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Tutorial: make your own raker depth gauge supported by software tool

Discussion in 'Chainsaw' started by hannes69, Apr 20, 2018.

  1. hannes69

    hannes69 ArboristSite Operative

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    So, I found some time and analyzed the Carlton material (the chain manual containing the excerpts shown by PogoinTheWoods).
    What shall I say, Pandora´s box is opened ;)
    I read all of it in the hope that it makes some things regarding raker depth clearer, I clearly failed.
    They mention many things that feel correct to me, many things that are out of question. But concerning important points they stay very vague, deliver misleading information and in my opinion even make mistakes, confuse some things, mix up some things.
    That´s my opinion; either they are on the wrong path sometimes, or I am too stupid to understand what they try to say.
    So into detail (once more ;) ) :

    cuttersinthewood.jpg

    Carlton shows this image in order to explain how a chainsaw chain works.

    "As the cutter enters the wood, the leading edge starts to bite (#1) causing the cutter to rock back as far as the depth gauge will allow (#2)
    The cutter is now in the attack position.
    The cutter jumps off the guide bar and into the wood (#3).
    [...]
    The actual function of the depth gauge is to determine how far the cutter will rock back in position #2 and ultimately how large a bite the cutter will take. Also, it is normal fo the depth gauge to sink into the wood under certain conditions as illustrated in positions #2 and #3."

    So far the quote.
    When reading this and looking at the pictures, this all sounds plausible and right to me.
    But when you take a closer look and take Carlton by the word, it´s not so clear anymore to me.
    #1: Ok, the cutter sits on the rails, the chain is running, we move the saw to a piece of wood, the cutter´s leading edge touches the wood.
    #2: The leading edge pierces the wood a little bit, the cutter 'hangs', the chain moves further, so the raker side lifts up = the cutter rocks back. The end position after #2 is called 'attack position'. The raker sinks into the wood as well "under certain conditions".
    Questions to answer: How deep pierces the cutter? How deep pierces the raker? What are 'certain conditions'?
    #3: Ok, the chain moves further, the raker can´t pierce deeper anymore, the cutter can because it´s sharper than the raker. The raker was already in the air after #2, now the leading edge bites more and the cutter side lifts up as well, whole of the cutter jumps off.
    Questions to answer: How far jumps the cutter? Horizontally like in pic #3, more, less?

    I accept the principles they´re showing here and maybe they reflect reality. #1 - #2 - #3 is a black box though. We know that this all happens 'more or less' as shown, but we don´t know exactly.
    It surely depends on raker depth, sharpness of the cutter, chain speed, saw power and torque, chain tension, cutter shape, wood type,....
    What´s my point: I don´t think we can quantify here anything. "All depends on everything..."

    Later on they mention 'guesswork', 'constant method' and 'progressive method' as methods for raker depth filing.
    They explain WHAT the constant method is, they say THAT this method is not recommended, but they really don´t explain WHY at this point (they say more or less it´s bad because it is constant).
    Then the same argumentation for the progressive method. They say "this means simply that the depth gauge setting changes with the length of the cutter", that this is recommended and the FOP can do this.
    Hope comes up, "it will be fully explained on the following pages".
    Now comes the excerpt given by PogoInTheWoods.
    And now things start to get really strange for me.
    They ride and ride upon the 'hinge point' thing. And try to explain THAT there is a problem with it, THAT the FOP takes care of this problem and HOW the FOP takes care of this problem. And as a consequence this all means that the FOP is a better raker depth tool than a constant one or eyeballing.
    Once again the illustrations:

