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  1. #16
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    Hi Rob. That's not how its meant to work. I am only using the loc-tite to permanently adhere the slotted hardback to the top edge of the saw plate. Which means the saw bolt assemblies are still a requirement for the backsaw handle. One of the benefits a slotted hardback has over a folded version is how easy it can be removed up until the decision is made to permanently secure it in position. They are generally machine slotted to a slide fit tolerance. My personal preference, is to wait until the backsaw is ready for the final task of filing and setting the saw teeth before I permanently secure the hardback.

    regards Stewie;

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  3. #17
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    Quote Originally Posted by planemaker View Post
    Hi Rob. That's not how its meant to work. I am only using the loc-tite to permanently adhere the slotted hardback to the top edge of the saw plate. Which means the saw bolt assemblies are still a requirement for the backsaw handle. One of the benefits a slotted hardback has over a folded version is how easy it can be removed up until the decision is made to permanently secure it in position. They are generally machine slotted to a slide fit tolerance. My personal preference, is to wait until the backsaw is ready for the final task of filing and setting the saw teeth before I permanently secure the hardback.

    regards Stewie;
    Given the theme of the thread I misunderstood your post as implying that you glued your backs to your handles in addition to gluing the blades to the backs.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  4. #18
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    Quote Originally Posted by rob streeper View Post
    I like the tight slots too.
    Don't we all!!

    I gotta say I agree with pretty much all the comments above, although it did take some concentration to digest all of Rons detailed post.

    When considering the fit on old saws you have to allow for wear, compression, rust binding, misuses etc. All these things may give false readings in tight or loose fitting scenarios. To me anything that doesn't look deliberate or meant to be always feels a lower quality. So if it looks over cut mortice or blade slot then I get the impression of sloppy workmanship. If the blade slot is going to extend then it should finish inline with some other detail or element so it looks deliberate not just some random distance.

    My own saws bug me for some of these points
    …..Live a Quiet Life & Work with your Hands

  5. #19
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    For some reason I missed this thread 'til today - must need better specs!

    I don't think it makes a lot of difference to function if the spline slot in the handle is loose or tight, for saws using plate of about 20 thou or thicker. As has been mentioned, many old saws are decidedly sloppy, but seem to work just fine if all else is up to scratch. However, pride dictates I do my darndest to get a neat fit when making a saw. Like RayG, occasionally I get it close to perfect. However, my penchant for working with some pretty unforgiving woods means there are nearly always a few tiny blemishes (fiddleback figure is usually the worst, it loves to shed little bits from those curls, along an otherwise perfect edge!). Probably very few people other than the maker would notice, but they bug me!

    I think a firm, and even fit of spline to plate is important, otherwise you may have a lot of trouble getting a straight saw blade. Too loose and much of the stiffening function will be lost. As an amateur, slotting my backs is the easiest & safest route, I don't think I could ever manage the skill required to bend a truly straight back that would grip evenly along its whole length. My preferred fitting method is to cut the slot to a sliding fit & pinch it a little in a vise to get the desired firmness. Using loctite seems like an admission of failure, to me, but it's probably a very sensible & pragmatic way to go, in truth. Pinching in the vise is a bit fraught, and it's easy to overdo it & end up too tight.

    One of the problems I've had, a few times, is a slightly bellied blade slot in the handle. The area where the bolts tighten down has to be planar, or when you tighten up the bolts on final assembly, you find there's a small bow at the end of the blade. Took me a while to figure out what was causing it, but eventually the light dawned that there was a slight belly in the blade slot (the bow went away when I loosened the bolts). I've had a couple of handles with this defect, so I now take great pains to saw a dead-straight kerf for that blade slot! It's not unique to me, I've noticed - a few old commercial saws that have the same problem. It doesn't really affect function, as it is only the very heel of the saw that bends a bit, but it doesn't look good!

    Cheers,
    IW

  6. #20
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    Hi guys,

    I have been repairing and refurbishing backsaws for a number of years. I've done a lot of them. I've come to the conclusion that the mortise part of the saw design is a flaw and a weak point.

    I'm one of those guys who likes to jump outside that proverbial box and try something totally different. I have made an attempt at changing the design to solve the problems surrounding the mortise.

    I'll try to post a few pictures to show what I've done. Now, don't go crazy on me. Try to focus on the reason for the way I did what I did, not necessarily how it might look to you. It's meant to look and be different. This was my first attempt with a bottom side mortise. I've since done others with some modifications.



    This shows how the back extends into the handle so as to eliminate the need for a slot in the handle for the blade. And also eliminates screwing the handle to only the blade. Instead it is attached to the back.


    Here is what it looks like fully assembled. You can make a handle most any shape you want.


    Most people seem to prefer the traditional look of a backsaw even though, over the years, it's been plagued with the fit of the mortise and screwing the handle to a flexible saw plate.

