Thread: Spear and Jackson rip saw

I think that a somewhat accepted geometry for aggressive ripping would be 7-9deg rake with 3-4.5 tpi pitch.

In other words, assuming the angles in your drawing are somewhat accurate, that's filed more like the geometry of an aggressive crosscut saw. If the direction of cut in that image was left to right, you would want the teeth to be leaning more toward the right, with the angle between the point and the bottom of the gullet (the rake angle) at around 7-9deg.

Hope that helps (and, more importantly I hope the info is right).

Cheers,
Luke

Great explanation from Isaac here: Blackburn Tools - saw tooth geometry
Rake for rip saws
0-6 degrees for softwoods
6-12 degrees for hardwoods

For construction saws 4^o was used for rip and 8^o for crosscut. For modern handsaws, applied as they usually are to the creation of items like furniture, 8^o for rip and 12-15^o for crosscut works better for most people, particularly in harder wood species. Depending on the saw and the intended use I've used 15^o rip and 20+^o crosscut in certain situations such as saws having extreme hang angles.

I would add another vote for something between five and ten degrees of rake to start. Whatever you work in, let that decide after that if you're too aggressive (sticky starting and resistive sawing) or not aggressive enough (a cut that doesn't feel like it's severing fibers without you leaning on the saw).

If you start too aggressive, it's very easy to kiss a tiny bit of extra rake onto the saw with the pass of a file. If you start not aggressive enough, then you'll need to file back the whole tooth face to get a more aggressive tooth (which isn't that much work, either, I guess).

Personally I'd suggest you try out something filed at 0 degrees rake at some stage.
Given that power tools are a definite possibility for all of us, I think sawing should go as quickly and easily as possible to give points in favour of the hand-tool option.

I've used zero rake ripsaws for both ripping and crosscutting and have only seen (varyingly) reduced cutting ability from other setups. I don't dismiss the 'rules of thumb' lightly - there's probably reasons for it ... I just don't know what they are.


By the way, I posted some WIP a while back about turning some teeth like yours into a strong ripsaw.
It took a lot of height off the current teeth - that in particular was the bit I hadn't figured out ahead of time and was surprised by.

Ripsaw Sharpening - (or Trial and error in the 'burbs)

Cheers,
Paul

My mistake. One saw was a S&J that looked like:


but the one I spent time on was in a reasonable ripsaw rake ... ... but the toothline was hollow.

Originally Posted by pmcgee

Personally I'd suggest you try out something filed at 0 degrees rake at some stage.
Given that power tools are a definite possibility for all of us, I think sawing should go as quickly and easily as possible to give points in favour of the hand-tool option.

I've used zero rake ripsaws for both ripping and crosscutting and have only seen (varyingly) reduced cutting ability from other setups. I don't dismiss the 'rules of thumb' lightly - there's probably reasons for it ... I just don't know what they are.
.....

Paul, I've said this before, but you must be a very strong young bloke with a thing for pain! If I were to put zero rake on any of my rip saws I know I'd have a demon of a saw, but the action would be far too rough & ready, and it would be a most uncomfortable saw to use on a bit of Spotted gum (or Jarrah, for that matter!). When I first sharpened a big progressive (3-5tpi) ripsaw, I didn't watch the rake angles and they crept forward 'til they got very close to zero over several sharpenings. The saw didn't cut any faster, but it certainly became very unpleasant to use.

Those old geezers like my dad who had to use meat & potato-powered saws every day figured out what they thought was the best set of compromises for their tools, and funnily enough, they usually came up with similar specifications and rules of thumb, with 5-7 degrees rake for our hardwoods being one of them. That's far more comfortable in any of our hardwoods, & you will particularly notice it when you have to bring the saw down to straight across the grain, as when finishing a cut up to an edge, etc. A ripsaw with negative rake should still cut quickly but smoothly.

I never met anyone who used zero or positive rake on a hand-powered ripsaw (as opposed to bandsaws, for e.g.), but perhaps there were a few big strong fellas who relished the pain, so I wouldn't say no-one ever did it before you.....

Cheers,

Well by tomorrow night, one way or the other I will have a rip saw or a headache. I will start with 5 degrees and see how I go. At present, the rake angle must be at least 30 degrees and the thing does not cut at all. I bought it tp play games with so I have nothing to lose and skill to gain.

Hi IanW.

I don't see strength as a part of it ... I don't think it's about "muscling through" a cut ... just getting the most "rip for your buck" as it were. I am interested to hear from anyone about their experiences with whatever rake they are using.

I was nodding my head when I read the old Tage Frid article about using (framed) ripsaws only - but I'd already been developing a bias in that direction on my own.

The most difficult thing to crosscut was a "stringy" wood like oregon pine, that has the distinct softer and harder strings. The hardwoods I have here are pretty uniform and have no real trouble cutting in whatever direction.

I think it teaches you to lift the weight of the saw up off the teeth and skim when it is required, and I think that's a good thing.

I had posted this video in the thread about making my (experimental, I guess) jarrah-lump saw vice.
It's a 8 or 10 point zero rake ripsaw crosscutting the end off of two jarrah boards - about 90mm total.

This cut was perfectly fine for speed, but I'd like people to be thinking that, in addition to doing it moderately carefully in 2 minutes, with a 5ppi saw they could have this off in maybe 1 minute and 20-30 strokes**.



I've also posted a picture before of a 6" x 2" piece of hardwood that I'd crosscut with a 5ppi ripsaw, leaving a pretty glossy surface (from some angles), by cutting flat across like a mitre saw.

