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Post by chainsawwhisperer on Oct 24, 2008 5:54:51 GMT -5
Can anyone give some clarification on these statements from the Madison's PDF:
1. "Most 3/8” pitch chisel chain is supplied in a round ground configuration, but for racing most competition cutters convert it to a square ground configuration" Isn't it supplied in square ground to begin with?
2. "This discussion is based on using the 72LP style chain, which is produced with guard drive links for kickback control. Generally, competitive operators we have seen remove the upper ramped portion of the guard links by grinding or filing them down to the top of the tie strap" What's the advantage to starting with a chain with guard links if your just going to grind them off? What makes 72LP chain that much better? Why not start with non guard link chisel chain?
3. "After sharpening the cutting edge, the depth Gage setting is adjusted for the material being cut. See Table 1"
The table states: .017 and .020 respectively for hard wood and soft wood. On woods chain I've always heard .025 and .030 respectively for hard and soft wood. Is the shallower cutting to keep the RPM up?
Any ideas?? CSW
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Post by RandyMac on Oct 24, 2008 6:22:56 GMT -5
It does seem rather odd not to pick square filed to start with, and "safety" chain? The high rakers kinda makes sense with high speed, low torque motors, too much of a bite would bog them out.
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Post by chainsawwhisperer on Oct 24, 2008 10:27:48 GMT -5
.025 does not bog stock saws. I'm thinking it was a typo, or done purposely to limit there liability. CSW
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Post by woodplayer on Oct 24, 2008 20:46:56 GMT -5
Can anyone give some clarification on these statements from the Madison's PDF: 1. "Most 3/8” pitch chisel chain is supplied in a round ground configuration, but for racing most competition cutters convert it to a square ground configuration" Isn't it supplied in square ground to begin with? CSW- The Oregon square ground "CL" style chain is the "LG" style, which does not have the guard link. (That's how mine came) However for a faster chain the "LP" style with the guard link is preferred.2. "This discussion is based on using the 72LP style chain, which is produced with guard drive links for kickback control. Generally, competitive operators we have seen remove the upper ramped portion of the guard links by grinding or filing them down to the top of the tie strap" What's the advantage to starting with a chain with guard links if your just going to grind them off? What makes 72LP chain that much better? Why not start with non guard link chisel chain? If you look at the "LG "style, it's depth gauge is quite large, wide and bent sideways. The "LP" style depth gauge is much slimmer/narrower. So by grinding the guard link on the"LP" style you have a faster chain than the "LG" style If you clink on the LG and LP links on this page you can see the difference in the depth gauges from the side, but what you can't see is the width difference when viewed from the front. www.oregonchain.com/38.htm3. "After sharpening the cutting edge, the depth Gage setting is adjusted for the material being cut. See Table 1" The table states: .017 and .020 respectively for hard wood and soft wood. On woods chain I've always heard .025 and .030 respectively for hard and soft wood. Is the shallower cutting to keep the RPM up? I believe you are correct,CSW, on the RPM. I don't think many of the older reed valve torque machines are used in racing, so you want the RPM's kept high.
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Post by bruce hopf on Nov 6, 2008 19:47:40 GMT -5
Zip "I guy on AS last year posted that he filed his chains with a file that was 1 size smaller than recommended. This gave him more 'hook' He claimed his chain cut great, but I think that durability of the edge would be an issue." Typical AS misinformation The only time I used the next size down, is when the chain is nearly used up. You are correct, more hook means the edge will fail sooner. When I used to file my Chains, 3/8 Pitch Chains called for 7/32" Files. My Great Uncle, my Dad, and I always used 13/64" Files to Sharpen our Chains, right from new, and never had a problem with the durability of the edge. Did it that way, for as long as I can remember. For the Past 6 Years, Ive been using a Bench Grinder to Sharpen Chains with. Thanks. Bruce.