    hingepoint.jpg
    Look carefully!
    There obviously is something very wrong and not an unimportant one!
    So there´s the hinge point. Yes. Like shown above, the cutter rises up on the raker side, turning around the hinge point, which stays on the guide bar. Like in #2 above, they let the raker rise up exactly as high as the leading edge of the cutter, so that both points have the same height above the guide bar.
    Now look at the pics above: On the left side a new cutter, on the right side a more than half worn cutter. They claim both having a raker depth of 0.027".
    Fake news ;)
    You can prove, that the two explained points have the same height on the right cutter. And you see that the left and right cutter have the same 'attack position'. That is not possible.
    When having the same raker depth and the same height for raker tip and cutter tip related to the guide bar, then the attack position on the right side would have to be lower than on the left side (more attack on left side).
    So how can this be? Very simple: Look at the right picture. Obviously the cutter on the right side has NOT the same raker depth than the one on the left side. It has a way lower raker, the one a progressive gauge like the FOP produces when the cutter is filed back.
    They argue against themselves at this point!
    Further down they say: "The theory behind the progressive method is, to increase the depth gauge setting as the cutter is filed back to compensate for the fact that as the leading edge crosses the hinge point of the rear rivet it will tip up less than when new and eventually will tip away from the wood". What a monster of a sentence...
    And clearly wrong in my opinion.
    It´s the other way round. The more depth gauge you allow (lower raker), the more the cutter can rise up, the more agressive is the 'attack position', the more the leading edge of the cutter gets more and more towards the hinge point.
    So towards the end of the chain´s life a 'decreasing' / left alone depth gauge setting would help to stay away from the critical 'hinge point', not an increasing one!
    What I think the truth is, and I don´t get it why they didn´t show it that way: "A progressive gauge maintains the 'attack position' during cutter wearing. A constant depth gauge leads to a 'attack position' with less and less attack during cutter wearing. Towards the end the progressive depth gauges lead to a slightly decreasing 'attack angle' by its design, which is desireable because of the 'hinge point' argument."
    Very interesting: Further down in the text, they show cutter #1, #2 and #3 in their normal position, they don´t compare the three ones in their corresponding attack position. You now know why, you would detect the fake.
    Strange approach, the hinge point thing. They didn´t use the true argument with the maintained attack angle and on the other side they tried to show the FOP´s strength dealing with the hinge point, but obviously it´s the other way round than they showed it.
    And BTW: I only showed now their wrong argumentation. Another problem is the hinge point concept itself. If this is really true, what does that mean?
    Clearly there is a usable part of the cutter towards the end of life point, that sits already behind the hinge point with zero attack position. And there is a part of the cutter near the hinge point, which goes behind the hinge point even when having only small attack. In their argumentation this now means that maybe the last quarter of the chain can´t be used, because the cutter tip goes behind the hinge point and tips away from the wood. I don´t think that this is the case in reality.
    Strange. In my opinion their manual has so much truth in it, many things are explained extra ordinary well. And especially regarding the rakers, they chose a very strange (and in my opinion wrong) argumentation, leaving out the real advantage of a progressive approach.
    I suspect the following: They wanted to show something that you can easy comprehend by a figurative manner. They chose the analogy of the 'see-saw' by purpose. So you can imagine something.
    In their explanations they only speak of 'depth', they never speak of 'angles'. Maybe they think that an angle is a more complex 'item' than a distance?

    My point here is not to bash Carlton. My point is, that we probably won´t be capable of quantifying something at this point.
    I have the feeling that we stay in the empirical corner here.
    It seems rather difficult to explain and quantify 'why EXACTLY' a constant cutting angle concept may be more appropriate and better working than a constant depth concept.
    Carlton at least couldn´t convince me ;)
    That has to do with the pictures above #1 - #3, the black box. Too many variables. I don´t think that it is possible to find out more with my / our methods. Maybe complex computer simulations with many parameters and variables could help. And lab tests under controlled circumstances.
    I personally kicked in, like I said several times, at a certain point not questioning the past.
    For me a constant angle approach seems to fit and work in reality, so I personally aim for (rather) constant angles.
    I own a worn out chain on its limit, I filed down the rakers according to my gauge type 2, it works.
    And I never heard some of the 'real constant angles - DAF' party complaining about a chain not working because of the hinge point problem.
    Best quote of Carlton´s manual regarding rakers: "The most misunderstood part of a saw chain is the depth gauge". Yes. That was even proved by themselves....
    So if even Carlton is not able to explain that stuff right, how could I ?
    So I stay by purpose with the 'my preference' approach.
    "I use method A because it works better for me than method B. I don´t fully understand why method A is better than B, but if it works better for me, maybe I don´t care that much about the 'why' ".

