what really takes out the chips?

[Kneejerk Bombas]

I have asked the guys from FISTA (Forest Industries Training Alliance) on a few different occasions about kick back with skip sequence chains and have been told it is actually slightly less than full comp chain.

 

[earache]

This is an excellent subject, as myself and many others have wondered about cutting times with full comp and full skip. I run a walkerized 372 with a 22" bar and full skip chain. My dad and I ran time comparisons with same powerhead, same wood, same length bar and chain. We ran through popple and red oak. Timed with full comp and with full skip. Each time, each cut, both woods, the full comp outcut the full skip. I will post times tomorrow night, as my time sheet is at work. Sorry about that fellas. When it comes to sharpening, there is no comparison. Full skip takes less than half the time. If I may add one question, wouldn't the full skip have a shorter life than full comp, since there are so many less cutters, so it would need to be sharpened more often? I did notice that when cutting lengtwise(ripping), the full skip plugged the cover more quickly than full comp.

 

[Art Martin]

Mike Maas,

First of all we need to get the terminology correct. The “depth gauge” on the chainsaw tooth is not a “raker” although we all use it often so it has become a coined word of expression. The severed chip that enters the space between the teeth gets caught up in the forward motion of the chain and is expelled from the cut.
The depth gauge is there to regulate the optimum cutting angle. Since it is always lower than the cutting edge and is in front of the cutting edge, there is no way that it can be construed as a raker. The raking action of the chain, with a hooded tooth, is the top plate that removes the wood that is severed by the side plate.
Now the “scratcher tooth” chain that was used in the ‘50s had a side cutter on either side of the chain that severed the wood. The center position of the chain had the true “rakers” that were the same height as the side cutters, they followed the side cutters and chiseled out the severed wood and again the wood was carried out by the forward motion of the chain, much like the forward stroke of a hand saw cutting a board.

Art Martin

 

[Kneejerk Bombas]

Originally posted by Art Martin
The depth gauge is there to regulate the optimum cutting angle.

I thought it was to regulate cutting depth.

So you say the chip is severed by tthe side plate, removed by the top plate, and carried by the chain links and momentum, but somehow don't pile up on the following depth gauge?
If you are cutting a 24"peice of wood, then on each pass there is 24 inches of little wood chips between each cutter. That's a lot of little wood chips. You contend that the sides and top of the cerf don't supply enough friction to slow the forward movement of the chips enough to have them start piling up on the next depth gauge?

I do appreciate correcting me on the terminology. What do you call the little tool that gauges how much you file the "depth gauge"? A depth gauge gauge?

 

[Art Martin]

Mike Maas,

You haven’t been paying attention. The depth gauge alone does measure the depth that the depth gauge on the chain tooth is lowered to, but it doesn’t regulate the optimum cutting angle. Only if you have an adjustable depth gauge, and understand what constitutes the optimum cutting angle, then you can determine what the setting should read at the different stages as the chain is filed back toward the back rivet. If you use a fixed depth gauge, forget it. I am surprised that your friends at the FISTA didn’t explain this to you. If they don’t understand it either, have them email me and I will explain it to them.
I covered this subject on the post: “ART MARTIN: Will the real logger please stand up.” It’s on page 11 of that thread.
Also before I forget, one gauge is enough, you can eliminate the second gauge, instead of saying depth gauge gauge.

Art Martin

 

[Kneejerk Bombas]

Originally posted by Art Martin


The depth gauge alone... doesn’t regulate the optimum cutting angle.

Art Martin

Originally posted by Art Martin


The depth gauge is there to regulate the optimum cutting angle.

Art Martin

The optimal cutting angle thing has me confused. I thought the only thing that happens as you file a tooth back is the tooth gets lower and thinner. So you get a thinner cerf cut, but the angles don't seem to change. What angles are changing and how does the depth gauge(the depth gauge that is part of a chain, not the depth gauge that is a filing tool) change them?

 

[Crofter]

I think some of this is a matter of semantics. I can see a problem with calling that THING ahead of the cutter a raker if that is not really its function. Then it could be referred to as a depth guage, or is the depth guage the jig that is used to file the THING that controls the tooths angle of cut. I see what Art is getting at that a different dimension is needed as the tooth wears down, to maintain the same angle of attack or cutting angle.

Frank

 

[WRW]

Call the one on the chain a depth guide, use the gauge to measure it.

