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

[Westboastfaller]

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


.

Lol
That's just how good I am..lol
Now if I could only keep my chains running straight.

Hey, do you remember that time?.... That time when you got mad at me?
No, I wasn't serious. just tired, dry British antics. We will just call it 'dryantits' They say you can tell an Englishman,.....but... You can't tell 'em much..lol
IDK..if I've ever been ripped like that but I laughter my azz off ...every time I read it.

 

[hannes69]

They are well versed in "The Kiss method.
Its all about covering your azz too.
They have more scare tactics than Dr Oz..lol
[...]
Of course a simple analogy to send to shop owners to pass on to customers. Its simple to understand.

Okay... There you deliver a simple explanation for the given facts, and probably you are true Maybe I had a liitle bit too much respect for Carlton and didn´t consider enough what HarleyT says about them

Targeting either hardwood or softwood gauge cutting angles is correct up to the neutral position of the cutter pivot anyway.

Yeah, still my assumption

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

Hmm, can you explain this in other words once again please? Where do these numbers come from? 100% over its depth / 1/16" chips?
Chips - reminds me of one approach: I never measured chips, could be interesting

 

[hannes69]

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

Depth gauge profile has an influence on cutting performance, yes. If the profile is not on a very extreme side (angle 0° or negative angle or extreme positive angle) it should not have a very large impact.
The shape itself can´t be covered by the depth gauge tool in its simple form and of course not by my software calculations.
I´ve made some thoughts about the raker angle though.
The progressive gauges type 1 and 2 deliver a starting raker angle of 18° for a new chain and 10° for the end of life chain (3/8 RM Stihl). Stihl recommends an angle of 10°, this is printed on their chain box.
Because the selfmade gauges aren´t that hype at the moment, I did not show even further development possibilities.
Because you´re bringing the topic up here, I show one possibility:


As always, advantages and disadvantages:
+ you can influence the raker angle
+ you can overcome the type 2 tool disadvantage of 'fixed' material thickness (by using a certain angle and knee point)
- the calculator gets more complicated
- you have to make a knee into the metal, which should be rather accurate (maybe difficult to make with normal tools), for industrial manufacturing it should be no problem

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

You know something about the spirit of this thread? Tell me more about this topic, could be interesting.

 

[hannes69]

he 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.

Very poor wording then... And there remains the contradiction in my opinion: You need more raker depth setting towards the end of chain´s life to maintain the cutting angle / attack angle, but on the other side it´s exactly the more raker depth setting that brings the cutter´s leading edge behind the hinge point in attack position.
I only ride on this point because a) PogoInTheWoods brought up this argument and b) Carlton makes false explanations to this topic and even show wrong pictures by purpose on the wrong place.
I´m not very convinced of the hinge point / see-saw topic... At least as long as nobody can´t explain it better to me than Carlton did in their manual.

 

[PogoInTheWoods]

I thought the see-saw illustration was very simple to understand. Even though the attack position is 'assumed' as the tooth angles upward after being shortened beyond the pivot point of the rivet itself, the cutter itself literally drops downward to create the upward cutting angle. My way of thinking would require a more severe raker adjustment at that stage of tooth length to allow the cutter any chance of grabbing a chip..., which is pretty much what Carlton states, or at least what I perceived their explanation to conclude.

I actually experienced that very situation yesterday while bucking a large storm blow down at my neighbor's house. 28" bar and chain setup with distinctly different length teeth on either side of the chain. Not dramatic, but distinct enough to be obvious. I started with a fresh grind and raker adjustment with the shorter teeth being right at that critical pivot point. I was cutting fine for the majority of the log when I either hit something in the wood or got into a real nasty rot spot that immediately dulled the chain. This resulted in the saw also beginning to cut on an angle after cutting perfectly straight up until then. My guess was that the shorter cutters were so close to that point of diminishing capability (relative to the pivot point) that the fragile tolerance at that juncture had simply been exceeded allowing the longer teeth to dominate.

Fast forward to the results of a new grind on both sides of the chain and corresponding raker adjustment. This grind clearly took the shorter teeth beyond the pivot point, but without additional compensation for the depth gauge height. The saw would not cut straight to save its ass. If I wouldn't have been under a time constraint, I would have taken another couple of passes on the short teeth rakers just to see what would happen. I'm pretty sure the cut would have straightened out somewhat. Perhaps not all the way, but I believe a detectable correction would have been realized. I don't believe that lengthening the rakers on the shorter cutters would have had any such effect, but rather quite the contrary.

As time and opportunity permit, I still intend to over adjust the raker height on this particular chain to observe the results. This is certainly as close as I'll conveniently (and quite coincidentally) get to an ideal chance for testing the theory in a practical application. Not that I'm recommending anything here, just that a couple more swipes of the rakers on the short side will undoubtedly provide one conclusion or another. Just need another handy 24" log or maybe a sacrificial round from my neighbor to give the particular method a try. I'll certainly post any useful results.

