Art Martin: Will the Real Logger Please Stand Up

[Art Martin]

Ryan,

The 056 pulls a 28" bar easily with a 7 point sprocket with the rakers set at .025". When I worked in the woods, my last saws were the homelite 900 series, both gear drive and direct drive.

Art Martin

 

[Ryan Willock]

Art, what year did you retire from the woods??? why did you choose homelight over stihl? where they higher quality at the time?? just wondering. thanks:angel:

 

[Art Martin]

Ryan,

Where I lived in Fort Bragg, CA, there was not a Stihl dealer at the time that Homelite was on a tear. They were really pushing their produce and gave us demo saws to test on the job. Then a new dealer bought out the previous dealer and I became good friends with him. He was a former chainsaw champion and took me under his wing and taught me a lot of secrets on how to make speed cut, dechroming chain, lightening chain, custom made sprockets, grinding speed cutting axes, hot fuel, and much more. My winning ways sky rocketed and it helped his business because of the publicity we got competing all over the state. I retired from the woods and went into the fire department in 1963 but started competing heavily after that. I worked for the Homelite dealer In the San Jose on my days off and was sponsored by Homelite.

Art Martin

 

[don]

Wow that is so neat to here about your early adventures

how to make speed cut, dechroming chain, lightening chain, custom made sprockets, grinding speed cutting axes, hot fuel, and much more

So seriously Art you should publish a book on your adventures and methods for various wood working methods.

 

[Ryan Willock]

Art, don is right. your story should be a book as it is very fasinating and alot of fun to read!!!:angel:

 

[HomeDelight Man]

Nothing like a 900 series Homelite!!

 

[Art Martin]

Many people have often asked, “why is the round filed chipper tooth chain not as fast as a square filed chisel tooth chain?” I know the answer and will make an attempt to explain it, but after reading the other thread, “top plate angles” I just wonder, why bother, people just don’t seem to get it, but here it goes anyway.
The chisel tooth chain incorporates a flat top and sides, which meet at a square outside corner. This makes them the ultimate in efficiency, smoothness and they also stay sharp longer. They introduce more cutting edges to the wood. It’s the working corner that does all the work. The corner, being the highest and widest point on a chisel chain, meets the wood first and this starts the cutting action. The advantage of the chisel tooth allows each cutting edge to function independently as designed. The side plate severs the cross grain and establishes the kerf. The top plate removes the severed wood or chip. The flat-faced side plate introduces a straight cutting edge to the wood, allowing the entire edge to do the work. In the round filed chain, both the top and sides plates must function together. Round filing also imparts a curved edge on the cutter. This allows a smaller portion of the cutting edge to be working at any one time. A cutter, that has a radius that joins the top and sides, is considered a round toothed chain. That is called a chipper tooth chain. A round toothed chain must work a little harder to equal the output of a chisel chain. Both the top and side plates, on a round chain, are higher and wider than the corner. In this configuration, the cutter must make a few more passes to achieve the same corner position of a chisel cutter. The ratio would be close to 2 to 3, which means for every two revolutions that a chisel chain makes, a round tooth chain must make three revolutions. If all other conditions are the same, (i.e., raker settings, and the length of teeth, the same saw and bar). That would mean that for every 1,000 revolutions that the chisel tooth chain makes, a round tooth chain would take 1,500 revolutions to cut the same amount of wood. It’s easy then to figure out that a saw would also last longer with a chisel tooth chain. With my experience I believe, a similar ratio also applies to a full compliment chain as opposed to a skip link chain, even if they are both chisel bit. A full compliment chain is simply faster cutting and smoother. If less filing time is more important than wear and tear on the engine, then that is certainly the operator’s choice.

Art Martin

 

[bwalker]

Art, could you tell me what the proper angles are to round file a chisel chain like stihl rs or oregon lg? How about the angles for square chain. It seems to me like everyone has differant angles and says differant things. I was kinda hoping you could clear all that up.

 

[Art Martin]

bwalker,

I pretty well covered the angles on the chisel chain in the thread dated 11-17-02 which is the twelfth thread down from the top on page 11. Anyway since I don't use a round file, but if I was to use one, I would put a 35 degree angle on the top plate, and hold the handle down no more than 10 degrees to get a slightly thinner edge on the top plate, being careful not to get a big hook or over hang. Holding the file level also does a good job on a chisel tooth but on a round tooth, holding the file down 10 degrees more important.