    Maybe someone of you can bring light into my darkness... As I said, maybe I simply misunderstand Carlton´s point here.
     
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  2. HarleyT

    HarleyT Tree Freak

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    I always knew that those bastards were totally corrupt!!!!
     
  3. HarleyT

    HarleyT Tree Freak

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    Keep fighting the "GOOD Fight"!!!!!
     
  4. 46 Poulan

    46 Poulan Addicted to ArboristSite

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  5. Westboastfaller

    Westboastfaller Addicted to ArboristSite

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    I'm stumbling on you post, WTF happened to "litle bits"lol

    I'll make one point
    ..OK they start with the perfect design (New Chain) If they 'could' match the cutting angle degree from new, to the rivot, they would! ..or why would they make it that way?Unfortunately they have a cutter getting lower, as well retreating back from the driver. Then they have a third change as the angle changes through the raker slot. Its impossible to duplicate what they started with, without losing the simplicity, among other things.
    Sure they could have an extendable as well a few plates you slide up with your thump to bump the height on the tooth. It would be pretty easy yo make but It would be like surgery for most to use. Carlton said 45 thou is the max their gauge can do. Stihl was at 42 thou. I believe Calton said either
    58 thou or 63 on the back of the rivot?. I suppose it's 'better',
    Beter for them if the chain is 'under- rakered' at that stage of its life.
     
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  6. hannes69

    hannes69 ArboristSite Operative

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    Yes, the whole topic of 'maintaining the correct raker depth' and whole of this thread here is a :drinkingcoffee: topic. Maybe we should move it more in the direction of :givebeer: or :drinking: ??? Aaah, forgot it, that´s HarleyT´s job already :)
     
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  7. hannes69

    hannes69 ArboristSite Operative

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    "little bits" was yesterday, today it´s time for the "full load" ;)

    I´m not so sure what Carlton exactly tried to achieve. I mean, what they REALLY tried to achieve and not how they tried to explain it. I assume in reality they tried to maintain the cutting angle / attack position and for strange reasons they decided not to communicate that point but focused on the side stage of 'hinge point'.
     
  8. Westboastfaller

    Westboastfaller Addicted to ArboristSite

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    My buddy had a saw shop and they sent out all that stuff.
    They are well versed in "The Kiss method.
    Its all about covering your azz too.
    They have more scare tactics than Dr Oz..lol
    As I said, a lot of emphasis on going easy on the rakers and hook as they said it would pound your rails out. and is dangerous (true) " The worst of both worlds" doing it together was their words. They want to see text book filing. 10° up into the leading edge.
    Of course a simple analogy to send to shop owners to pass on to customers. Its simple to understand. They say the progressive will work 100% but that's only to the pivot and that where the expectations stops on that chain.






    Hannes said:
    "I read all of it in the hope that it makes some things regarding raker depth clearer, I clearly failed."

    ∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆
    Regardless of what you get out or it,
    Targeting either hardwood or softwood gauge cutting angles is correct up to the neutral position of the cutter pivot anyway.
    It doesn't confront your original objective, as that was using the full chain with even teeth.
    As I said in one of my first post after I understood the mechanics of how your gauge worked and that was, you could free hand a few extra flat strokes at that point.
    I never really paid attention to the last three read outs of your data anyway knowing I would have uneven teeth.
    I'm sure they said its about double (0.63 thou is what I remember?). that would be needed on the 'back of the rivot'. Assuming that's a soft setting. I did an estimation on where I thought was the neutral position of your read out and it looks to be about .053 for hard. Unofficially but it's double +3 on each.
    You can figure out what it really is. What is 005" difference on the gauge between hard and soft setting is in reality, .010"+ on the chip difference.

