce, and how steadily they are pushed/pulled. A 1" chisel is pretty wide, and holding the bevel end steady should be straight forward if pressure is placed at the blade edge end rather than on the honing guide. On the other hand, a 1/4" wide chisel may prove to be a different kettle of fish. Ideally, all honing guides should be used in a comparable way. My concern is that there are some subjective issues here that are not being controlled. Would it be better if just one honing guide was chosen?

    I find all this very interesting, thanks.

    Regards from Perth

    Derek
    Visit www.inthewoodshop.com for tutorials on constructing handtools, handtool reviews, and my trials and tribulations with furniture builds.

  11. #40
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default

    Derek,

    This part of the study was originally conceived as an exploration of the characteristics of chisels manufactured by others. I haven't addressed the bevel angles, only measured them, because my goal is not to determine what angles are best for the chisels I have that were made by others but rather to study how their chisels perform as they set them up.

    The next volume of this study will probe hardness, bevel angle and alloy on chisels that I'm going to make. I've bought O1, A2, D2 and 440C stock and plan to make four 1" chisels. Once I get them formed and make up some handles I'm going to heat treat each through a range of hardnesses from HRC ~65 (or whatever the max on quench is) down to about HRC 55. At each hardness I'll evaluate edge retention as a function of bevel angle in two or three types of timber, pine and hard maple for sure and perhaps Verawood. From the results I hope to divine the best angle/alloy/hardness/wood combinations

    I started out with the Somax/Eclipse because it is what I have most often used in the past. I chose 1" chisels to test for precisely the reason you site, it's easy to keep that width stable, or at least I thought it would be. As my results unfolded however it became apparent to me that the jig was a limitation. So I decided to dig into the mess I call my workshop and pull out some additional jigs I have but haven't used very much. Of course, knowing which jig is best is going to enhance the results obtained from the study of the chisels I plan to make.

    My preference now is the Veritas, really a sweet and well thought out tool, it just doesn't have the needed wheelbase. The antique hinged and General Tools jigs are a PITA to set up and use, particularly with different thickness stones. The Kells are also very nice and beautifully made, unfortunately they lack wheelbase and will only work with chisels having straight sides and for chisels that have front and back faces that are coplanar along the axle axis, otherwise the bevel of the chisel skews when it is held above the axle to maximize wheelbase. The BCTW is the only tool from them I have that I'm disappointed with. It works but because of sloppiness of the roller adjustment mechanism it's useless for attaining a fine edge. I consider the Somax/Eclipse and Pinnacle jigs to be junk now.

    It's going to be a long slog but I think it worthy, instrumental analysis is my thing. There's so much mythology in hobby woodworking that it reminds me very much of the descriptions I've read of theology in the Middle Ages to Renaissance. Microbevel arguments for instance seem to me to be a lot like the famous/infamous fairies on pinheads discussions, everybody has an opinion but numerical data is very thin to non-existent.

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

  12. #41
    Join Date
    Mar 2015
    Location
    Melbourne, Vic, Australia
    Posts
    1,255

    Default

    Quote Originally Posted by rob streeper View Post

    Also of note are the results for the PM-V11 chisels. They're softer than the manufacturer stated range of HRC 61-63 and they also have the lowest intra-chisel variability and the second lowest inter chisel variability - pretty good QC.
    This testing got my interest up, so I tested the hardness of a PMV11, 1inch chisel on a calibrated Wilson hardness tester at work. I measured 62, 61.8 and 61.8 HRC. I also tested a BARR framing chisel at 61 HRC.

    Cheers, Dom

  13. #42
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default

    Dom,

    Thanks very much for doing some independent testing. I believe that you are the first person to respond to my data with data.

    The set of PM-V11's I have came to me used, I have no idea when they were made or what happened to them since they were made. I tested three of the chisels with 5 measurements each with my New Age hardness tester. The measurements were taken at points from just below the shank down to as close to the cutting edge as I could get. I suspected the results at first too so I came back and re-measured on my HR-150A, same result. I went a bit further and took a couple of readings with my superficial tester on HRN45 scale, same result.

    This is my current calibration curve for the New Age tester.


    The other instruments are also calibrated with similar results. All of my reported values are corrected to the standards to compensate for slope and intercept variability due to the instruments.

    The divergence of our results probably stems from inter-batch variability or process changes that may have occurred between the time your test chisel was made and mine. Each of the chisels I have that I tested was very similar to the others, results that are reflected in the statistical data above. The consistency within and between chisels is impressive, their failure to meet the hardness specification, likely to be a functionally a trivial difference, is why I wrote "pretty good QC" rather than "impressive QC".

    I have very high hopes for these chisels, so much that I chose to purchase the 1/8" and 3/16" size chisels that didn't come with my used five piece set. I'll check them and report the results.

    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. #43
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default

    Continuing the study from post #36 above here are the results with the Shapton 30,000 grit stone.



    Again, no joy. This chisel/jig/stone combination just don't play well together. Best to stop with the 12,000 grit Naniwa and either the General Tools #810 (slightly better/sharper) or the Veritas Mk. II jig (vastly easier to use).
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  15. #44
    Join Date
    Apr 2001
    Location
    Perth
    Posts
    10,810

    Default

    Each of the chisels I have that I tested was very similar to the others, results that are reflected in the statistical data above. The consistency within and between chisels is impressive
    Hi Rob

    This reflects one of the advantages of PM steel: it is a sintered steel rather than a cast steel. This is a much more precise method, and variations are likely to be reduced to a minimum.

    Regards from Perth

    Derek
    Visit www.inthewoodshop.com for tutorials on constructing handtools, handtool reviews, and my trials and tribulations with furniture builds.

  16. #45
    Join Date
    Mar 2015
    Location
    Melbourne, Vic, Australia
    Posts
    1,255

    Default

    Hi Rob,

    I'm a little confused by how you are getting your 95% confidence bounds, as it does not appear you are using anything close to 2 standard deviations from the mean to derive this?

    Cheers,

    Dom

Page 3 of 47 FirstFirst 1234567813 ... LastLast

Similar Threads

  1. Rust removal with Citric Acid - pictorial step by step
    By FenceFurniture in forum HAND TOOLS - UNPOWERED
    Replies: 46
    Last Post: 4th April 2018, 10:58 AM
  2. Step by step on making a Square to Round transition
    By Al B in forum METALWORK FORUM
    Replies: 34
    Last Post: 19th September 2012, 11:32 AM
  3. Step by Step Pyrography Project Getting Back on Track
    By David Stanley in forum PYROGRAPHY (Woodburning Art)
    Replies: 2
    Last Post: 25th September 2011, 12:53 AM
  4. Excellent step-by-step instructions for MAloof-style rockers
    By TassieKiwi in forum WOODWORK - GENERAL
    Replies: 22
    Last Post: 14th December 2006, 01:57 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •