Page 9 of 12 FirstFirst ... 456789101112 LastLast
Results 121 to 135 of 167
  1. #121
    Join Date
    Mar 2004
    Location
    Brisbane (western suburbs)
    Age
    77
    Posts
    12,094

    Default

    Quote Originally Posted by rob streeper View Post
    .......I found another interesting Max Planck quotation today. "An experiment is a question which science poses to Nature, and a measurement is the recording of Nature’s answer."
    Yes, but always remember, she may give you a different answer to the same question, tomorrow!

    In the biological sciences, there's an old saying "never repeat a successful experiment" ...

    Cheers,
    IW

  2. # ADS
    Google Adsense Advertisement
    Join Date
    Always
    Location
    Advertising world
    Age
    2010
    Posts
    Many





     
  3. #122
    Join Date
    Aug 2004
    Location
    Brisbane
    Posts
    4,924

    Default

    I don't have a pony in this parade any more, nor do I want to, but I'm making available to you a pdf that once constituted some blog posts on plane mathematics that I posted on here a number of years ago that have not survived the various upgrades over the years. I prove mathematically why it is good to have a flat plane. It's mathematics, you'd think it can't be disputed, but good natured 'experts' reside in all corners of the internet. The usual arguments are that old masters made their masterworks with old tools that weren't perfect. This is typical generational arrogance, the inventors and users knew very well what they were designing and why. One only has to read the book The Perfectionistsow Precision Engineers Created the Modern World. The other comeback I used to hear was wood moves so why bother. This is a spurious argument rather more about designing assembled structures made of wood to survive the ravages of expansion and contraction, it really has nothing to do with bringing timber down to dimensional tolerances in the beginning eg, jointing and flattening boards for example. Finally, some people will say this is all too theoretical and just go and use the plane, to which I say I do, I use many types of planes and often, I am a practician. But I made the effort to understand the practical and the theoretical, either they can't or show willful ignorance, to which the only thing to say to them is MYOB. I see you have and will have this kind of interest in your posts too. The mathematics proves that the maximum errors of flat planes will always be less than a convex or concave plane and easier for a beginner or use (or for that matter anyone who pulls a new unfamiliar tool out of a box). The task of the planes we're talking about (so does not include compass planes, spokeshaves, tranishers etc) is to make things straight and flat (and flat can include smooth, and if using a short smoother this may not necessarily be completely flat - see the pdf for errors of short planes vs longer planes). The one and only task of the sole is to register the blade to the work at the beginning of the stroke and index the blade to the surface throughout the pass. that's it (OK and probably aiding good shaving formation at the mouth). If the sole is not flat it cannot hope to index the blade easily and consistently. So I applaud your efforts. You and I both have probably reinvented the wheel like many before us too. I have some divergence from you in methods. In my hands and many others hands, lapping has not produced good results. Since you have lapped and shown your sole is planar globally, not just locally (have you?) you obviously have made it work. I think you are in a minority. I have had people swear to me their lapped planes were flat only to come back to me after putting a good straight edge from toe to heel to find light escaping at either end. There are discussions on forums like Popular Mechanics and even this forum on this. A classic example of lapping producing convex shapes is in astronomical mirror making. You start off with two flat surfaces and abrasive and lap them. Without even trying, the top part you're moving becomes convex and the mirror becomes concave. Another thing, lapping assumes a consistent hardness of the casting, but in my scraping work I have found it not so. Some areas may be soft and scrape easily while other parts are hard. I do not know how one can compensate for this while lapping. But you have managed to do it nonetheless for n=1.
    Apart from the innate nature of lapping to produce convexity, you must be very careful with the way you hold the plane body so as not to flex the body while lapping. I made a post about this when I found it very easy to twist a plane body and showed it on spotting on a granite surface plate. Other repliers went further and supported this quantitatively with lasers. You can find the post by searching for 'Hand plane fettlers should read this' in this forum. This is not something theoretical, this is real.
    So, I scrape, I do not lap. Scraping is faster than lapping and less messy. It is singularly the best way for a back yarder to produce a flat surface once they have the tool. I have also used files for preliminary flattening and I will soon do a number 6 which is quite convex from lapping (I did it!) and I will test preliminary work by touching an angle grinder to the spotting.
    And my definition of flat is different from yours. I would not be aiming at wringing the surface. The idea of the plane sole is that it should index but also flow easily over a surface. You may find that a wrung surface may develop too much stiction. With scraping you can hollow select areas of the sole that do not need to bear and so ease sticition (And the nature of scraping is really to produce a bunch of coplanar spots, which kind of takes care of this anyway). This is the idea you see in Japanese wooden planes. This might never come up as a problem for you, or you might find some timbers suffer and others don't. I think all my posts on scraping planes have gone but I still have many photos if you want some.

