Thread: Progressive pitch/rake handsaws

Adam Cherubini ... PWW 2006

PROGRESSIVE FILINGS
A really coarse ripsaw is a joy to use, but a pain to start. You can have an aggressive saw that starts every stroke easily without an iron wrist. The teeth can vary in pitch and rake along the length of the blade. This was common before machines cut sawteeth, and, contrary to popular belief, was absolutely deliberate. Disston varied the pitch on ripsaws such that a 4 tpi ripsaw may have as many as 7-8 tpi at the toe. It was common to vary rake angles as well. Modern saw filers are experimenting with progressive filings in which only rake varies. You could try varying only pitch. In short, there’s no rule that says all a saw’s teeth have to be the same. By varying the shape of the teeth along the edge of the saw you can further optimize the performance of your handsaws. — AC

Originally Posted by pmcgee

Adam Cherubini ... PWW 2006

PROGRESSIVE FILINGS
A really coarse ripsaw is a joy to use, but a pain to start. You can have an aggressive saw that starts every stroke easily without an iron wrist. The teeth can vary in pitch and rake along the length of the blade. This was common before machines cut sawteeth, and, contrary to popular belief, was absolutely deliberate. Disston varied the pitch on ripsaws such that a 4 tpi ripsaw may have as many as 7-8 tpi at the toe. It was common to vary rake angles as well. Modern saw filers are experimenting with progressive filings in which only rake varies. You could try varying only pitch. In short, there’s no rule that says all a saw’s teeth have to be the same. By varying the shape of the teeth along the edge of the saw you can further optimize the performance of your handsaws. — AC

that AC quote seems to align with what i was saying and do. it can be worthwhile on crosscut saws too

That's a very interesting and informative article Paul - thanks for posting it.

Cheers, Brett

Originally Posted by pmcgee

...
The teeth can vary in pitch and rake along the length of the blade. This was common before machines cut sawteeth, and, contrary to popular belief, was absolutely deliberate. Disston varied the pitch on ripsaws such that a 4 tpi ripsaw may have as many as 7-8 tpi at the toe. It was common to vary rake angles as well.

WHAAAAAT... !!... !!!

This is for me one of those revelation "OF COURSE!!!" moments!!! and looking back it makes perfect sense. If a trades/craftsman was sharpening his own tools (and truly new what he was doing) then of course he'd set up his tools to suit his work, and this would include setting up saws to work optimally. I do this, in a perhaps limited way, for chisels and plane blades. As technology and automation has progressed, these variables have disappeared.

TIME WE PUT 'EM BACK

RIGHT! Who can show me how to set up my disston and vickers backsaws with variable pitch, rake and fleam?!?!

OG

Hi Paul,

What FF said. Onya.!!!

Cheers
Pops

Originally Posted by Old gunnie

WHAAAAAT... !!... !!!

This is for me one of those revelation "OF COURSE!!!" moments!!! and looking back it makes perfect sense. If a trades/craftsman was sharpening his own tools (and truly new what he was doing) then of course he'd set up his tools to suit his work, and this would include setting up saws to work optimally. I do this, in a perhaps limited way, for chisels and plane blades. As technology and automation has progressed, these variables have disappeared.

TIME WE PUT 'EM BACK

RIGHT! Who can show me how to set up my disston and vickers backsaws with variable pitch, rake and fleam?!?!

OG

thats what i mentioned doing, that i do for myself!! i dont think i ever referred to myself as a craftsmen though, sounds a bit weird or presumptuous, definitely a chippy and joiner though

fleem is easy to add at any time, rake; wait until next sharpening, extra tpi you loose some steel/depth to the blade, so you have to be sure you want it on an old saw, cant go down to the shop and buy another one too easy

Originally Posted by ch!ppy

... definitely a chippy and joiner though

My old man's a chippy chappy. Thinks fine work is getting the house or shed frame within an inch of square , and just cannot see the use of the three veritas backsaws I have.

He got me to help him sharpen his "big" saw one day. 6' long and .66ppi! Yep, 'bout a tooth per inch 'nd a half. Disston, used for cutting down sequoias or summit. Pretty easy to sharpen tho. Just ran the grinder over each tooth. Simple! Not much good on Jarrah, but worked a treat on CCA pine. Nice little piles of poison on each side of the poles without the clouds of poison produced by the power saw. Quiet too.

Cheers
OG

Originally Posted by ch!ppy

... you loose some steel/depth to the blade, so you have to be sure you want it on an old saw, cant go down to the shop and buy another one too easy.

Yep, agree. Happy to try in one of the 6 or 7 disstons I've got (can't seem to pass 'em up at 5 or 10 bucks each), but p'haps not on the vickers.