 

[Crofter]

Most Efficient Chain Speed

Have read in one of the posts here that cutting efficiency drops off after a certain lineal chain speed. Is this true and if so is it because the chain elements start to surf on the chips and don't cut or is it because friction increases as the square of velocity (my doesn't that sound importament)

Frank

 

[Art Martin]

Crofter,

Finally, there is someone that understands the optimum cutting angle, I hope. When you stated in your post..."that a different demention is needed as the tooth wears down to maintain the same attack angle or cutting angle". Exactly.
You statement in the other post concerning..."cutting effiency drops off after a certain lineal speed". This is not true and is just more former Guru b.s. as was the other statement that pushing down by the operator doesn't make a faster cut. There need not be any surfing on chips if the operators are competent as Rotax Robert and Sawracer just to name a few, who know how much downward pressure to apply. Also the friction increase as the square of the velosity is not an important factor if your engine has enough power and the operator keeps the rpm's in the power band. This is why more efficiency is obtained by saws that are modified by Ken Dunn or Clearwater Dennis.

Art Martin

 

[Crofter]

The proof of the pudding is in the tasting

Art your work obviously gets results as does that of Ken, Dennis , Rotax etc. B.S. doesn't win many trophys. A lot of myths and old wives tales exist especially about something as subjective as saw performance. So many variables affect the outcome even with the best intentions, and once a person gets attached to his own pet theory he can get pretty persuasive about why it is so. I think some people believe that its the trees waving their branches causes the wind to blow! My sharpening has improved a heck of a lot and I am still experimenting with different things. It just makes it so much easier if you can understand WHY you do certain things and how the tradeoffs work. There certainly seems to be a lot of disagreement about skip VS comp chain. It would be cute if some of you chain saw scientists got an experiment together on this. You'd need someone honest though to keep it on the level. That might be the most difficult part of the whole show from what I have heard on this forum.

Frank

 

[Art Martin]

Crofter,

Thanks for sharing your well thought out conclusion. My conclusions come from over fifty years experience of cutting wood fiber. This experience comes from using chainsaws, speed chopping axes, and sharpening and using crosscut saws. Now that I no longer compete, I do enjoy helping people to achieve their goals, as Sawracer, Rupydoggy, and Rotax could attest to. I have nothing to gain by trying to sway a certain issue in one direction or another. It is frustrating when a certain issue becomes redundant and no headway seems insight, such as skip link and full compliment chains and top plate angles and depth gauges, etc.

Art Martin

 

[Crofter]

Yah its too bad its so near impossible to find an honest sawman that could judge a contest and put something like the old skip vs full comp to rest forever. I was going to suggest someone like Gyppo but gee I don't know; anybody out there attest to his honesty regarding saw statistics.

Frank

 

[Kneejerk Bombas]

I sure would like to understand this.
Can you be more specific as to what angles change?

Does the tooth rock back as it cuts, that is, does the front lift off the rails until the depth gauge hits the wood? Is this what changes the angle?

 

[Fish]

Llamabert is as pure as the driven, yellow snow.
You have opened a nasty can of worms, as John's objectivity
is unquestionable. May God have mercy on your soul.
He may be a rogue, but he is honest and impartial.
Fish

 

[Art Martin]

Mike Maas,

When I start my series on racing chains, I will submit a picture of how the optimal cutting angle works (if I can figure out how to do it). That will be on the continuing heading "ART MARTIN: will the real logger please stand up".

Art Martin

 

[Rotax Robert]

Crofter,

You send me any 91 driver 3/8 .050" chain of yours and I will test it against My Art martin chain as well as my own. I will keep it fair (same power-head & bar) I would'nt hesitate to say that your chain beat Arts, but untill you or somebody else produces a chain that can and prooves itself, I will stay with my Martin Race Chain.

 

[Crofter]

Rotax Robert

A solid endorsement for Art Martin. No, I sure won't be sending you any chain to compare to his. I am a learner, and that is not mere false modesty. It is hard sometimes to know what works and what doesn't without duplicating a lot of things that fellows like you and Art martin tried and discarded years ago. As Art said it gets aggravating when people keep coming back with such authority stating things he knows are B.S. I am posing questions with an open mind that I hope will be valuable to others as well to see answered. When I spoke of the difficulty in findng an honest saw man to judge anything I was joking slightly! It is difficult though to control all the variables in a comparison of different components or methods. People do get emotionally attached to their opinions and it can cloud their objectivity, but when fellows the like of yourself, Art Martin or Ken Dunn speak, we know the thing has been tried and proven; people listen and learn. Thats what this forum is all about and I hope we can have some fun doing it.

Frank

 

[Del_]

Flashback!

 

[pioneerguy600]

Flashback!

Those were the real interesting days of this site.