SAW-TOOTH SETTING ADVICE

[Racers]

Hi, Chaps

Here they are...

The anvils

Measurements, maximum depth of spiral and width of spiral

Angle

The one on the right is what I think is the older one, but the anvil looks cheap and the bevel is rounded over, the left hand one is nice and crisp compared to it. But the casting is more ornate on the right hand one, the other seems like its been reduced of any unnecessary ornamentation.

Pete

 

[Corneel]

This is a very interesting thread, so I thought after long time lurking, let's registrate.

Bugbear, your diagrams of the Eclipse 77 are very enlightning. Now I understand why they made the tpi gradiations on the anvil. So your tooth will be bend at the right height . A 6tpi tooth is a lot larger, so will need to be bend a lot lower then a 12tpi tooth.

The problem though is the rediculous amount of set you get at the 6tpi setting. My sawset would geive me something like 1mm on both sides! Even for a 6tpi saw in wet firwood, that is way too much. In fact the neccessary amount of set doesn't variate much between low or high tpi's.

So the perfect Eclipse 77 anvil would have one setting for set and the edge of the anvil would have gradiated angles. A 6tpi, being a much larger tooth, you would need a much lower angle then at 12tpi, to be able to bend the tooth at a lower point. Of course you would then need several anvils for differnent amounts of set.

But this being not a perfect world, I just use the Eclips77 mostly in the 12 tpi setting, even when I set a 6tp saw. And I have another one with a narrower hammer and even less set, because I grinded down the anvil, for when the time comes to sharpen my finest backsaws.

 

[xy mosian]

Hi, Corneel welcome to the 'Mad house'

I was just beginning to think this thread must be getting a bit dry for onlookers and here you are. I agree about the calibration of the anvil on the '77, I just ignore it. However I do find the tool to be relatively easy to use and it does give repeatable results along the blade.
That's a nice approach to making a setting tool for finer toothed saws. One that has been mentioned here abouts. I must get around to grinding the thickness of my second anvil down. I think I'll have another look at bugbear's changes to the chamfer angle too.

Of course for finer teeth I'll need to add more magnification too

xy

 

[xy mosian]

Pete, if it is of interest the '77 on the right of your picture looks just like the one I bought thirty years ago. The anvil looks the same too although I haven't done those measurements.

Just in case any want to see other types of saw setting plier:-

http://members.acmenet.net/~con12a/saw% ... rindex.htm

Shame there isn't more information really

Have fun

xy

 

[Corneel]

Just been thinking it over a bit more.

Adjustable sawsets don't really work. You can't change the angle of the hammer, if you would use different angles for different tooth sizes. And when you use the same angle and same set, the bending point is probably too high on the coarse teeth and too low on the finer ones.

So in fact you need a seperately prepared sawset for every possible tooth.
That's probably a bit too much. But you could lump them into 3 or 4 groups and prepare a sawset for each group, and never change the setting of these anymore. So get out the sinus and tangus tables and start designing the perfect sawset geometry :lol:

 

[bugbear]

So - does anyone know of a sawset design where the AMOUNT of set and the POSITION of the bend can be adjusted separately?

Since such a design is neither common nor dominant, I'm guessing there are definite problems with making it.

BugBear

 

[xy mosian]

Ah Corneel, I foresee some grand discussions about correct angles and bend points coming up. Have you formulated any thoughts yet?

xy

 

[AndyT]

So - does anyone know of a sawset design where the AMOUNT of set and the POSITION of the bend can be adjusted separately?

Since such a design is neither common nor dominant, I'm guessing there are definite problems with making it.

BugBear

Here's one:

It's by CK, made in Germany. Not uncommon on ebay - I bought this one from Bristol Design for £4.50.

There are two adjustments. One stop limits how far down on the tooth the bend comes. Here it is for a small tooth:

and here it is set for a large tooth:

The other stop (the setscrew at the bottom of the picture) controls how far away from vertical the bend goes. (I've not changed it between these two photos, and I'm holding the set in the 'bend' position.)