Cheers
OG

Originally Posted by Old gunnie

My old man's a chippy chappy. Thinks fine work is getting the house or shed frame within an inch of square , and just cannot see the use of the three veritas backsaws I have.

each to their own, loath to criticise anyone else, whatever works for them is fine with me, but for myself i often cut a roof out before the wall frames are even completed, let alone squared, plumbed and up, so i make sure wall frames are as near to perfect as possible, thats not standard practise, pretty risky too (lots of dollars worth of timber to precut) but i had been doing that way many years before computers ever started to be around and cut roofs, even now computers dont pre-cut roofs to the mm, they leave some space for the carpenter to cut to fit....maybe because i am a qualified/trained joiner as well but i dont think so, its just my nature

Originally Posted by Old gunnie

He got me to help him sharpen his "big" saw one day. 6' long and .66ppi! Yep, 'bout a tooth per inch 'nd a half. Disston, used for cutting down sequoias or summit. Pretty easy to sharpen tho. Just ran the grinder over each tooth. Simple! Not much good on Jarrah, but worked a treat on CCA pine. Nice little piles of poison on each side of the poles without the clouds of poison produced by the power saw. Quiet too.


Cheers
OG

thats just the ticket for that stuff!

chippy

I mentioned that I had been waiting for a good time to watch Ron Herman's DVD on saw sharpening (US$25):

[ame=http://www.youtube.com/watch?v=glaVp5lszmw]Sharpen Your Handsaws with Ron Herman - YouTube[/ame]

I've seen it now (once!) and I like it a lot in the end. The camera-work at the start is a bit awful, but it improves and the information is good.
I'll be watching it plenty more times yet I know.
And I now see that he has another one that I hadn't heard anything about ... "Handsaws: Tune-up, Setup & More" - I'll be in that too!
Handsaws - ShopWoodworking.com

I know that there have been other ones before ... Tom Law in particular that I will be trying to get hold of and watch. Has anyone seen it and can they please report on it? ... although it occurs to me I should have a search in the forum because it's probably in there ... I'll do that too.

Nice link BTW:
Hand Saw Sharpening by Tom Law

(Hand Saw Sharpening at Tools For Working Wood)

Having search online a little, 2 more links ... one from 2010 with sad news ...

The Village Carpenter: Tom Law: HandSaw Sharpening Guru

Tom Law's Saws | Norse Woodsmith



And ... I've only skimmed this one atm, but it mentions building a vice for holding the saw.

Sharpening Hand Saws | Norse Woodsmith

My actual question, before I got carried away with the online links , was this ...
When starting a handsaw cut, you often need to establish a start to the cut by pulling the saw backwards next to your thumb, and then attempting to cut forwards ... which it is not always ready for ... so repeat, etc

Ron Herman in the DVD does this, using the front (toe) of the saw ... and I've done that ... and I have two saws here that have a higher pitch at the front of the tooth-line than along the rest ... so OK fine. I get that.

But even in the DVD, demonstrating/testing a freshly cut saw, in the starting a cut he draws back with the saw, pushes forward and gets a tiny bit of bowing/bending of the saw as it doesn't get going, then draws back once more and he's off and running.

It seems to me that it would make more sense to use the section under the handle (heel) to start a cut because of the stiff connection to your hand grip ... ie there is not a couple foot of spring steel in between your cutting point and your hand. I am picturing pulling back a little, then pushing forward, back, and forward using the heel before then taking longer and longer strokes to involve the rest of the teeth of the saw.

*If* this makes sense to anyone else, then the question is ... what shape to apply to the last how many inches of saw teeth to help this process. I haven't experimented with this very much yet, it's just a question I have been wanting to ask. Chippy? IanW? anyone?

Cheers,
Paul.

Originally Posted by pmcgee

My actual question, before I got carried away with the online links , was this ...
When starting a handsaw cut, you often need to establish a start to the cut by pulling the saw backwards next to your thumb, and then attempting to cut forwards ... which it is not always ready for ... so repeat, etc

Ron Herman in the DVD does this, using the front (toe) of the saw ... and I've done that ... and I have two saws here that have a higher pitch at the front of the tooth-line than along the rest ... so OK fine. I get that.

But even in the DVD, demonstrating/testing a freshly cut saw, in the starting a cut he draws back with the saw, pushes forward and gets a tiny bit of bowing/bending of the saw as it doesn't get going, then draws back once more and he's off and running.

