What Makes a Chain Cut Fast?

[Crofter]

I have spent a bit of time over the past couple of years digging into what makes for a fast cutting chain. What is a good fast cutting work chain really does not have a whole lot in common with what the boys put on their saws for competition. It would be like comparing a Mack truck and a Ferarrari.. Still the need for consistancy and attention to detail pays off. I took some pics of cut surfaces of cookies and the porpoising intermittent cutting action seems to show in the cut. The cut that looks rough by comparison is a square filed chain that is considerably faster than anything you get out of a factory box. The other chain is one I have been toying with and is faster. I almost think the cutting action changes and some different effects come into play. This is the kind of elusive exercise I find interesting even if it makes MasterBlaster and Glen yawn. The wood is hard maple.

 

[DirtTroll]

If I had a butt load of torque, I could make lighting fast semi-chisel chains with minimal effort. Just remove the chain depth rakers. But unfortunately the saw torque requirements would be huge. From the pictures it looks like you did this to an extent, but it also looks like you did not even the depth rakers up (inconsistant cutting).

 

[Chopwood]

Try some softwood Frank, I'd like to see some times. Looks great

 

[Mange]

About time!

I do not know where to begin.....
Great pics Frank!!!!!!!
I have been tinkering with the filing too, trying to get a grip of this bad a$$ subject. After countless hours hand filing (round file), I am starting to get a grip of the subject. Or to be more precise, I am beginning to understand I have much to learn yet.....
The conclusions I have come up with is a bit surprising..... I round file first, then ever so gently touch it up with a square file?!

The chain that cut smooth in your pic was it round filed semi chisel or chisel?

 

[klickitatsacket]

Here is a picture of a custom chain. The customer wants this 36" loop ground for $4. He said it was getting hard to cut with. HMMMM?????? I will have to run it through in 3 stages just to clean it up.

 

[kf_tree]

Here is a picture of a custom chain. The customer wants this 36" loop ground for $4. He said it was getting hard to cut with. HMMMM?????? I will have to run it through in 3 stages just to clean it up.

are you serious? that chain is shot, i toss better looking chains than that all the time. if you sharpen chains like that for 4.00. please let me have your address so i could fill your mailbox with chains that were run in the ground, hit metal, rocks, concrete etc

 

[Crofter]

Klikit; you can see from the chain rails that it took some pushing to make it annoy the wood! You got some work ahead of you. Just hope one side of rails not wore more than the other.
Mange; both are square filed.

 

[klickitatsacket]

I do not like to do a lot of chain like this, but it does good to do it for some of the guys who are a little hard up. It's good PR and pays off when a guys bring the old saws and gives them too you. I usually tell them to bring them in a little sooner, but I know they can't afford it. I keep a lot of used bar and chain around for the same guys. It usually is a guy that is on a fixed income and heats his house with wood. These are also good for the kid that comes in after school to learn on.

 

[Mange]

The costumer is always right. He want it done, then do it.

Crofter.

I have done a test.
3 chains all same kind filed with round file, with same depth, One does these carvings, the other to is ruff compared to yours.
The smoothest is filed with a flat file after round file.
They cut just about the same, but I had a bit hard wood I think to get a fair judgment, Dry English Elm.

I think I got the corner angel wrong, but it looks ok, and is correct angles

I will test them in a softer wood when the opportunity appear.

 

[Lawn Masters]

I need to come up there and have some fun. Lovin those square ground chains. gotta learn how to do that myself too.

 

[Crofter]

I am not suggesting that a really smooth cut like that is good for a working chain that has to cut a kerf much wider than its bar to be usefull to a person in everday conditions. A chain for competition will look entirely different though and cut a much narrower kerf. I think that if a chain is going to be fast it should not waste a lot of horsepower making notches and grooves in the end grain of the kerf. When the cutter slices thru the wood very easily it does less jerking around like a fish on a line. Your chain is like 30 or more fish or kites all on the same line. Uniformity of action from one to the next makes a big difference in how they behave and jerk each other around.

 

[Mange]

So if it cut like that it is not correct. Differance in angels or length of teeth?

If it is smooth then it is correct? The more precise the smoother etc.

 

[Mange]

Please tell more!
I want to learn!!!!

 

[Crofter]

Uniform raker clearance is important too. The smoother cut had less clearance and the saw was able to hold a higher rpm in the cut. I am guessing each of the cutting strokes of a tooth was longer and shallower so the chain had a different vibrating motion. When a cutter dives into the wood, the angled top plate and its resistance to penetration forces the tooth laterally and the engagement of the side cutter also tries to make it dig into the side of the cut. It cuts wider kerf than its own width.If you have a low raker or a long tooth, not only does it take a deeper chip, it cuts a wider gouge out into the end grain or side of kerf. This causes a jerk that affects other teeth being pulled on the same chain. This explanation is just my interpretation not gospel! I certainly welcome discussion or another way of explaning what goes on in a cut.

 

[Mange]

Well, I for one will sing along that gospel!
Sounds right to me.

I go file now!

 

[Kneejerk Bombas]

It's not clear what the differences in the cutters are that made those two cuts. If I had that information, I could theorize why the difference appearance.
Are you getting to the point where you are developing "trade secrets", and don't want to give away hard earned information?

 

[Crofter]

Hey Mike, work that from the other direction. What would you think necessary conditions to produce the two different patterns.

 

[ehp]

If you want a fast chain just buy one from the WORLD FAMOUS GYPO LOGGER, I am now his dealer for the North America section, and with every chain you will get a signed picture of this famous man, what more could a man want

 

[eyeinstine]

If you want a fast chain just buy one from the WORLD FAMOUS GYPO LOGGER, I am now his dealer for the North America section, and with every chain you will get a signed picture of this famous man, what more could a man want

Uhhh. The picture will be with him clothed, correct?? I still cant get the horrendous visions out of my head from some of his prior self portraits..

 

[Kneejerk Bombas]

Hey Mike, work that from the other direction. What would you think necessary conditions to produce the two different patterns.

Either a blunt outside top-plate angle or a very sharp inside side-plate angle would allow the cutter to flop back and forth, is my guess.
One of the problems with a steep outside top-plate is it drives the cutter toward the wood and creates drag (power loss and wear on parts). This would cause the cutter to stay positioned to the outside, making a smooth cut though.
I would also think the inside side-plate could have the same effect.