Question about rip and cross cut saw teeth geometry

[Andrea]

When (at which fleam angle) a saw stops being considered rip-cut and becomes cross-cut?

I try to explain me better.
A saw is usually considered rip-cut when has 0 degrees fleam.
But, in practice, a saw with 1 degree of fleam works like a rip at 0 degrees.
And also with 2 or 3 degrees.

So, at how many fleam degrees a saw stops being considered rip-cut and becomes cross-cut?

I know that this is a question more philosophical than practical, but I'm interested in your point of view.

Cheers from Italy,

 

[Rob Platt]

A ripsaw will generally have slightly less teeth per inch but not necessarily so. The cut will be straight across i.e. 90 and the teeth will be straight i.e. vertical. The cross cut will be sharpened at about 45-60 degrees and will go slightly backwards as well so just off the vertical. Hope that makes sense.
All the best
Rob

 

[Alf]

I think Andrea's wondering more if there's a sort of "tripping point" where the fleam angle makes a marked difference in x-cutting vs. rip. Yes? Something like that?

Must confess my only philosophical thought in connection with saw teeth is philosophically resigning myself to sharpening them...

 

[Modernist]

So I suppose 9 tpi with 5 deg fleam would be a cripcut. Perhaps this is the missing particle they are searching for at Cern

 

[Rob Platt]

If we use a cross cut to go along the grain does that make it a rip saw? If a dog is born in a stable does that make it a horse?

Very soon we`ll be discussing the pain timber feels as the chain saw chops through its base in the prime of its life and if you listen carefully as its coming down you can hear it SCREAM.

All teh best
Rob

 

[Rob Platt]

So I suppose 9 tpi with 5 deg fleam would be a cripcut. Perhaps this is the missing particle they are searching for at Cern

You must remember that there is also the fact that crosscut teeth are also angled backward as a well. There is a difference in the cutting action because of this slight backward angle. The chisel cut of the ripsaw with its 90 and vertical tooth is a lot different to the profile of crosscut tooth which tends to score the cut first. It`s not just the fleam angle.

Changing the angles on specific saw types can make for a specialist saw or just a badly sharpened hybrid

All the best
Rob

 

[Andrea]

I think Andrea's wondering more if there's a sort of "tripping point" where the fleam angle makes a marked difference in x-cutting vs. rip. Yes? Something like that?

Yes.
I'm afraid I did not explain me well.

Please, do not consider rake, slope, pitch, gullet radius, amount of set, sawplate thickness, handle angle, and Higgs boson, but only the fleam angle.

All the literature says that a rip-cut saw have zero degrees (or 90°, it depend by the point of view) of fleam angle.
But if I file the teeth alternately with 1 degree of fleam, I get a saw that, in practice, works as one with 0 degrees.
The same happen if I file it with 2 degrees an I think that the same happen with 3 degrees.
Which is, in your opinion, the "breaking point" where a saw ceases to perform as rip-cut and becomes efficient as cross-cut?

At 15 degrees?

I ask this because I'm testing some non-conventional saw theeth geometry with this in mind:
since a skew plane work with less effort maybe also a rip-cut saw with slightly skewed theeth work with less effort.
But I do not want to exaggerate because otherwise it becomes too slow, as a cross-cut one.

 

[pedder]

Hi Andreas,

to make is even more complicated:

In old Germany the fleam said nothing about rip or cross, because both pattern were filed at 90°. A cc has more rake, but that was the whole difference.

Please, do not consider rake, slope, pitch, gullet radius, amount of set, sawplate thickness, handle angle, and Higgs boson, but only the fleam angle.

If you file a saw with 0° Fleam, 25° Rake and 15° slope you have clearly a crosscut saw.

So my answer is the difference in rip and crosscut is not only fleam.



My easier answer is 5°.

Ciao
Pedder