Art Martin

 

[StIhL MaGnUm]

Excellent info Art if I could chisel bit as good as you I probally would'nt round file either Thanks alot for all the tips on chisel bit filing I used all your angles,techniques on a couple Carlton square chains and they cut excellent in the White Pines around here I have not tried them in any hardwoods yet but I will as soon as possible.

Thanks Again
Rob.

 

[Art Martin]

I’ve received a lot of email about racing chains since the beginning of this thread. Now is probably the best time to start talking about the different steps that are needed to take place. Although many of the modifications cannot be duplicated without special equipment that I have developed, I can assure you that if the steps are followed correctly, the cuts will drop faster. Once again, I want to remind those people who are interested in making a racing chain that you will not see as much gain if you use it on a saw that hasn’t been modified. These two elements work together, one is not as good without the other.
The caliber of engine modification depends on the proficiency, experience and expertise of the person who does the work. I’ve seen so-called modified saws that are worthless. If you spend anywhere from $300 to $600 in modification to a production model saw, you better know that the person is competent. Rotax types of saws, of course, cost up to $4,500 or more. They are different animal or breed since they are motorcycle or snowmobile engines with a chainsaw bar and chain attached, not a production type of saw. The bottom line is that if you are going to shell out that much money, you better spend a few hundred dollars more to buy a fast chain or learn to make your own.
I now basically make chains for Rotax Robert only and perhaps sharpen a few for my close friends, because I don't want that as my full-time job since I have other interests. I will be glad to answer questions or make a sample of what I use, but that could also get out of hand sometimes. The angles that are used on a chain should fit the type of wood that is to be cut. That is why it is hard to make a fast cutting chain for someone who lives in a different part of the world, and you have never cut the type of wood in their area. I have more expertise on Redwood and Douglas Fir since that was what I cut day in and day out during my first career, although the differences are very slight. There are several chain configurations available, and I have tried them all, in fact even made my own by experimenting in countless ways.
The full skip, as a racing chain was eliminated first of all because it will not cut as fast as a full complement chain, and neither will a semi-skip. For those who still want to argue the point, all I can say is I’ve been there, done it, and then moved on. The only chain that will be faster than a full complement is a custom made chain that has one cutter on either side, one after another with no spaces in between. I’ve only tested it on logs under 20”, and the saw used must be 8 cubes or over and highly modified, but it definitely has the edge over a full compliment chain.
One of the main considerations in chain modification is total weight reduction. The first concern of starting the reducing “diet” is grinding material off all the rivets. Since the rivet hole on the tie straps are counter-sunk, or funnel shaped, removing most of the head will not affect the holding strength of the rivet. Removing most of the rivet heads will gain some kerf clearance so there won’t be any drag created in that area. Removing the material off the top of the drive links that rises above the tie straps is done by a lot of people but it is risky. The reason it is risky, on a 3/8” pitch chain, is that the area above the rivet hole in the drive link has .093” of metal. If you file that area down to the height of the tie strap, so they are even in height, the metal in the area above the hole is only .040”. Very often the chain will fail at this vulnerable spot. As they say, a chain is only as strong as the weakest link. Also some people remove more metal from the end of the drive links where it transverses around the bar nose and that area of the drive link that protrudes. This also adds to the weakening problem. On a ½” pitch chain this can be done without any problem of the chain breaking, if it is run on a modified production model saw. Again, if you file down the tops of the ½” chain drive links on a chain that is used on a Rotax type saw, and the wood is harder than Cottonwood, the chain will break. Rotax Robert will attest to that because it happened to him. His “saw” has so much power that it just pulls the chain apart when under a heavy strain. A ½”pitch drive link has .115” metal on a new drive link above the rivet hole and when it is filed down to the level of the tie strap, it has .058” above the rivet hole.
To be continued.
Art Martin

 

[Art Martin]