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Post by bruce hopf on Nov 15, 2008 6:37:08 GMT -5
I think that if you want a really fast chain there will always be the trade off of dulling quicker. I tend to use the semi chisel type chains for dirty cutting and chisel for clean. I have just picked up some square ground chisel that I will be trying out shortly. For either the round filed semi chisel or round filed chisel, my understanding is that to make it cut quicker (again will depend on type of wood you are cutting) some of the things you can do include: 1. increase the top plate angle ( say from 25 to 30 or 35 degrees), 2. tilt the file slightly upward (compared to a flat position) 3. using a slightly smaller file or try dropping the file lower into the cutter (effectively decreasing the side plate angle, or making a hook) These will all make the cutter edge smaller/slimmer and the chain may cut faster. Also ensuring that the gullet area is cleaned out will help with chip removal and a chain cutter that has been filed back may help. (imagine the cutter filed back to about 1/3 of the life of the cutter). Cleaning the chain before filing as well as cleaning the file occasionally during use may also help. Most of the other forums have sections on race chain etc. however the following link gives some basic details on race chain www.madsens1.com/pdf/RacingTechfacts_93099.pdfI may be going out on a limb here, but I have a feeling that the older slower running torque saws could have the depth gauges slightly lowered and with a square filed chisel on a new high revving peaky saw, it may actually help to keep the depth gauges a little higher. Square filed chisel is filed from the outside of the cutter to the inside which also does not leave a bur on the outside plate. I'm not sure if doing this would help with round filed chain. The only experience I have with chains ground with a grinder, is on new factory chains, however I do know that if I use a bar mounted chain filer the chain can be made much sharper than the factory grind, using the same angle etc. It seems the file is a finer grind than a grinder. I modified a bar mounted filer to accommodate a square file which I will be trying once I make some cuts with the new square ground chain I just got. It took me a long time to duplicate the factory grind angles (I tried a little filing on a couple links of the new chain), and now that I have the approximate settings it will still take much longer than filing with a round file. Here's a photo of factory grind and my bar mounted filer. Unfortunately I don't have any machining tools, so I was stuck using only my drill press and sander to build the aluminum holder pieces. I'm sorry but I have to disagree with you about the Degrees of the Top Angle of the Cutter. Yes at one time, the Cutters of a new chain, were cut at 35 Degrees, right from the Factory. These were Cut this way, for Mainly for the Pulp Wood, and Soft Lumber Industry. When we sharpened them, we always set the Filing Guide to 30 Degrees, for a Narrower Cut. Especially in Hard Wood. With the Cutters cut at 35 Degrees, you have a Wider Cut Path. The lower you go in Degrees, from 35 Degrees, the Narrower the Cutting Path of the Chain, and less power you need to use to run the Chain As Well. For Cutting in Hard Wood, the Narrower the Cutting Path, the Better (Nothing less than a 25 Degree Top Angle, or you will be too Narrow for your bar, and Chain to pass through what you are cutting). Now cutting Soft Wood, such as Pine, or Ever Green, Pulp Wood, or something like Bass Wood, is a Whole Different Animal. Then you want to have a higher Degree of your Top Angle on your Cutter, because of Binding Issues you can run into with your Chain, and Bar, so the Wider your Cutting Path of the Chain, the Better For cutting these Woods, I have heard of guys that Cut these Woods all the Time having the Top Angles Sharpened at 40 to 45 Degrees. Another very Key thing to realize, is the Height of your Rakers, or Depth Gauges of the Cutter, is to have them cut down every once in a while, to what ever Specs you desire, and to make very sure, that they are all set equally. If they are un evan, this could also slow down your Chain and take more Power to run the Chain. Bruce.
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Post by RandyMac on Nov 28, 2008 5:20:18 GMT -5
I don't know race chain, but I am a saw filer's son.
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Post by bruce hopf on Dec 2, 2008 18:34:38 GMT -5
Look at it this way. If you have been sharpening your Saw Chains, and have had good Success in the Past, Why Change the way you are doing things. A 3/8" Pitch Chain calls for a 7/32" file, to Sharpen with. There is nothing wrong with this what so ever. Now for the Guy over at AS, that said that he sharpens with a File that is one Size Smaller, does in fact work. Over 30 Years now, my Great Uncle started filing his Chains with the aid of a Filling Guide, that mounts on the Guide Bar, with a 13/64" File, that was one size smaller than the 7/32" what was recommended. It did cut a little more aggressively, as I remember him explaining to my Dad, and my Uncle. I have never tried to see if it was true or not, but I in fact was taught over 25 Years ago by my Dad to sharpen my Saw Chains with a 13/64" file. Up until 8 years ago, I always sharpened my Chains with the same sized file, then I got myself a Tecomec FL 136 Bench grinder, and have sharpened my Saw Chains with it since. Until I started joining Chain Saw Discussion Forums, I never knew that I was using a File one sized Smaller than what was recommended, a 7/32" File. As I have learned, there is no wrong way, or right way to sharpen a Saw Chain, but the End Result must be the Same. Every Cutter should be as close as possible to the same Degree of Angle, same Pitch, and the Rakers should be as close as possible to the same Height. All these put into play, you know that you will be able to go out and Cut Fire Wood, or what ever you do with your Chain Saw. What ever way you decide to Sharpen your Saw Chains with, is up to you, and what ever you are Comfortable you are with, as long as it works for you, and if you get Full Use of your Chains, until you can't sharpen it any more because you are down to the Safe Sharpening Point on the Cutter, you know you are doing a good Job of Sharpening. If you are only partial through your Saw Chain, and it Cuts Like Crap, then and only then, you should be looking at your Saw Chain, and figure out what you have been doing wrong, before you put a new Loop of Saw Chain on your Chain Saw, and also study the Rails on your Guide Bar. If one of your Rails is Narrower on one side of the Guide Bar, that should be a dead giveaway, that you are doing something wrong, and do not have the Same Degree of Angle on your Cutter, as well as the wrong Pitch of your Cutters from one side of the Saw Chain, to the other. Remember that anyone can File a Saw Chain, but can they do a good job of Filing a Saw Chain. There are two Answers to this Question. Yes, and there is No. Hope this helps. Bruce.
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Post by RandyMac on Dec 2, 2008 20:41:53 GMT -5
you pretty well said it Bruce, if it works for you and you can do it the same everytime, you have it.
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