 

[Corneel]

tpi width height bendheight Aset=0.2 Aset=0.25 Aset=0.3
4,5 5,64 3,26 1,95 2,93 3,66 4,39
5,0 5,08 2,93 1,76 3,25 4,07 4,87
5,5 4,62 2,66 1,60 3,58 4,47 5,36
6,0 4,23 2,44 1,47 3,90 4,87 5,84
7,0 3,63 2,09 1,26 4,55 5,68 6,81
8,0 3,18 1,83 1,10 5,20 6,49 7,77
9,0 2,82 1,63 0,98 5,84 7,29 8,73
10,0 2,54 1,47 0,88 6,49 8,09 9,68
11,0 2,31 1,33 0,80 7,13 8,89 10,63
12,0 2,12 1,22 0,73 7,77 9,68 11,57
13,0 1,95 1,13 0,68 8,41 10,47 12,50
14,0 1,81 1,05 0,63 9,05 11,26 13,43
15,0 1,69 0,98 0,59 9,68 12,04 14,35
16,0 1,59 0,92 0,55 10,31 12,81 15,27


Okay, so I made a table of all dimensions of several tooth sizes.
Sorry the layout of the table got lost between excel and this forum, so it is a bit hard to read

tpi => the tpi of the saw
Width => width of tooth in mm
Height => height of tooth in mm with rake = 0 and sharp gullets.
Bendheight => 0.6 * height, a good spot to start the bend
Aset=0.2mm => arctan((0.2/2)/bend height) this is the angle in degrees over which the tooth must be bent, with a 0.2mm set.
The same for set=0.25 and set=0.3. With set I mean the kerfwidth-sawplate tickness.

Some caveats
Gullets aren't sharp, they are rounded. So the tooth doesn't really start so deep. So maybe 0.6 of the height for the bending point is too deep.

I think you need to set the teeth somewhat further because steel always springs back a little.

you can't use these measurements directly on the anvil, because the top of the toothline doesn't reach all the way to the top of the anvil. So you should add that little bit to the heights.

As you can see it is all very small. I doubt you're able to accurately translate these numbers to the anvil with just handtools. Nonetheless, I just bought another Eclipse77, so I have something to play with.


BTW, that CK sawset looks very interesting. Is it also suitable for small teeth?

 

[AndyT]

BTW, that CK sawset looks very interesting. Is it also suitable for small teeth?

Not as much as you might hope. The limiting factor is the thickness of the hammer (ie the bit with the graduations on). It's about 3.5mm thick, tapering to 1.5mm on the end, so with very small teeth it touches not only the one you want to bend, but the two neighbouring teeth as well.

But the design is a good example of making the two adjustments (amount of bend, and distance from tip for the bend to start) separately. It could perhaps be filed down to make a version just for fine saws.

Has anyone tried?

 

[bugbear]

BTW, that CK sawset looks very interesting. Is it also suitable for small teeth?

Not as much as you might hope. The limiting factor is the thickness of the hammer (ie the bit with the graduations on). It's about 3.5mm thick, tapering to 1.5mm on the end, so with very small teeth it touches not only the one you want to bend, but the two neighbouring teeth as well.

But the design is a good example of making the two adjustments (amount of bend, and distance from tip for the bend to start) separately. It could perhaps be filed down to make a version just for fine saws.

Has anyone tried?

If I'm reading the picture right, the saw isn't clamped during the setting operation, it just "sits" in the slot, which is formed in one of the jaws.

The "tooth bender" is part of the other jaw.

There is no counter part of the #77's "anvil".

Is that right?

BugBear

 

[AndyT]

Yes, BB, you are reading it right.

There is one more helpful subtlety not visible in my photos - the adjustable stop for the depth of the bend has a little notch filed in it. The tip of the tooth sits in the notch, making it fairly easy to locate and use. But the fixed open mouth is a bit of a problem.


I just spent a few minutes looking at the site Xy linked to, and a German site linked to from there. Good grief, there are hundreds of variants!

Over the last couple of centuries, others have looked at this problem just as we are looking at it, and lots of them had a little idea of how to make an improvement.

Some of the designs look really clever, and plenty of them have both size and positioning adjustments. Nothing new under the sun...

 

[pedder]

16,0 1,59 0,92 0,55 10,31 12,81 15,27

BTW, that CK sawset looks very interesting. Is it also suitable for small teeth?