    Good luck on your journey and always question and provide evidence.
    Attached Files Attached Files

  4. #123
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default

    Hi Michael,

    Thanks very much for your contribution. Yes, globally the sole of my plane is flat, at least within the sensitivity of the tools I have available to measure it. My largest optical flat is only 6" and this plane is ~7" long.

    Unsurprisingly perhaps I have been thinking about the very same issues discussed in your attachments. For instance, would it not be better, at least as far as achieving a flat surface goes, to have a square heel on planes intended for making flat surfaces, such as is done on Japanese planes? The round heel would seem to create a liability to transverse rolling of the plane body in use creating corresponding inhomogeneities in the finished surface. I could also see the rounded heel being beneficial if the blade is cambered. What do you think?

    If you have additional results or theoretical explorations please feel free to share them here.

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

  5. #124
    Join Date
    Aug 2004
    Location
    Brisbane
    Posts
    4,924

    Default

    Quote Originally Posted by rob streeper View Post
    Hi Michael,

    far as achieving a flat surface goes, to have a square heel on planes intended for making flat surfaces, such as is done on Japanese planes? The round heel would seem to create a liability to transverse rolling of the plane body in use creating corresponding inhomogeneities in the finished surface. I could also see the rounded heel being beneficial if the blade is cambered. What do you think?

    Regards,
    Rob
    No. The sole behind the mouth is flat, the blade leaves the work while the largest part of the sole still bears positively on the work, or should do. If there's any tendency for the plane to rock on the curved (in plan view) heel then you are planing wrong.

  6. #125
    Join Date
    May 2008
    Location
    Australia
    Posts
    2,357

    Default

    For those of you that wish to move away from lapping the sole to scraping the sole;

    YouTube

  7. #126
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default

    Now with the blade back lapped with 9 micron compound.

    Note that the first 5 cuts at each shaving thickness exhibit the lowest standard deviation, I think this means that the plane will now produce a smoother surface than I can.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  8. #127
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default Quick check with spotting compound

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

  9. #128
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default

    It took a while to scrape the blade bed flat because I could only approach it from the ends of the plane but I think I got pretty good contact.




    The two pads on either side of the adjuster slot were very high on this plane, I removed a lot of material off of them to get the blade to lay flat on the forward part of the bed.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  10. #129
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default

    Cleaning up my phone pictures and saw that I did take a pic of the plane with the 6" flat wringing down. The interference bands are somewhat harder to see because the flat is made of Zerodur which is light amber in color.

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

  11. #130
    Join Date
    Nov 2011
    Location
    Melbourne
    Posts
    6,973

    Default

    Quote Originally Posted by rob streeper View Post
    It took a while to scrape the blade bed flat because I could only approach it from the ends of the plane but I think I got pretty good contact.




    The two pads on either side of the adjuster slot were very high on this plane, I removed a lot of material off of them to get the blade to lay flat on the forward part of the bed.
    Rob,
    I think I missed something here?
    Have you flattened the back of plane iron, then used that to reference(blueing)the blade bed for scraping??.

