Saw setting issue

[tibi]

Hello,

I have purchased some vintage saws and now I am going to sharpen them and set them.

The saw before setting binds at the heel, but not at the toe. The plate thickness at the heel is 1,1 mm and at the toe is 0,9 mm.

If the equal set is applied to the whole length of the saw plate, the kerf gets progressively thicker as the base plate is thicker. I think that that might be causing the binding. I think that the kerf + set should be equal or less at the heel, than at the toe for western saws.

Should I apply less set at the heel so that the base plate + set will remain consistent? I tried applying the maximum set (no.4 on my pliers), but it was still not enough at the heel part - I did the whole saw with the same setting.

I am ripping a well-dried beech as a test piece.

Thank you.

 

[pedder]

sounds like it is a well beloved and often sharpened saw, wich blade was taper grind.

the only way to solve in my understanding is to have the same width between the left and right teeth over the whole length of the saw. And yes you have to increase the amoubnt of set where the blade is thinner in sicrease where it is thicker.

Hope that is understandable.

Take Care
Pedder

 

[IWW]

While it might seem logical if you think about it, in practice you don't need to vary the set of a taper-ground saw. I have never heard of anyone doing it & I have always used the same amount of set toe-ro-heel on my saws without encountering any problems. If you are using a typical pliers-type set, it self-compensates because the anvil sets the outer limit of plunger travel so the tips of all teeth should be the same regardless of plate thickness. If you want to get very picky, you can point out that there will be slightly more 'spring-back' from the thicker teeth so in fact you will be applying ever-so-slighly less set at the thicker end, but that's becoming a little ridiculous...

My first thought would be that your saw is simply under-set. There's a fine line between enough & not enough and what's enough for an experienced sawyer may not be enough for someone new to hand sawing - forcing the saw instead of letting it cut "at its own pace" can cause it to bind In addition, newbies tend to constantly correct the cut making a wobbly kerf which may cause binding. Uneven set causing the saw to make a curved cut will also lead to binding. You usually need more set for sawing softwoods or any wood with a higher moisture content. And all of the negative effects are exacerbated by dull teeth.

If you want to get scientific about it, grab a set of feeler gauges and an accurate set of calipers. Measure the thickness of the plate just above the teeth (not along the top) and determine the mean thickness. Then use the feeler gauge to measure average width of several freshly-cut kerfs in dry wood. The 'ideal' is a kerf between 15 & 20% wider than the average thickness of your saw plate. If your kerf isn't at least 15% wider, your saw is definitely under-set.

And my recommended procedure for saw refurbishment is to reform the teeth (if necessary) first, set, then sharpen. Sharpening should only require a single stroke (use a new file or new edge for the sharpening run) to refine the edge & remove the slight deformation caused by setting..

Cheers,
Ian

 

[xy mosian]

Isn't any given tooth set away from the setting tool anvil?
To me that would suggest that the width of the kerf is dependant on the height of the tooth rather than blade thickness.

Of course I could well be wrong.

geoff

 

[tibi]

While it might seem logical if you think about it, in practice you don't need to vary the set of a taper-ground saw. I have never heard of anyone doing it & I have always used the same amount of set toe-ro-heel on my saws without encountering any problems. If you are using a typical pliers-type set, it self-compensates because the anvil sets the outer limit of plunger travel so the tips of all teeth should be the same regardless of plate thickness. If you want to get very picky, you can point out that there will be slightly more 'spring-back' from the thicker teeth so in fact you will be applying ever-so-slighly less set at the thicker end, but that's becoming a little ridiculous...

My first thought would be that your saw is simply under-set. There's a fine line between enough & not enough and what's enough for an experienced sawyer may not be enough for someone new to hand sawing - forcing the saw instead of letting it cut "at its own pace" can cause it to bind In addition, newbies tend to constantly correct the cut making a wobbly kerf which may cause binding. Uneven set causing the saw to make a curved cut will also lead to binding. You usually need more set for sawing softwoods or any wood with a higher moisture content. And all of the negative effects are exacerbated by dull teeth.

If you want to get scientific about it, grab a set of feeler gauges and an accurate set of calipers. Measure the thickness of the plate just above the teeth (not along the top) and determine the mean thickness. Then use the feeler gauge to measure average width of several freshly-cut kerfs in dry wood. The 'ideal' is a kerf between 15 & 20% wider than the average thickness of your saw plate. If your kerf isn't at least 15% wider, your saw is definitely under-set.

And my recommended procedure for saw refurbishment is to reform the teeth (if necessary) first, set, then sharpen. Sharpening should only require a single stroke (use a new file or new edge for the sharpening run) to refine the edge & remove the slight deformation caused by setting..

