Thread: Chainsaw ripping blade... but not a rip cut?

Correct

When ripping with a chainsaw the cutters have to crosscut every fibre each pass. No way the saw can pull out nice big chips like in normal cutting. Hence sharpening the cutters at different angles and often using skip tooth chains to concentrate the cutting force on a lesser umber of cutters.

Cheers

Ian

Correct me if I'm wrong but if you are cutting down the length of the log you are ripping the timber not cross cutting it.

When you cross cut you are cutting across the grain. When you are ripping you are cutting with the grain. The fact that the saw is moving across the log when you are milling it lengthwise does not mean you are crosscutting.

Have another think about ripping a log with a chainsaw Bazza.

The bar is at 90 degrees to the log so its cutting across the ends of the fibres and not ripping along the grain the same way a circular saw does where the teeth run mainly along the fibres.

But that said the chainsaw ripping blades have been developed from field experience to get good performance.

You are all correct.
Ripping a log with a chainsaw is not ripping as we traditionally look at it, but we are ripping along the grain which I guess is technically ripping, not ripping as in going parallel with the grain as in "ripping" just ripping as in going with the flow, ripping with a chainsaw is a pain, much better if we could rip like as in a handsaw, much quicker easier and gooder.

There has been a lot of discussion about this on various sawmilling groups on the web which I have followed with some interest. It was not until I drew a diagram for myself and ran a chainsaw in the 3 orientations that I could really appreciate it. It's not the blade but the teeth that you have to consider.

True ripping ( blade alignment C in the picture) has most of the cutting surface of the moving parallel to the grain. Planing with the grain is probably the best example. If the teeth are sharp this cut makes long shards or wisps of wood.

Blade alignment A and B have most of their cutting surfaces perpendicular to the grain so are always mainly cross cutting. This cutting makes chunks of dust.

What is not appreicated is that circular ripping blades partially cut cross grain and partially rip cut. A shallow rip is still effectively a cross cut which is why cross cut blades can still shallow rip. Try doing this with deep or blind rips and suddenly you will run into trouble often because too much sawdust will build up between the teeth.

With hand saws it depends how you hold the saw but true rip only cutting is usually only possible with short pieces.

If you want to see true rip cutting with a chain saw, align you blade as show in C and look out for the huge volumes of long curly shards that are generated in this way, it's quite fun for those of us who like to generate interesting sawdust.

Originally Posted by outback

You are all correct.
Ripping a log with a chainsaw is not ripping as we traditionally look at it, but we are ripping along the grain which I guess is technically ripping, not ripping as in going parallel with the grain as in "ripping" just ripping as in going with the flow, ripping with a chainsaw is a pain, much better if we could rip like as in a handsaw, much quicker easier and gooder.

So if you are ripping with a hand saw along the length of a piece of timber which I have done 100's of times as a patternmaker and in the building trade I should have been using a crosscut saw instead of a rip saw which is very difficult believe you me.

When ripping with a hand saw you don't have the saw at 90 degrees to the timber, more like a 30 to 60 degree angle and only when finishing a blind cut would it be at 90 degrees to the timber so in practice it when ripping with a chain saw with a ripping chain it would be better to have the bar at an angle to the log and with a hand mill as has been posted by AndyMac it would be better to have the toe of bar in front of the heel so as to get more of a rip action.

I still believe it is ripping. Sorry but that is the way that I see it from my years of experience.

Thanks for that diagram bob. That's exactly what I was thinking
Plane A is indeed a crosscut. Plane C is indeed a rip cut for a chainsaw.

The reason I had the thought was because I got a "ripping" chain, and it was basically a skip-tooth chain still with 30 degree teeth and was wondering why it was still so bloody hard to "rip" a board... and thats because it wasn't rip-cutting at all

Maybe I'll just file the teeth down to 5 degrees as many chainsaw milling folk seem to recommend

There was an article in FWW many years ago about chainsaw milling by Will Mallof. He used totally different tooth geometry (mainly large hook angles) from current milling practises but it worked well and he is well regarded by chainsaw millers.
I got the info from the Book - FWW On Making & Modifying Machines.

So regardless of whether it is cross cut, rip or endcutting, ripping chains improve the effectiveness of chainsaw milling

Bazza,

I detect a note of someone looking for a fight.

Ya won't get one from me, I agree with what you say 100%.
When you rip with a handsaw, your 30-60 degree angle aligns the saw closer to Bobs diagram, with a mill you are forced to attack it at 90 degrees. Why do you hold your saw at 30 instead of 90 degrees? Cos' its gooder to do so, right?

When using a mill on a smal log I "skew" it to get as much angle I can from the bar length.

I reckon Bob's got it right when he compares planing along the grain as opposed to planing end grain.

Originally Posted by Barry_White

So if you are ripping with a hand saw along the length of a piece of timber which I have done 100's of times as a patternmaker and in the building trade I should have been using a crosscut saw instead of a rip saw which is very difficult believe you me.

Nope - your choice of what is called a rip saw is correct!. The standard ripping hand saw tooth profile takes all this into account and acts like a chisel to chip the fractions of mils of the tops of fibres as well as like a plane to slice/peel long bits of fibres. It's called a rip saw but it has this cross grain chipping/cutting action capability. If we were to perform full 100% ripping along the grain then a (slightly) different tooth shape and maybe TPI would work better.

Originally Posted by Barry_White

When ripping with a hand saw you don't have the saw at 90 degrees to the timber, more like a 30 to 60 degree angle and only when finishing a blind cut would it be at 90 degrees to the timber so in practice it when ripping with a chain saw with a ripping chain it would be better to have the bar at an angle to the log and with a hand mill as has been posted by AndyMac it would be better to have the toe of bar in front of the heel so as to get more of a rip action.

Yep, Many of the chain saw forum postee's recommend a slight angle to the perpendicular (usually toe back) but a better performance will be gained by using a skip chain, which many call a "ripping chain", even though its "technically not ripping.

Originally Posted by Barry_White

I still believe it is ripping. Sorry but that is the way that I see it from my years of experience.

That's Ok - it doesn't matter what we call it - I say tomayto and you say tomahto - we know what we mean.

Cheers

You guys have lost me completely...the way I see it cross cutting is across the grain (as in B in Bob's diagram) and anything along the grain is ripping!! Doesn't matter surely which way you angle the saw blade? Are there degrees of how much along the grain you judge it to be, or which part of the timber you're in? Sounds a bit like semantics to me!

Cheers,

OK I submit.

Originally Posted by Andy Mac

You guys have lost me completely...the way I see it cross cutting is across the grain (as in B in Bob's diagram) and anything along the grain is ripping!! Doesn't matter surely which way you angle the saw blade? Are there degrees of how much along the grain you judge it to be, or which part of the timber you're in? Sounds a bit like semantics to me!

Cheers,

Blame Dean he started the controversy.

Baz, don't submit, I agree with all you say, we will stand and fight the bloighters shoulder to shoulder.


Andy, I agree with you, all sorta semantics, sorta. BUT it is easier to plane along the grain than end end grain.