    Cheers Matt

  12. #131
    Join Date
    Mar 2004
    Location
    Brisbane (western suburbs)
    Age
    77
    Posts
    12,094

    Default

    Rob, I wonder if perhaps you've eliminated some bed geometry that was intentional? That top bit may have been deliberately machined slightly high, so that the lever cap bears down on it, ensuring the clamping force is directed across the cutting end of the blade end & the top only?

    Just a thought, influenced by Karl Holtey's custom of putting a metal plug in his infill beds under where the thumbscrew bears on the blade assembly. It sits slightly proud of the bed, so the lever cap pushes the blade against the blade block (the extra chunk riveted to the sole behind the mouth), and the plug only, producing a very stable 'tripod' effect. I've been tempted to give it a try myself, because it would make life a bit easier than trying to bring the entire bed to a perfect plane....

    Cheers,
    IW

  13. #132
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default

    Quote Originally Posted by Simplicity View Post
    Rob,
    I think I missed something here?
    Have you flattened the back of plane iron, then used that to reference(blueing)the blade bed for scraping??.

    Cheers Matt
    Matt,

    Yes, the bottom side of the iron is lapped, coated with spotting compound and then inserted into the plane.

    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. #133
    Join Date
    Dec 2013
    Location
    San Antonio, Texas, USA
    Posts
    3,070

    Default

    Ian,

    Yes, I thought about that too while scraping the bed.

    When I started the blade was bearing on the right near the mouth and toward the bed. On the left it was resting on a ridge left over from machining and in the back it was resting on the two pads on either side of the adjuster slot. It wasn't touching at all across the lip of the mouth with the exception of the spot on the right.

    This plane body is very easy to scrape, especially with a carbide scraper, so if it turns out I've degraded the performance I can always change the bed to suit.

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

  15. #134
    Join Date
    Nov 2011
    Location
    Melbourne
    Posts
    6,973

    Default

    Quote Originally Posted by rob streeper View Post
    Matt,

    Yes, the bottom side of the iron is lapped, coated with spotting compound and then inserted into the plane.

    Cheers,
    Rob
    Ye well like I knew that anyway
    [emoji23][emoji23].

    Thanks for confirming Rob an please ignore the childish inner child [emoji849]

  16. #135
    Join Date
    Nov 2011
    Location
    Melbourne
    Posts
    6,973

    Default

    Quote Originally Posted by rob streeper View Post
    Ian,

    Yes, I thought about that too while scraping the bed.

    When I started the blade was bearing on the right near the mouth and toward the bed. On the left it was resting on a ridge left over from machining and in the back it was resting on the two pads on either side of the adjuster slot. It wasn't touching at all across the lip of the mouth with the exception of the spot on the right.

    This plane body is very easy to scrape, especially with a carbide scraper, so if it turns out I've degraded the performance I can always change the bed to suit.

    Cheers,
    Rob
    Rob,
    I’m starting too develop, possibly a un healthy interest in having a go at scrapping a plane body.
    Not sure whether to Thank you or detest you [emoji849].

    Cheers Matt,

Page 9 of 12 FirstFirst ... 456789101112 LastLast

Similar Threads

  1. Flattening the sole on an old Stanley 5 & 1/2
    By seanz in forum HAND TOOLS - UNPOWERED
    Replies: 9
    Last Post: 13th October 2013, 12:32 PM
  2. Flattening a No.7 sole
    By kman-oz in forum HOMEMADE TOOLS AND JIGS ETC.
    Replies: 15
    Last Post: 29th June 2009, 01:03 PM
  3. Flattening a sole
    By Lignin in forum HAND TOOLS - UNPOWERED
    Replies: 3
    Last Post: 28th June 2009, 03:48 AM
  4. flattening a plane sole
    By mic-d in forum HAND TOOLS - UNPOWERED
    Replies: 35
    Last Post: 26th February 2009, 08:15 PM
  5. Question re flattening plane sole
    By JTonks in forum HAND TOOLS - UNPOWERED
    Replies: 9
    Last Post: 27th June 2005, 10:39 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
  •