Cheers,
Ian

Thank you Ian for your insight. You were right. The teeth are definitely underset. The issue was that I sharpened the saw and did not check if the teeth are in the same line. I just followed the original sharpening. Then I have found out that the tooth line is inconsistent, so I filed the teeth until I saw a flat spot on every tooth and reprofiled them again. Now the set is much better. The saw works well and cuts straight. Maybe I would add just a little more set, but my pliers are on the max. And I do not dare to set teeth with a screwdriver.

 

[IWW]

Isn't any given tooth set away from the setting tool anvil?
To me that would suggest that the width of the kerf is dependant on the height of the tooth rather than blade thickness.

Of course I could well be wrong.

geoff

Geoff, just to get our terminology on the same page, I refer to the lump of metal the tooth is pushed against as the 'anvil', the bit wot pushes it over as the 'plunger'.

The anvil on the common types of sets has a spiral chamfer of constant angle but increasing width. It is usually recommended that you set the top third of a tooth, i.e. the bend starts two thirds up the tooth from the bottom of the gullets, so you set the anvil accordingly. The taller the tooth (i.e. fewer tpi), the more gets pushed over, so technically, the width of set does depend on tooth height to an extent. One of the problems with this type of saw set is that the chamfer angle on the anvil is constant, it's the width that varies, so the only way to vary width of set is to push more or less of the tooth over - not theoretically deal, but it works in the real world.

Most saw-sets struggle with small teeth. The anvils are not particularly hard and later examples (post 1950s) or the cheaper 'knock-offs' were not made all that accurately in the first place. In addition, they all become worn with heavy use, especially around the finer initial part of the chamfer that you need for small teeth. Since you only need the tiniest chamfer to set teeth smaller than ~16tpi according to the rules, it may be hard to find a position of the anvil that will achieve this (the plunger is also often far too wide to fit a single tooth & needs modifying). As a consequence many saws with very small teeth that I've seen were grossly over-set, with the bend starting right at the point of the gullets, which is not the best because it distorts the teeth too much & puts additional stress at the points of the gullets which can promote tooth breakage.

Saw sharpening is as much art as science - there are several objective factors & an equal number of subjective factors involved. It takes a lot of practice to become really good at it, but most of us can manage to get a saw cutting decently after a few tries. As I read somewhere a long time ago, even a not-so-well-sharpened saw cuts better than a dull one....

Cheers,
Ian

 

[xy mosian]

Geoff, just to get our terminology on the same page, I refer to the lump of metal the tooth is pushed against as the 'anvil', the bit wot pushes it over as the 'plunger'.

The anvil on the common types of sets has a spiral chamfer of constant angle but increasing width. It is usually recommended that you set the top third of a tooth, i.e. the bend starts two thirds up the tooth from the bottom of the gullets, so you set the anvil accordingly. The taller the tooth (i.e. fewer tpi), the more gets pushed over, so technically, the width of set does depend on tooth height to an extent. One of the problems with this type of saw set is that the chamfer angle on the anvil is constant, it's the width that varies, so the only way to vary width of set is to push more or less of the tooth over - not theoretically deal, but it works in the real world.

Most saw-sets struggle with small teeth. The anvils are not particularly hard and later examples (post 1950s) or the cheaper 'knock-offs' were not made all that accurately in the first place. In addition, they all become worn with heavy use, especially around the finer initial part of the chamfer that you need for small teeth. Since you only need the tiniest chamfer to set teeth smaller than ~16tpi according to the rules, it may be hard to find a position of the anvil that will achieve this (the plunger is also often far too wide to fit a single tooth & needs modifying). As a consequence many saws with very small teeth that I've seen were grossly over-set, with the bend starting right at the point of the gullets, which is not the best because it distorts the teeth too much & puts additional stress at the points of the gullets which can promote tooth breakage.

Saw sharpening is as much art as science - there are several objective factors & an equal number of subjective factors involved. It takes a lot of practice to become really good at it, but most of us can manage to get a saw cutting decently after a few tries. As I read somewhere a long time ago, even a not-so-well-sharpened saw cuts better than a dull one....

Cheers,
Ian

Thank you Ian, I clearly was not fully considering the problem.
I do recall, some time ago, a thread dicussing Marples saw setting tool modifications. If I recall correctly the anvil, as above, could be modified by simply turning it over. This presents a face with no chamfer, just right for modification. Of course the spiral chamfer is difficult to achieve, but localised chamfers should be possible.
Thanks again for clarification.

geoff