    In short: A new chain will set at it's raker depth and dive an additional 100% over its depth in attack mode (About 1/16" chips. In total. The only place where there is Zero diving is the pinical pivot point (Neutral) where " gauged cutting angle" and attack cutting angle are "one of the same". In reality 100% gauge chips vs 0 attack chips

    ^^^ Edit on end
     
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  9. Philbert

    Philbert Chainsaw Enthusiast

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    What is your opinion of the depth gauge profile? Is it included in your software calculations or assumptions?

    (I will try to make this post as long as possible to fit in the spirt of this thread).

    Most chain is manufactured with rounded cutters that will slide across the wood at any angle of contact. When people file or grind the depth gauges flat, it can create a sharp point of contact, with may dig deeper into the wood; increase drag; or act as a leverage point, effectively working as a higher depth gauge.

    Most sharpening guides will say something like, "after adjusting depth gauge height, round over the depth gauge to match the factory profile". But a lot of guys don't.

    (add some random text here to make this post long enough for this thread).
    .
    .
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    .
    .
    .
    .

    Philbert
     
  10. PogoInTheWoods

    PogoInTheWoods Don't forget about the alligators...

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    Wouldn't that typically be when using a grinder or fixed depth gauge tool that indeed leaves a flat depth gauge?

    I don't worry about the 'profile' with a progressive adjustment tool as the angle of the tool determines the profile, albeit still a 'flat' one, but at the angle of the tool. I personally wouldn't waste time going back over every depth gauge again just to give it a rounded front when using a progressive tool for the adjustment. Plus, one bad swipe with a file affecting an already perfect raker height and you'd hafta shorten the tooth to match, and then shorten every other one to match, and then...
     
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  11. PogoInTheWoods

    PogoInTheWoods Don't forget about the alligators...

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    Rounded cutters?
     
  12. Westboastfaller

    Westboastfaller Addicted to ArboristSite

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    Hannes quotes & talks about Carlton" theory below.....

    ...."The theory behind the progressive method is, to increase the depth gauge setting as the cutter is filed back to compensate for the fact that as the leading edge crosses the hinge point of the rear rivet it will tip up less than when new and eventually will tip away from the wood". What a monster of a sentence..."

    Its a monster of a statement because its doesn't just happen entering the neutral zone, its not in preparation for that moment... Lol
    It's compensating the whole time. From the second file.


    "And clearly wrong in my opinion.
    It´s the other way round. The more depth gauge you allow (lower raker), the more the cutter can rise up, the more agressive is the 'attack position', "

    Poorly worded as I pointed out but they are saying the same thing "increase the depth as cutter wears back"?? No??

    the more the leading edge of the cutter gets more and more towards the hinge point.
    So towards the end of the chain´s life a 'decreasing' / left alone depth gauge setting would help to stay away from the critical 'hinge point', not an increasing one!

    IDK something poorly worded again? Technically yes but it still needs more raker.
    As a decreasing raker is not an option as it finishes at 100% raker cut.


    What I think the truth is, and I don´t get it why they didn´t show it that way: "A progressive gauge maintains the 'attack position' during cutter wearing. A constant depth gauge leads to a 'attack position' with less and less attack during cutter wearing. Towards the end the progressive depth gauges lead to a slightly decreasing 'attack angle' by its design,

    Over thinking it. What was their choice man? They don't have a choice
    Its a flat plate on an angle with things changing. Its not a perfect system and its not superior. Don't even entertain that idea, its ridiculous."
     
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  13. Philbert

    Philbert Chainsaw Enthusiast

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    Big assumption.

    Off by a fraction of a degree, and the leading edge catches on a sharp corner, instead of the flat.

    Plus, the cutter rocks in the cut, so the depth gauge will make contact at different points through the cut.