    Here's another attempt at using this design. With this one, I took it a step farther and made the back out of wood and epoxied it to the blade. I know this is way off in left field, but the idea was to simplify the whole thing and still end up with a saw that cuts just as well as the traditional designs. I put these ideas out there for you to contemplate and perhaps spark some additional ideas for improving the handle to blade situation.


    Here's another one. This one I started with a $10 cheapo Bucks Bros. saw that I bought new at Home Depot.


    This is the Home Depot thing..


    I apologize if these pictures are shocking to you. The thoughts kind of rattle around in my mind until I'm driven to turn them into reality.

  7. #21
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    Thanks for the post Marv, there's plenty to think about in that. I'm not sure if I can get my head around largely unsupported blades of those depths though. Perhaps there will be comments!

    I was also impressed with your marquetry oak table top! I have some oak boards that might be best used in that fashion. Any chance on a thread to show us some construction details there?

  8. #22
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    Hi Marv,

    I like your willingness to question ingrained patterns of design. How do the saws work?

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

  9. #23
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    Design aside Marv they look well made. What you haven't mentioned is the thickness of the blade and how well you found them to work or not.
    …..Live a Quiet Life & Work with your Hands

  10. #24
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    Whether or not you've 'improved' saw function is only part of the story, Marv, at least you are thinking about it & trying to address what you see as shortcomings in traditional design. Mucking about & having some fun is the main game for an amateur saw maker, imo.

    I can't see why building a saw like you've done wouldn't work, though as burraboy suggests, the blade depth might be a factor to consider, a little moreso than with a traditional handle, but that's just a guess. You should conduct a few tests with blindfolded users, & see if any can tell whether they are using a conventional handle, or one of yours. (I suspect few will...)

    My thinking is that part of the reason for attaching backsaw handles in the 'traditional' style would be simply convenience, and partly to get the handle in the 'right' position for comfortable & ergonomic use. As long as your handles are well-positioned, the stresses on the saw plate should be similar. One of the problems I've had with traditional attachments, is that if the kerf and/or spine slots aren't done very accurately, tightening down the saw bolts can put a small curve in the heel of the saw plate (I sometimes wonder if this is why spline rebates are so loose on many manufactured saws). Attaching via the spine alone should solve that.

    Cheers,
    IW

  11. #25
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    I'm glad that the conversation on this thread has become more technical.

    I can see both advantages and disadvantages to seating the saw back rigidly in the handle, some of which have been mentioned already but that bear summary.

    1) Rigid or close fit mounting makes for better directional control of the tooth line, particularly with thin blades.

    2) Rigid mounting helps support the saw blade, particularly thin blades reducing their tendency to flex in use.

    3) Rigid mounting may reduce wear to the blade slot of the handle and the screws by limiting the movement of the blade in the blade slot.

    4) Rigid mounting allows the handle to be cast right or left relative to the tooth line.

    5) Rigid mounting looks better and is considered to represent a higher level of craftsmanship.

    And some disadvantages such as.

    1) Rigid mounting increases the likelihood of breaking out the sides of the back mortise in the event that the saw is severely flexed.

    2) Rigid mounting is somewhat more difficult to do well. Mistakes in mortising stand out.

    3) Rigid mounting causes deflection of the tooth line when the back mortise and blade slot are not perfectly aligned. Aside from manufacturing mistakes such an effect may be induced by warping of the handle due to age or changes in moisture levels.

    Overall, I think that the benefits outweigh the disadvantages. I have never seen a backsaw with a broken mortise and I have never broken the mortise of any of the saws I have made despite using the saws with deliberate aggression to test their robustness.
    I have purposely mounted a backed blade in a handle with too large a mortise and found that the flexibility of the blade and the mass of the back tend to cause the blade to run off-line.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  12. #26
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    Quote Originally Posted by burraboy View Post
    Thanks for the post Marv, there's plenty to think about in that. I'm not sure if I can get my head around largely unsupported blades of those depths though. Perhaps there will be comments!

    I was also impressed with your marquetry oak table top! I have some oak boards that might be best used in that fashion. Any chance on a thread to show us some construction details there?
    The blade thickness is .025. What we think of as a "supported" blade is only supported at the heel end and usually not the full depth of the blade. The toe end is always unsupported in that sense. When using the saw, I do not detect any deflection of the blade due to not being screwed to the handle.

    The marquetry oak table is not my work. We bought the table at a furniture store many years ago. It sometimes works well for a background for taking pictures of wood.

  13. #27
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    Quote Originally Posted by rob streeper View Post
    Hi Marv,

    I like your willingness to question ingrained patterns of design. How do the saws work?