Hi Kees,

15,27mm :?: :lol:

Hand sets are hand powered. You will never work precise within the 1/100mm with a hand set. And there is no need for! It is an advantage that the hand is a bit irregular. Think of hand stitched rasps.

I have only one set of that Kind, a present of a friend.

The gap or slit is too wide for thin blades. And the "tooth bender is to thik to bend smal teeth. IMO it is to coarse in every part but the system would work on finder tooth, too.

 

[Corneel]

16,0 1,59 0,92 0,55 10,31 12,81 15,27

BTW, that CK sawset looks very interesting. Is it also suitable for small teeth?

Hi Kees,

15,27mm :?: :lol:

Degrees, degrees!

Well, Excell can easilly pour out 10 decimals. the idea was if I could find some reasonable numbers so I can make 3 sawsets to set 3 groups of saw. I must ponder this a bit more. Tomorrow I'll pick up another Eclipse for just 4 euro, so i have something to experiment with.

 

[bugbear]

There is one more helpful subtlety not visible in my photos - the adjustable stop for the depth of the bend has a little notch filed in it. The tip of the tooth sits in the notch, making it fairly easy to locate and use.

That's a nice touch.

BugBear

 

[pedder]

What sort of set would you use on, say, a 20 tpi saw? I hope you don't mind me asking.

Hi xy mosian

I don't believe that the amount of setting depends on tpi.

I believe it depends on cutting depth, experience of the sawing person, moisture of the wood, kind of wood, length of the saw, length of the cerve....

I don't set a 15tpi dovetail saw more than a 20tpi dovetail saw. How much? That it cuts well and fast.

Okay, I'll tell when i measured after the weekend.

Cheers
Pedder

Hi I measured. 0.11-0.13mm set is what I get minimal from my eclipse and I like that. I think less set would mean no set. But that is only my opinion.

Cheers
Pedder

 

[pedder]

]Hi pedder

I have been buying up a few 77's off ebay for this very purpose, but haven't go t clue how small to go with the filing, or exactly where to file. Also, I have read that to get the best from it you really need to file the anvil too.

Is there any chance you could post a few close up pics of yours so I know where to start?

Sorry for hijacking the post.

Cheers

Mark

Hi Mark, I'm about 250km away from the set but I'll try to make pictures on the weekend.

Cheers Pedder

Hi Mark,

my camera would not show the details.

But I think th thread made clear, where to start.

Cheers Pedder

 

[xy mosian]

What sort of set would you use on, say, a 20 tpi saw? I hope you don't mind me asking.

Hi xy mosian

I don't believe that the amount of setting depends on tpi.

I believe it depends on cutting depth, experience of the sawing person, moisture of the wood, kind of wood, length of the saw, length of the cerve....

I don't set a 15tpi dovetail saw more than a 20tpi dovetail saw. How much? That it cuts well and fast.

Okay, I'll tell when i measured after the weekend.

Cheers
Pedder

Hi I measured. 0.11-0.13mm set is what I get minimal from my eclipse and I like that. I think less set would mean no set. But that is only my opinion.

Cheers
Pedder

Thanks Pedder. A good ball park figure, much appreciated.
xy

 

[Corneel]

The sawset I bought today is a good one, but one of the older ones I have is totally worn out. So I still "only" have two sawsets.

I have been thinking a bit about changing one of these, but I think it's not worth my time. The standard angle is pretty good for all the medium to fine tooth saws. Only the coarse saws like 5-7 tpi are set rather high on the tooth. But I don't know if that is a problem. At least the saws I sharpened and set with the eclipse 77 cut like a dream.

So I think I'll just convert one of the sawsets for very fine work. Narrowing the hammer and maybe grinding of some of the anvil if it gives too much set. Just a warning, make sure you don't remove too much when narrowing the hammer, just the very tip. Otherwise it isn't guided securely anymore and can move while tensioning.

 

[pedder]

Hi Paul,

I inspected my two eclipse 77 and both had a hammer/anvil configuration like the right one. But only at the high numbers. At the low number the hammer matched the anvil.

That is probably the reason Why I didn't have to grind the hamers face.

Cheers
Pedder