Handsaw hang angles.

[planemaker]

The fact that there is no historical reference to the use of a mathematical formula to measure the hang angle to high level of accuracy may suggest no formula was deemed necessary by early saw makers. Possibly, saw makers of that era simply relied on the more basic technique of lining up the extended index finger to a point along the tooth line that was deemed highly functional for that type or size of backsaw. That the point along the tooth, was not some agreed value by all saw makers of that era, but likely an individual judgement based upon each saw makers prior learning and/or experience. The fact that early era backsaws fitted with the same dimensional saw plate do show a wide range of variation within their handle hang may add weight to that theory. If we move forward in time to that of the modern era saw makers and quiz them in search of an agreed consensus to where along the tooth line that index finger should point on a backsaw of a given dimension, its mostly the feedback received would range from; aligned to the front toe, an inch back from the front toe, 2 inches back from the front toe, center of the saw plate, toe side of center, heel side of center, pointing at the heel, 1 inch forward of the heel, 2 inches forward of the heel. In other words, a lack of agreed consensus.

Stewie;

[planemaker]

Isaac's feedback on the subject of using a formula to determine the hang angle:

admin says: November 9, 2013 at 12:28 am
Andy,
I more or less made all of this up as I went along. Like you, I could find no precise definition or standard, so I took the basic definition and expanded upon it.
I put it at the center of the handle because it felt like a good average. I think the actual location of the force varies from person to person, as well as varying throughout the stroke. It’s really a tough one to pin down, but that seemed like a good compromise, even if somewhat arbitrary.
I intentionally avoided using any numbers for this very reason. It was my intent to show the effects of changing the variables, and using numbers just complicates that, and contributes little to actually understanding the matter.
Using this as a starting point, it should be a fairly trivial matter to vary the angle and point of application of the force to see what happens.
As far as being a saw geek, well, you’re talking to someone who spent more than a few sleepless nights working on these posts. I’m not sure which is worse, but I’m glad to have the company down here… http://www.blackburntools.com/blog/c...d-saw-handles/

[planemaker]

How the hang angle should actually be measured also varies within opinion.

http://www.wkfinetools.com/hUS-saws/...-WMB-No3-2.asp

[rob streeper]

Another factor that hasn't been mentioned here is the differences in how handsaws are used now compared to the 19th and early 20th century.
Then, handsaws were used for all types of woodcutting done outside of a saw mill or shop equipped with machines. Today there are very few handsaw made cuts relative to the total number of cuts. Further the nature of the cuts we now make is largely restricted to furniture joinery or other small scale work. No doubt that there a few people that use handsaws for building houses but they're very atypical.

[planemaker]

Hi Rob. I am not sure I can add much more to the discussion on hang angles. As mentioned earlier, IMO most saw makers are guided by their own unique preference.

Stewie;

[rob streeper]

Hi Rob. I am not sure I can add much more to the discussion on hang angles. As mentioned earlier, IMO most saw makers are guided by their own unique preference.

Stewie;

That's pretty much my perception. This is another important factor in handsaw manufacture that everybody (those who're interested of course) has an opinion on but nobody has seriously analyzed, much like saw plate hardness.

[planemaker]

Hi Rob. To be fair, Isaac has already done some excellent work on this subject. I hold a great deal of respect for Isaac's depth of knowledge within the craft of saw making. His own study on the subject of handle hang is a very good example of his fine work. No different to the work you recently undertook on hardness testing and taper grinding of saw plates.

regards Stewie;

[rob streeper]

Stewie,

True, Isaac has laid out relevant factors and describes their interactions and I don't fault his work in the slightest. However, it doesn't tell us what hang angle, or range of hang angles, is most appropriate for any particular type of work. I'm proposing to study trends in the various parameters, something easily accomplished given the depth of images of older saws available now. As time allows I may also do some empirical work. Fortunately for us all, science is not 'done'.
Another factor that hasn't been discussed is that we're only considering push-to-cut Western type saws. What about Japanese style pull-saws? Their toothlines are set at an angle to the force applied by the sawyer too. What, if any, connections might be found between the angles used on Western and Eastern saws?

Rob

[planemaker]

I am current focused on open handle design; specifically the importance of beam strength through the neck of the handle.

Stewie;

[rob streeper]

Great, I've been thinking about how I might instrument an open handle such that the dynamic forces applied can be measured.

[planemaker]

Hi Rob. My approach is a little less complicated. I am focused more on the shaping of the neck to maximize the benefits continuous long grain can offer.

Stewie;

[rob streeper]

http://www.woodcentral.com/woodworki...-open-handled/

http://www.woodcentral.com/woodworking/forum/archives_handtools.pl/bid/3108/md/read/id/130785/sbj/handsaw-handle-angles-closed-handled/

http://r.search.yahoo.com/_ylt=A0LEV...YO6FqbD5M01W8-

http://www.backsaw.net/index.php?opt...=59&Itemid=103

https://thesawblog.wordpress.com/201...ange-your-saw/

https://books.google.com/books?id=QU8FAgAAQBAJ&pg=PA258&lpg=PA258&dq=backsaw+hang+angle&source=bl&ots=9Xax0fHCaa&sig=to9nuVMaLbjwAmg-2qdSQEkWxh0&hl=en&sa=X&ved=0CFMQ6AEwB2oVChMIxo_LnbKpyAIVi40NCh1f2wYJ#v=onepage&q=backsaw%20hang%20angle&f=false

http://thevalleywoodworker.blogspot....ang-angle.html

[planemaker]

http://www.woodcentral.com/woodworki...-open-handled/
Hang angle range 38 - 55.
http://www.woodcentral.com/woodworki...losed-handled/
hang angle range 54 - 76.

Without knowing the saw plate dimensions, its difficult to make any clear judgement on hang angle trend. IMO

Stewie.

[rob streeper]

These links give an appreciation of what history can teach us if we're willing. I've conceived a design for a variable hang angle / variable h / quick-change blade dovetail saw. Now to get some time to make one up.

[planemaker]

We now have a 3rd method being used to measuring the hang angle. Different methods, different results.

1st.
http://www.woodcentral.com/woodworki...-open-handled/
http://www.woodcentral.com/woodworki...losed-handled/

2nd.
http://www.wkfinetools.com/hUS-saws/...-WMB-No3-2.asp

3rd.
http://www.blackburntools.com/blog/c...d-saw-handles/

Stewie;