Granted an actual crosscut-filed saw should help guard against spelching the far side.

Cheers,
Paul

** ok not 20-30. I counted the video at about 200 strokes (short strokes, because the brick wall behind was cramping the freedom to move freely).
But half the time anyway, I'd guess.

Hmmm, not a very good yardstick, P1. As you point out, your cramped situation is forcing you to use barely half the blade and a choppy stroke, so I wouldn't use it as a yardstick! I couldn't predict how many strokes it would've taken me to cut through those boards with one of my (crosscut) saws, considerably fewer than 200 if I could use the whole saw, but probably more than 20!

I take your point that technique has a lot to do with sawing, and also that you can cut just about any wood with just about any saw whatever its configuration. However, I maintain that it's a heck of a lot easier both in terms of effort & following your line, to do it with a saw that's configured for the type of cut. Of course you can crosscut with 'rip' teeth, and even get a decent surface, though there is likely to be more spelching, as you admit, which may or may not matter. However, I'll bet London to a brick you would do it both easier, cleaner & quicker with a well-sharpened crosscut of equal tpi. Your observation that a rip saw struggled with cross-cutting Oregon can be translated into pretty near all softwoods and any wood with high moisture content, but even dry hardwoods should cut better, easier, & quicker with a well-tuned crosscut saw. Believe me, I'm all for the easiest way to get from A to B; sharpening crosscuts is harder to learn (well it was for me) and it takes me twice as long to sharpen a crosscut. If it weren't worth the effort, you can be sure the practice would not have persisted as long as it has.

I was teasing you about being young and strong but I still think whatever your age & degree of fitness, you would notice a huge difference in the number of calories it takes to rip, say a 1.8 metre, 45mm thick hardwood board with appropriately-raked, well-sharpened teeth vs overly-aggressive ones. But each to his or her own, and situations vary. I'm quite happy to use the "all-purpose" hard-point I carry around in my ute when it's all I've got, and it does a surprisingly good job, but when I'm at home and have the choice of a saw that's more tailored to specific tasks, the hard-point stays in the ute....

Cheers,

I have a Stanley hard point saw that I bought last weekend from Mitre 10 for $16.it is nice saw. Plastic handle and all. But if I ever had to rip 1.8 of balsa wood I wood reach for something plugged into the wall. I am very lazy.

P2 here.

What did I start when I coined that monicker to differentiate between pmcgee and Bushmiller?

Chook. There is the theoretical angle and the angle in practice The theory is that a rip saw tooth is filed at 90 deg. That is the cutting face of the tooth is vertical. In a rip saw it acts like 156 little chisels (in a 26" 6ppi saw). all taking out a slither. However, a saw sharpened like this bucks and and is quite difficult to operate. If you like, the teeth are digging in because you can't generate enough speed. As others have said a range of anything between 5 deg negative rake and 10 deg negative rake would be the normal range.

If you had two rip saws, you could sharpen one at 4/5 degs for softwood and the other at 7/8 degs for hardwood. with one saw I would go for the hardwood angle. It will still cut very well in softwood too. As the rake is increased the smoothness of operation increases, but it will eventually reach a point where it is absolutely smooth, but has ceased to cut! So we go with a compromise.

Check your saw's teeth. Some saws have a progressive tooth. This is where the first few inches of saw starting at the toe will have more ppi than the bulk of the saw (more often found on coarse teeth leass than 5 1/2ppi). This is to assist starting the cut. I think this style was phased out once machine sharpening of saws became the norm as the machines could not be set up to cope with this.

Starting the cut with a rip saw is more difficult than with a crosscut saw. Drawing the saw back three or four times doesn't work well as the back of a rip tooth is blunt. Start a rip cut pushing forward with the saw almost horizontal on the wood as you need at least four teeth in contact with timber.

We'll look forward to seeing the saw all sharpened up and hearing how you went.

Regards
Paul

Originally Posted by IanW

I'll bet London to a brick you would do it both easier, cleaner & quicker with a well-sharpened crosscut of equal tpi.

The xcut vs rip discussion is a different one to the one regarding degrees of rip rake, obviously.
I'm sure you're right about "of equal tpi" (... except I'm also wondering if maybe rip teeth could be inherently better shifters of material than a set of xcut teeth).
But you generally don't have a 5ppi xcut saw. Looking in the old catalogues that specified the ranges of point-sizes available for each model and length of saw, 5 and 6 ppi xcuts were unusual.

So, in the interest of encouraging more people to grab a first saw or saws, ...
- ripsaws are the easiest to sharpen,
- they are findable from 4ppi to 12ppi in handsaws,
- they can rip and crosscut,
- you can use a finer tooth for a finer cut,
- and if you want to get fancy, by sloping the gullet, you can have a zero rake AND a pointed (non-flat) tooth.

My "unimportant challenge of the month" would be:
at some time, try cutting only with a 5ppi ripsaw for a week (6ppi to take the easy road).
Getting it to work will be instructive for all cutting, IMHO.


Cheers,
Paul

Paul

I not totally convinced by your rip saws for crosscutting. I think, if they were better performers, they would have used them for the Docking saws, which were 4 1/2ppi in crosscut configuration. I'm pretty certain you have at least one of those so you might be able to do a comparison. I did make up some coarse crosscut saws recently for two customers, but I don't have them any more.

This is one of them. I think it was 5 1/2ppi.

Disston D8 Big Fangs 023.jpgDisston D8 Big Fangs 017.jpg

Regards
Paul

Originally Posted by Bushmiller

4 1/2ppi in crosscut configuration

That'd do it.