    Philbert
     
  14. PogoInTheWoods

    PogoInTheWoods Don't forget about the alligators...

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    OK. What am I missing? And what is being assumed?

    I would contend that attempting to round over the leading edge of a depth gauge has a much greater probability of being 'off' by a fraction of a degree than simply filing in a diagonally downward fashion along the specific angle established by a progressive type tool..., in reference to the cutter, of course.

    Just arbitrarily rounding off the leading edge of a raker with no reference point whatsoever provides nothing even remotely resembling precision within 'a fraction of a degree' in the resulting profile.
     
  15. Westboastfaller

    Westboastfaller Addicted to ArboristSite

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    Hannes continued........
    ......
    "I accept the principles they´re showing here and maybe they reflect reality. #1 - #2 - #3 is a black box though. We know that this all happens 'more or less' as shown, but we don´t know exactly.
    It surely depends on raker depth, sharpness of the cutter, chain speed, saw power and torque, chain tension, cutter shape, wood type,....
    What´s my point: I don´t think we can quantify here anything. "All depends on everything..."

    Yes a lot of variables, as it was just said the shape, they will also chatter if they are flat and badly affect your depth when they get very flat, low and long. Its why it's a lot of work when they get low.

    Another point, with the dogs, the chain can't come off the bar.
    With the longer bars you can see the chain getting pulled off if its a little loose when I start an angled falling cut without the dogs. Just about a 5 inch section gets pulled out. so you get a lot of different tention throughout the bar. The ends being much tighter so this may also account for different chips and slightly different mechanics going on.
     
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  16. Westboastfaller

    Westboastfaller Addicted to ArboristSite

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    its a different angle.
    Anyway I always do that before I put the gauge on eack tooth or at least before I file so there is wiggle room.
    Kind of kill two birds with one stone as a get the material down quickly without the gauge and shape the front.
     
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  17. PogoInTheWoods

    PogoInTheWoods Don't forget about the alligators...

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    Precise 'wiggle room' within a fraction of a degree I presume? LOL

    Just when it seemed like this was getting into a more practical realm there's new hair splitting over fractions of degrees..., regarding a raker's profile no less.

    I would have thought Philbert was just tossing some levity into the mix had it not been for that large, bold emphasis about my assumption..., which I'm still attempting to determine.
     
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  18. Philbert

    Philbert Chainsaw Enthusiast

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    You are assuming the angle of contact. or at least initial contact, for the depth gauge (apologize for the crappy sketch, but I don't have a lot of time; give me some leeway on the proportions, angles, etc.).

    Your expected point of contact should lie along your intended angle, but a rounded profile will not dig in (or scrape as much) as the cutter rocks, or if it makes contact with the wood at a different angle, if the wood is soft, etc..

    'Splitting hairs' about degrees, since the discussion has been about tenths of a degree over a very short distance: lot of 'hair splitting' in there too.

    Philbert
    Screen shot 2018-05-23 at 2.58.10 PM.png
     
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  19. Philbert

    Philbert Chainsaw Enthusiast

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    Spoke with an Oregon engineer once, and he told me that the average user would not believe how far the cutters get pulled out of the bar groove during normal cutting.

    Philbert
     
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  20. PogoInTheWoods

    PogoInTheWoods Don't forget about the alligators...

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    I believe the initial angle of contact is determined by the adjustment obtained from using the tool as intended..., (be it a point of an angle or a tip of an arc) at the highest point on the depth gauge allowed by the tool. No assumption there. Whether or not the desired functionality is obtained can certainly be assumed to be dependent on many factors having far greater influence than the arc (or angle) of the depth gauge. I'm not arguing that the arc on the leading edge is irrelevant, but rather just not as critical of a parameter to fret over when using the progressive style tool since it creates its own degree of 'wiggle room' by the very nature of the angle used to adjust the depth gauge in the first place. Fixed tool adjustments would most definitely benefit from some shaping to the leading edge of the depth gauge. No question about that.
     

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