There are several ways to remove the excess metal from the ends of the rivets. A high-speed hand held grinder, similar to a Dremel tool or a larger version, is often used. I like the set-up that Ken Dunn uses, which is a chainsaw bar with roller tips on each end. The bar is mounted in a machinist vise that is on a drill press table. There is a large abrasive wheel mounted on a spindle that fits into the chuck of the drill press. Once the correct pressure against the chain is applied with the drill press running at high speed, the chain is turned slowly by hand. After one revolution, the pressure is slightly increased to take a second bite. Finally, a third adjustment is made to finish the job. Thus, it takes three complete revolutions to finish one side of the chain. It is probably the best method and the fastest.
The next step is to grind off the front part of the tooth, back to the front of the rear rivet. I do this step with a small bench type of chain sharpener. I just set the gauge at 32 degrees and slowly grind the tooth down to the bottom of the gullet, just even with the top of the drive link. After all the teeth have been shortened to the same length, I put on a narrower grinding wheel that is used to sharpen 1/4” round chain. I set the grinder at 90 degrees and doggy-bone the tie straps between the drive links, being careful not to grind into the drive links. I even doggy-bone the area at the bottom of the gullet. I then narrow down the depth gauge by removing a portion of the front of the depth gauge and actually doggy-bone the area in front of the depth gauge. The next step is to remove the metal from the gullet. That area is removed from the backside of the depth gauge to the front bottom side of the side plate. The area that I remove becomes sort of arc shaped and in the middle area it goes down to where I doggy-boned that space. This removal can be done with a 7/32” round file or a Dremel tool with a 7/32” chain sharpening stone.
Some people make racing chains by removing the rear portion of the tooth. I did this on chains that were used in contests where you were required to bore one cut and then a straight off cut for the second cut. The back of the tooth was sloped and it really bored through the log fast, but lost time on the straight off cut. I have since modified that type of tooth by dechroming and reducing the width of the tooth to make a narrower kerf and by taking out the set to six degrees. This helps somewhat on a straight off cut.

Art Martin

 

[bwalker]

Art, I am curious as to why you take the crome of the cutters. I dont know jack about racing chains so go easy on me.

 

[dbabcock]

Art, you attached a picture! Is that the first one? Good work. I'm sure Marita had something to do with that!

 

[don]

That is a fine setup

did you use an old bar to make the rail?

 

[timberwolf]

Removing the chrome

Art, I am curious as to why you take the crome of the cutters. I dont know jack about racing chains so go easy on me.

Ben, of coarse this is for Art to awnser, but I would imagine that it is for the folowing reason:

The degree of sharpness that one can put on a tooth edge is limited by the thickness of the chrome, as the chrome layer is so hard and brittle that you cant file an enduring edge into it. The chrome often fractures presenting a broken squared edge to the wood. The steel will take a finer edge, granted it wont last long, but who cares as long as it makes it for 3 cuts.

Thanks Art, this is wonderfull juicy information, some of it can be applied to everyday life and the rest sates the imagination.

Timberwolf

 

[bwalker]

Crofter, That makes sense when you consider that stainless knives cant be sharpened as sharp as carbon steel blades. Stainless does hold a edge better though.

 

[Art Martin]

Doug,

You got that right, it was Marita who did it for me before I had a frustrated breakdown. She just followed your detailed instructions which were all Greek to me, thanks. I'm better at causing confusion with racing chain proceedure than understanding stinking computer terminology.

Art Martin

 

[Art Martin]

Don,

Any bar that has a groove that is not sloppy works fine. The second roller installed on the heel end is not really necessary but it just makes the procedure smoother.

Art Martin

 

[Art Martin]

bwalker,
There are several reasons that I remove the chrome. First, it is easier for me to make the kerf narrow with the grinder I devised, than to totally dismantle the entire chain and remove .020” off the inside lower surfaces of the cutters. Also, I alter the set of the tooth to a six-degree outward angle, which helps the chain drop down through the cut without as much drag on the sidewalls of the kerf. This is just for racing chains. When working in the woods, you need all that kerf to keep the chain from binding especially in springy timber. This is not a concern at logging contests because the cuts are thinner and the pressure from the sides is negligible.
The degree of sharpness is not a problem since I hone the outside side plate edge with a razor stone. With a filed edge, the chrome does become jagged and rough when viewed under magnification. When the chromed edge is honed it is much sharper and thinner.

Art Martin