It seems to me that it would make more sense to use the section under the handle (heel) to start a cut because of the stiff connection to your hand grip ... ie there is not a couple foot of spring steel in between your cutting point and your hand. I am picturing pulling back a little, then pushing forward, back, and forward using the heel before then taking longer and longer strokes to involve the rest of the teeth of the saw.

*If* this makes sense to anyone else, then the question is ... what shape to apply to the last how many inches of saw teeth to help this process. I haven't experimented with this very much yet, it's just a question I have been wanting to ask. Chippy? IanW? anyone?

Cheers,
Paul.

i'll try and make this quick i'm off to the football shortly.

crikey! some question there that seem reasonable but for the life of me i couldn't be sure how i do it, my mind couldn't remember, so i just went out picked up a couple of saws (old 6-7 point hand saw and a carcase BS) to see where the muscle memory took me

before i get to that though, i havnt seen the videos but immediately i can say if you are bowing the saw at the beginning then you havnt got good control and are probably starting in the wrong place (wrong angle) or your set up and or stance is off a tad

anyway, you can start where ever you like, no set rule contray to what people might say imo, but having said that there is a right place at least a place that produces the the neatest cut and the easiest with most control but its not always toward the toe or toward the heal, it depends on the height of the timber you are wanting to cut, if it is positioned lower (say on a low saw stool) then to start the saw will be more toward the toe if the stock is higher, say in a bench vice or on a bench hook or bit higher saw stool, then the start can be more toward the heel (more so with a panel or hand saw, a rip saw tends to be better starting from the toe) which gives the most comfortable start and most control (just forward of the handle with a hand saw not under it). with a back saw i tend to start using the teeth more toward the front, whether CC or rip (not the first couple of inch though, just back a bit more than that) but again it varies a tad depending on height of the timber your cutting..its ok to start closer to heal (it works, but not ideal) of the BS but its better to use toward the front, you get to see the line your cutting to easier, and easier to cut square, also because the BS are shorter it works out a similar position (distance from hand to place saw touches timber) to where you place a hand saw when you place it down to meet the timber...

and thats pretty much the key to it, the angle of starting is what gets the cut started with the most ease and control and the neatest cut..i find that no matter what saw i pick up, what height the work is at, i automatically place the saw down to work at angle that is needed to make a neat easy start, i dont think about whether i am using the the saw toward the toe or heal..if i force myself to use the toe (say CC hand saw) when i naturally should be using the heal (or vice versa with a rip) then it mucks up my stance or wrist, shoulder etc line up which is worse than any other rule someone might tell you...


i think ppl should practice a bit with a BS to make sure they really need some finer teeth added, not just a bit, a least a hundred or more times (over a number of days), i think with a 15-16 ppi saw you might be satisfied they are easy enough to start..heck i get very neat and easy cuts with a 7ppi saw..i'm not saying that its bad to have a few 18-20ppi on a 15ppi saw, just that 15-16ppi is very fine and if one is having trouble getting started then technicque might need a bit of practice--on a 10-12ppi saw then 15ppi might be a bit more useful, the less ppi there is then the more useful it gets

anyway
i'm off to the footy

Originally Posted by pmcgee

My actual question, before I got carried away with the online links , was this ...
When starting a handsaw cut, you often need to establish a start to the cut by pulling the saw backwards next to your thumb, and then attempting to cut forwards ... which it is not always ready for ... so repeat, etc

Ron Herman in the DVD does this, using the front (toe) of the saw ... and I've done that ... and I have two saws here that have a higher pitch at the front of the tooth-line than along the rest ... so OK fine. I get that.

But even in the DVD, demonstrating/testing a freshly cut saw, in the starting a cut he draws back with the saw, pushes forward and gets a tiny bit of bowing/bending of the saw as it doesn't get going, then draws back once more and he's off and running.

It seems to me that it would make more sense to use the section under the handle (heel) to start a cut because of the stiff connection to your hand grip ... ie there is not a couple foot of spring steel in between your cutting point and your hand. I am picturing pulling back a little, then pushing forward, back, and forward using the heel before then taking longer and longer strokes to involve the rest of the teeth of the saw.

*If* this makes sense to anyone else, then the question is ... what shape to apply to the last how many inches of saw teeth to help this process. I haven't experimented with this very much yet, it's just a question I have been wanting to ask. Chippy? IanW? anyone?

