Thread: Handsaw hang angles.

Hi Derek. Would it not be advantageous to adopt a singular method that not only serves to provide you with an answer to the hang angle, but also provides you detail on the directional force being applied to the tooth line. By adopting the tooth line within its formula as seen within Issac's method, changes within the directional force resulting from a canted saw plate can be accounted for.

regards Stewie;

Originally Posted by planemaker

Hi Rob. View the following as a suggestion only, and not a criticism of your recent mention on how the hang angle should be best measured.

If a single method of measuring the hang angle was deemed necessary, I would prefer to adopt Isaac's method of utilizing the tooth line. With 1 slight change. Where Isaac has the directional force line intersecting at 90* from the middle span of the handle grip, I would prefer that line intersect where the thumb and forefinger webbing makes contact with the outer grip. http://www.blackburntools.com/blog/w...-saws-hang.gif

Stewie;

That's my intention.

On my recent mitre saw (in a mitre box), with a 16" long plate, the hang angle was 23 degrees. This encourages more of horizontal push, which is wanted in a mitre box, where downforce is unnecessary. 23 degrees is also recognised by some, such as Isaac, for tenon saws generally ... regardless of length?

Hi Derek. Are you sure your correct with that statement.

regards Stewie;

[QUOTE=planemaker;1902734]On my recent mitre saw (in a mitre box), with a 16" long plate, the hang angle was 23 degrees. This encourages more of horizontal push, which is wanted in a mitre box, where downforce is unnecessary. 23 degrees is also recognised by some, such as Isaac, for tenon saws generally ... regardless of length?

Hi Derek. Are you sure your correct with that statement.


Hi everyone. Sorry I have once again missed the bulk of the discussion.
I have been reading this thread when time allows, ( Putting on a roof lately so no time. ) There are several things I noticed that I may not agree with completely. But more so that I do. Just some rambling thoughts. My apologies if I state the obvious.
1st. Thank you to Derek for posting. Particularly for showing me another picture of the wonderful little miter box and saw you made. Feel free to send it to me when you tire of it. I do like the Groves saws as well. Anyway, Derek and others have pointed out very clearly why one's personal mechanics, as well as length and intended use, are paramount to determining the appropriate hang angle for a saw. At least a custom saw. Production saw makers will no doubt settle for the middle of the road to serve the greatest percentage of customers. No differently than hand size.
2nd. I do not put dovetail saws in the same exact category as tenon saws. One should be careful to not put all saws in the same category when seeking methods for determining hang angles. Hand saws and panel saws must absolutely take into consideration the grip height relative to the plate height. Hand and panel saws are certainly different animals with their own constraints in design and use.
Joinery saws, depending on many factors such as bench height, using a moxon vise or not, overall personal height,( pivot points ), and of course whether one likes to stand over their work or stand back a bit, all comes into play. Imagine, if you will, once upon a time, numerous workers in a "factory" all working at the same benches at the same bench height. Were all the workers the same height with the same mechanics? I doubt it. But, they may all very well have had their own personal saws, made to their preference, including hang angles. Sharpened to their preference to best suit their mechanics/ needs. Even if they were not, I would be willing to bet they had their favorites they tried to get each day. More of a behavioral component based on comfort level with a particular tool and preference. I can't help wonder if the owners had shorter benches for the shorter guys and taller benches for the taller guys. Perhaps in a small shop. There is a reason some one invented the moxon vise other than bench height, no doubt. Imagine the reaction those workers, many of whom were masters in their own right, would have had if one of our modern day writers had told them they were not doing it correctly because they did not do it "my way" or like the picture in a book showed. Indeed there are just too many variables to make any assumption of what is the best hang angle or what should be the standard. There are, I think, general guide lines with plate length vs hang angle being one of them, but I doubt there were any standardized formulas for determining the hang angle vs the plate height ratio. More than likely, in my opinion, just some accepted guidelines through trial and error over time and passed on from one to another based on feed back from the buyers. Many of whom, no doubt, worked in the factories such as Disston's.
3rd) I should point out that Issac's method is spot on when determining hang angle, in my view. Regardless of where the actual resultant vector passes through the handle. I often draw mine through the center of the hump just out of convenience. The angle is still the same. Of course, since I also use that method, I may be biased. "Hiroller's" is basically the same. The hang angle should be determined, in my opinion, based on grip angle vs tooth line. Using any other "formula" may lead to false results. Example: The cant of a tooth line affects the downward force of a saw directly as well as the visual reference line. Altering the folded back angle does nothing except alter the visual reference. ( I have seen numerous examples of folks mistakenly believing a saw is canted because the toe end of the back was tapped down ) I see no need to address pitch, rake and fleam, because they do nothing but fine tune the hang angle of any given saw. This is not to say those variables can not make or break the functionality of a saw. But these can be very individualized preferences or task specific and can be changed. If you don't like how it cuts, refile it.
4th) Obviously, the lower the hang angle the greater the distance, from the neck of the saw to the actual force being applied. Hence you may have noticed lower hang dove tail saws, for example, have a thicker ( front to back ) neck area to compensate for the increase in the moment about that axis. ( force times distance )( I hope I said that correctly as it has been a while. ) There is no way, in my opinion, to accurately calculate the needed volume of the neck area, other than perhaps averages, as different woods have different shearing strengths, as well as muscle bound monkeys that think every saw is a hand saw and you should plow through a cut as fast as possible. Hand planes are no different than saws in that, given the grain direction, too much force at the top of the plane tote will shear the tote in two, despite the long steel bolt passed through it. The saw is just the opposite. Too much force at the bottom could shear an open handle tote. A closed handle, of course, transfers the force being exerted on the tote to the cheek, preventing the shearing. Indeed the lamb's tongue was born out of function and made to be attractive by the craftsman like every thing else back then.
Lastly, my personal mechanics has me applying a resultant force ( resultant thrust vector ) closer to the neck/ web of my hand, rather than the center of the grip on my 45* hang dovetail, but slightly lower on my 38* dovetail. If I were to use a moxon vise with the work being higher, I would no doubt prefer my 32* dovetail due to my height relative to the work. So I think all things are relative, within reasonable limits, and no wonder there are so many different hang angles on joinery saws. Lest we drive ourselves crazy searching for absolutes. Sorry if I rambled a bit. It's late. Best wishes.

Hi Ron. Appreciate the time taken to forward your thoughts. Excellent value.

regards Stewie;

Originally Posted by planemaker

Hi Ron. Appreciate the time taken to forward your thoughts. Excellent value.

regards Stewie;

Good morning. Now that I am awake I did indeed ramble a bit. Oddly, I left out a little bit.
Miter saws, for the most part, fall outside of this comparison because the vertical weight is supported by both the wood being cut and the guide to some extent. While the "Z" axis is supported by the guide rods as well. Again, what ever the hang angle, within reason; the pitch rake and fleam can fine tune, leaving the arm to act only as a crank shaft driving the piston back and forth.
Also, if we draw a stick figure of a person and just draw the pivot points, hips, knees, shoulders, elbows, and wrist relative to a given point to represent the work piece being cut; we can more clearly see the need to consider the point of the grip center/ hump as a reference point for both balance and stroke force. Having a grip height too high diminishes the ability of the triceps / upper arm to push forward. Leaving the rotational strength of the shoulder to drive the stroke as well as putting the wrist in a some what unnatural position. And back to ergonomics we go. A mechanical engineer would no doubt be able to show this better graphically. Best wishes.

Hi Ron,

Thanks for taking the time to post.
Nicely put.