Make bow saw for resawing?

[Mark AJ Allen]

I have built my kerfing plane to give a 3/4"-1" depth ... it's enough to hold the saw upright in the kerf square to the surface. I tried deeper but I didn't like feeling/geometry;

[Steve Voigt]

If you want, I can elaborate on the points and how I came to my conclusions. My primary source of sawplate and hardware is From Blackburn Tools.

Great points in your post above Mark; I'd love to hear you elaborate on any or all of it. I'd also love to see some pictures if you feel like it.

I recently had the good fortune to see Don Williams' workshop. He had a couple of original 19th c. veneer saws. One looked just like the Roubo illustrations, the other had short turned handles. I haven't seen any of the modern makers do that, but it makes sense to me. Both saws had very wide plates. As you suggest in (4) above, that's important; I suspect the main problem Adam (and others) had was caused by using a narrow 2" blade. I guess it is possible to get a blade like that to work, but it requires a great deal of skill. It seems like folks using 4" plates have more success.

[Warren Mickley]

sted this picture earlier in this thread.
Attachment 335733
As I mentioned when I posted, this drawing was from Roubo, not Diderot. Andre Roubo was a woodworker, not a philosopher. When I first saw this plate in 1973 I thought the engraver was more used to drawing dancers than woodworkers. However, over the years I have come to think that craftsmen in 1760 actually carried themselves quite differently than today and that they might actually have looked like this. And in fact I now realize that this is one of the plates that Andre Roubo, master woodworker, engraved himself, which I think adds a lot to the accuracy. It is not an "artist's interpretation", it is a woodworkers interpretation.

Here is a plate from Diderot showing a veneer saw being used by ebenistes.
diderot ebeniste atelier.jpg

And lest somebody else suggests that the "shops in Diderot are depicted spotlessly clean", here is Diderot's plate of a furniture shop, menuisier en meubles, showing enough shavings and furniture pieces lying around to give some genuine flavor.
diderot meubles .jpg

I tried putting a preminary kerf around boards to be resawed for some time around 20 years ago. I am kind of foggy about it, but I felt that it was not effective in either saving time or increasing accuracy. In any case I don't think it is a historical method. And in general I am suspicious when someone tries a historical method and reports that it does not work very well. Like some guy fooling in his basement is going to find a better way than the serious 18th century craftsmen.

[Kirby Krieger]

I'd love to hear you elaborate on any or all of it. I'd also love to see some pictures if you feel like it.

Me too . Thanks Mark AJ Allen for your informed, informative post.

[Mel Fulks]

To Warren's comment on the way the workmen in the drawings carried themselves , some of that was from the clothing. I have a friend who has a small collection of clothing from first half of the 18th century. The coats are made so that the shoulders have to be held back to an unnatural degree. The sleeves have more bend it them than modern examples. People affected a public look quite different from passers by today. Might be that the workmen didn't own clothing as nice as the drawings show and were given some good stuff ,in the DRAWINGS for their cooperation.

[Mark AJ Allen]

I love the discussion here; I do lots of resawing and have built all sorts of framesaws and kerfing planes to optimize my resawing technique. I think I'm getting to my really happy place with my experimentation. I could write an essay on the topic but there are some things I would like to add here:

1. Resawing with a frame saw is much more accurate than a hand saw; the plate deflects less because it's under tension
2. Resawing with a pre-established kerf is easier and allows you to correct for deflection easier with a low angle position
3. It is optimal if the kerf width equals the kerf of your resaw; if the kerf is narrow, your saw won't fit. if the kerf is too wide, it lets the saw wander more.
4. A wider sawplate is desirable on the framesaw to minimize deflection; it has more beam strength
5. Length of the framesaw plate; at least twice the width of the cut you're making + 6"
6. I found the traditional design like you see in Roubo unbalanced for single person operation; there is too much weight past the beginning of the cut and the saw digs in. I added an extended handle frame to address that on my design
7. Kerfing with a traditional saw tooth pattern is not ideal; the gullets clog very quickly. A skip tooth pattern better; the plate I have has every other tooth removed. Those still clog, but not as often
8. A one-person framesaw has to be heavy enough to apply ALL the necessary downward force so it cuts without any additional downward force from the operator; you can change that with handle configurations or just add weight

If you want, I can elaborate on the points and how I came to my conclusions. My primary source of sawplate and hardware is From Blackburn Tools.

Seems more interest in how I came to these conclusions . One thing to establish; when I refer to 'good' resawing, I'm talking about minimal deflection from the intended sawing plane; poor resaw require some cleanup with a scrub plane while a good resaw, I can go right to smoothing. Speed is not a factor to me; it takes me about 1 hour to resaw a 10" wide cherry board that's 7' long.

1. As best as I could, maintained the same conditions and did 'resaw-off' experiment using a 3 TPI 28" handsaw and my frame saw on opposite ends of the board. Rip saw was not as good a resaw as the framesaw. No pictures of the results
2. This is one is self evident to me; just as you scribe a line and chisel out a small groove to start a tenon or a dado, the kerf is your starting point. You don't NEED it, but it significantly aids the user's ability to cut straight, to the line. This is only more important because the number of strokes to make a cut is orders of magnitude than a tenon or dado. My practical experience to arrive at this conclusion is attempting to resaw a board without a kerf, then with a kerf; even if you manage to start your cuts without the kerf, the effect of the tension in the wood will affect the deflection of the saw. In otherwords, only in the most straight grained pieces allow you to get away with 'good resawing' without a kerf or a framesaw.
3. I think that is self explanatory. if I can't fit my saw in the kerf, it's useless for guiding my saw. the wide kerf is a little elusive. Back to the scribe line for tenons The groove is intended to guide the saw in the cut, square to the board face and perpendicular to the board edge ... 2 dimensions. if your groove is too wide, it doesn't do that as well. Same with the kerf. If you try to kerf with a plow plane or a table saw, it helps, but there is still lots of potential for slop. Ideal is to have the kerf = resaw width.
4. This is why resawing blades for bandsaws are wider than ripping ones. If the beam strength is higher, the beam is less likely to deflect under a load between two fixed points. It probably also lends itself highly to why framesaw > handsaw for resawing.
5. This is just a practical thing; you don't want the hardware of your framesaw to be slamming on your boards. I specify width of CUT vs. width of BOARD because you aren't always cutting perpendicular to the length of the board. In fact, I recommend against that approach. I think it's best to have as much of the blade in the cut as possible for improved guidance.
6. Hard to explain without a picture of the frame saw I've made. I will add later
7. I think this one is obvious. Where do the chips go if the saw can't eject them? The cutting teeth are in the cut for a relatively long time.
8. You will tire very fast if you have to apply the downward force needed to cut. Perhaps this could be addressed with a more aggressive rake on the teeth on a lighter frame? I can't experiment on that.

[John Kananis]

We made 3 films,actually. There are films that include only ONE of the instruments being made. They are a lot more detailed concerning each instrument,since all the time is devoted to only one instrument. The violin making film is much more artistic.

Unfortunately,the individual films were never made available to the public. They are probably stashed away somewhere in the archives of the Audio Video Department

What a shame, would love to see those.