Cheers,
Paul.

the Maggies won this morning...

just on that first bit of pulling the saw back to start, i have often heard (and seen) that advice now and again over the years, often they are referring to making a line/incision with the back of the teeth in which the saw can ride in on its forward cut...its generally not a good practice imo to force the teeth down to make a starting line (some timber is too hard anyway), feels horrible and i reckon it must damage the teeth a bit (not so much with a CC saw that has filed back bevel of the teeth). with a sharp saw i suggest pulling the saw back with tips of teeth just feather (barely, almost not at all) touching the timber along side your line, with just the very tips of the teeth, then on the forward stroke barely a fraction lower, each subsequent stroke is just a fraction lower with more downward pressure to it..cant go wrong, you get a very neat entry to the timber, drawing the teeth back with pressure trying to make a starting kerf feels like being thrown down a concrete staircase sitting in a shopping trolly, you feel every bump, particularly if its a 4-1/2 rip saw, doesnt do the teeth much good either is my feeling.. though all rules can be broken so long as there is a reason for doing so


cheers
chippy

Paul - I've been out of action for a couple of days, so just reading this thread now. I really can't add anything much to what Ch!ppy's has already said. My experience is far more limited, but tends to match with what he says.

Mucking around with altering pitch & rake on the toe of back saws has certainly led me to much the same conclusions as his. It's more bother than it's worth, unless you are cutting a lot of hard woods, using a saw that's a lot coarser than optimal. I think easing the rake on the first 30mm or so is not a bad idea, it does help sometimes, and doesn't do any harm. As Chippy says, with an already-toothed saw, you are stuck with either doubling the number of tpi, or filing off several years' worth of good saw plate, if you want something different.

However, altering the rake is dead easy. I use a stick on the end of my file when cutting new teeth or re-forming after a very heavy jointing, which helps me keep a constant rake angle. All you need do is tilt the stick back to increase the rake by the desired amount on tooth 1, then gradually bring it back to level as you form the first 30-35mm of teeth. There are no rules of thumb that I found to give me a guide, so I just went with instinct and started around 20-25 degrees for the first tooth, then back a degree or so for tooth 2 & so on until I hit the 'normal' rake.

The whole question of rake angles is something I'm still working on! The suggested angles I've come across tend to be from northern hemishphere publications, where they cut a lot of softwoods and hardwoods that are relatively soft compared with some of the cast-iron that poses as wood down here. So rake angles you'll see in print tend to be a bit aggressive, on average, under our conditions (IMO).

There is another major influence, too, & that is the skill of the sawyer. It seems strange to me that there is so much fuss made about starting cuts. As Chippy says, once you've done it a few hundred times, it becomes second nature (though still occasionaally catches me out in some woods!) to just ease the saw over the edge, with enough presure to keep it aginst the line, but not enough to make it bite hard - just a gentle 'rasping' to deepen the kerf enough that more than one tooth is riding. Then over a stroke or three, you let the weight of the saw bear on the wood as you move into your normal sawing rythmn & full strokes. It's harder to describe than do... If I saw a blade bowing as I started, even a fraction, I would be seriously worried about my technique, or the saw (or both)!

The rake angles I like to use for general-purpose small saws are bout 12-15 degrees for crosscuts and 8-10 for rips. These are baased on my own fiddling about, the aws I own & the types of wood I cut, so may well not suit everyone. Those angles are still pretty aggressive on many of the woods I cut, and some might find them too much so. I've watched a lot of folks use saws, and it does seem to take a while to learn to ease up and let the saw do the work, whilst still maintaining full control of where it's going. I can still hear my old dad admonishing me for hanging onto a saw like it was going to bite me (which it sometimes did!) and forcing it into the wood.

Matching the number of teeth to the width of the kerf is really important for effficient sawing. Somewhere between 6 & 10 teeth in a cut is ideal, but of course you can't always achieve that, and no-one would be bothered counting, you just get used to reaching for an appropriately sized & toothed saw for the job, which means having more than one or two saws available....

When starting out on saw sharpening, I think the two most important parameters to get right are eveness of tooth height, & correct set. You want set on a saw for two reasons. One is to prevent binding, and the amount for this varies with the wood you are cutting and the direction - rip needs less than crosscut, and softwoods generally need a little more set than dry hardwoods. The other important function of set is that it gives you a little 'steerrage way'. These two functions need to be achieved without excess, which leads to more wood being removed than necessary, and vibration. If a saw rattles in the cut, it's most definitely over-set.

Getting the set dead even is an acquired skill that I'm still working on. While you can ease a wandering saw by stoning off the teeth a bit on the side it cuts toward, I would much rather have it run straight without that step! Most times I get it right, but occasionally I have a freshly sharpened saw that wants to be a jigsaw.....

While most of us simply don't sharpen enough saws to become experts, it's still worthwhile persevering until you can do a decent job of it. It doesn't take all that long to get good enough that you have saws that cut quickly & straight. A really good saw is one of life's great pleasures, I reckon.

Cheers,