    Cheers,
    Rob
    Hi Rob,

    In my hands, the saws function as well as any other well fitted handle to a back. However, I can clamp any backsaw with a top mortise in a vise by clamping only on the back and be able to move the handle side to side at least to some degree depending on how tight the back fits the mortise. With my bottom mortise design and the handle bolted only to the back, I can do the same test and not have any side to side flexing. The back I have on the first saw is 1/4" x 3/4" steel with a milled slot and pressed onto the blade.

    The second saw has a wood back that is 1/4" x 1" well seasoned black walnut with the blade epoxied in the slot and into a slot in the handle. The stiffness of the blade using the wood back and epoxied to the blade is surprisingly stiff and inflexible. With the blade attached in that manner, I was quite surprised to be able to thimp the blade and get a ring from it. I have never been able to do that with any other backsaw. Not that, that is important. It's was just unexpected.

  14. #28
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    Quote Originally Posted by IanW View Post
    Whether or not you've 'improved' saw function is only part of the story, Marv, at least you are thinking about it & trying to address what you see as shortcomings in traditional design. Mucking about & having some fun is the main game for an amateur saw maker, imo.

    I can't see why building a saw like you've done wouldn't work, though as burraboy suggests, the blade depth might be a factor to consider, a little moreso than with a traditional handle, but that's just a guess. You should conduct a few tests with blindfolded users, & see if any can tell whether they are using a conventional handle, or one of yours. (I suspect few will...)

    My thinking is that part of the reason for attaching backsaw handles in the 'traditional' style would be simply convenience, and partly to get the handle in the 'right' position for comfortable & ergonomic use. As long as your handles are well-positioned, the stresses on the saw plate should be similar. One of the problems I've had with traditional attachments, is that if the kerf and/or spine slots aren't done very accurately, tightening down the saw bolts can put a small curve in the heel of the saw plate (I sometimes wonder if this is why spline rebates are so loose on many manufactured saws). Attaching via the spine alone should solve that.

    Cheers,
    Hi Ian,

    The thickness versus the amount of blade below the back is always a serious consideration. The handle design and the method of attaching it to the blade is mainly what the experiment was for with these saws. Over the years I have repaired many old backsaws for customers that were either cracked or pieces broken off. The title of this thread pertains to how tight should a top mortise be, tight, snug, or loose. With my design, all of these concerns become moot. My thinking was, the back is kind of the backbone of the saw, so why not allow it to also support the handle as well. At the same time, simplify the making of the saw by eliminating drilling the blade and matching the holes to the handle and slotting the handle. With the wood back saw, even the screws are eliminated. And the back can be done by most any woodworker. I made the back and the handle two pieces, but it could be done with only one piece if the wood is stable enough.

    It is apparent, from the lack of interest I get from people I show these ideas to, most people are stuck on the traditional look of a backsaw. Drastic change is difficult for a lot of people. I fully understand that. After all, we are all individuals with our own preferences. Sometimes though, it can be interesting to at least ponder something new, especially if it is an improvement. Lee Valley has been quite successful with their New Concept backsaws. However, the average woodworker can't make backsaws like theirs. But they can do what I did.

  15. #29
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    Quote Originally Posted by MarvW View Post
    Hi Rob,

    In my hands, the saws function as well as any other well fitted handle to a back. However, I can clamp any backsaw with a top mortise in a vise by clamping only on the back and be able to move the handle side to side at least to some degree depending on how tight the back fits the mortise. With my bottom mortise design and the handle bolted only to the back, I can do the same test and not have any side to side flexing. The back I have on the first saw is 1/4" x 3/4" steel with a milled slot and pressed onto the blade.

    The second saw has a wood back that is 1/4" x 1" well seasoned black walnut with the blade epoxied in the slot and into a slot in the handle. The stiffness of the blade using the wood back and epoxied to the blade is surprisingly stiff and inflexible. With the blade attached in that manner, I was quite surprised to be able to thimp the blade and get a ring from it. I have never been able to do that with any other backsaw. Not that, that is important. It's was just unexpected.
    The lesson I'm taking from this is that supporting the back well is the key issue. Unless the blade is tall and or thin supporting the blade doesn't matter as much. Witness gentleman's saws and the ancient cane handled saws http://www.wkfinetools.com/hUS-saws/...8thCentSaw.asp.

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

  16. #30
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    Quote Originally Posted by rob streeper View Post
    The lesson I'm taking from this is that supporting the back well is the key issue. Unless the blade is tall and or thin supporting the blade doesn't matter as much. Witness gentleman's saws and the ancient cane handled saws http://www.wkfinetools.com/hUS-saws/...8thCentSaw.asp.

    Leaves a lot of design latitude...
    Rob,

    Using the Gents saw for comparison does a good job of putting it in perspective. Change the handle from a broom stick to a handle with a grip hole and you have something that closely resembles my bottom mortised design.

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