Another interesting observation while adjusting the rakers on this particular chain, which I believe is Oregon LG:

Projecting the angle of the Husky depth gauge tool used in the 'hard' position would line up almost perfectly with the far tie strap rivet as would be the case with a Type 2 tool. The 'soft' position would line up with the closer rivet in the same way. Hmmmm.

Still looking for a convenient and economical source of shim stock or tempered flat stock to experiment with a couple of Type 2's.

 

[Huskybill]

When the chain starts to cut more saw dust I eye ball the rakers and make two or three passes with the flat file. I don’t use a raker gauge.

 

[Westboastfaller]

∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆∆
.
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

Hmm, can you explain this in other words once again please? Where do these numbers come from? 100% over its depth / 1/16" chips?
Chips - reminds me of one approach: I never measured chips, could be interesting

Sure.
The only way I would know how to come up with how much more a new chain would dive over its initial raker depth CONTACT HEIGHT would be to start at the neutral position and calculate the depth at the same cutting angle.
(6.3° hardwood example)
I can get really close as in your data read out in your OP it shows your gauge is almost perfectly in que through what looks to be that neutral area of cutter wear.
I estimated it to be between 53- .054"
So the formula doubles basically.
.025 new chain = .053 measured at the centre of the see-saw (neutral )
An additional .028" dive over the raker setting of a new chain to equal to .053"
Its starting off basically at a1:1 ratio.
100%+ increase
.025" raker depth = .053 chip
I said 0.63 for softwood which is the number I'm certain Carlton had given years back. It seems to fall right in line.
.125" being 1/8.
So that's about 1/16" chip in a perfect world.

Stihl hard setting came in at .042 max and I made a few estimates from your OP
..Like about .013" short. roughly 25% raker depth los.
Your gauge doesn't have really any los to speak of in that same wear zone. Possible just 2- 3 % depth los.

If Carlton's .027- .047" max is based on hard setting then they are much tighter than stihl gauge on Stihl RM.

 

[Westboastfaller]

Using the third rivet top or centre with a straight edge (raker file) in the event of no raker gauge is an old trick BTW Hannes & Pogo^^^
A Faller about 5yrs younger taught me that one in 2007 when we partnered up.

 

[Philbert]

.025" raker depth = .053 chip
I said 0.63 for softwood which is the number I'm certain Carlton had given years back. It seems to fall right in line.
.125" being 1/8.
So that's about 1/16" chip in a perfect world.

How about the power of the saw? Does that factor into the optimal chip size?
A more powerful saw could pull larger chips, while a less powerful saw would optimize performance with thinner chips.

Philbert

 

[Huskybill]

Look down the bar/chain from the front, at the raker depth. I sharpen my chains with a file n guide. I make the same passes on each tooth. So there pretty much even. So two or three passes on each raker with a flat file is pretty much my rule of thumb.

I can pretty much gap ignition points at .020” too. Close enough so it will run.

 

[hannes69]

I thought the see-saw illustration was very simple to understand. Even though the attack position is 'assumed' as the tooth angles upward after being shortened beyond the pivot point of the rivet itself, the cutter itself literally drops downward to create the upward cutting angle. My way of thinking would require a more severe raker adjustment at that stage of tooth length to allow the cutter any chance of grabbing a chip..., which is pretty much what Carlton states, or at least what I perceived their explanation to conclude.

I think it´s easy to understand what they mean, but it´s poorly explained in my opinion.
The following pictures show my new designed cutter, until now only the parts concerning the raker depth gauge tool were accurate, now I measured more or less accurately the rest of the cutter and now can work with this info in my CAD program.
First the attack position for a 25 mil raker, the cutter is filed back to the hinge point.


The leading edge is now behind the hinge point and still barely touching the wood. Because of the initial raker depth setting of 25 mil we have a small attack angle of course.

Now the same cutter with a 6.3° cutting angle raker settting:


Now a higher attack angle, the leading edge is allowed to get farther behind the hinge point and so starts to point down.
The leading edge goes away from the wood - bad, but we have more attack - good. With a higher raker as shown above it´s vice versa. More or less.
Is this what Carlton wanted to say? If so, it was poorly explained for me. And still I don´t get why they ride on this aspect and don´t explain the huge advantage of a progressive gauge to better maintain the attack angle and the chain´s performance through its life.
And they speak of this effect here starting at about half cutter´s wearing. A little bit exaggerated I think. With normal cutting angles, the leading edge gets behind the hinge point for the last quarter of the cutter according to my measurements.
Interesting: the marking for the end ofl life point of my Stihl RM chain is positioned only at a very small distance behind the hinge point (~30 mil). In this area you have the hinge point problem and of course the rest material of the cutter gets into the region where the cutter could break.

As time and opportunity permit, I still intend to over adjust the raker height on this particular chain to observe the results.

Do that and please report back about your findings

Still looking for a convenient and economical source of shim stock or tempered flat stock to experiment with a couple of Type 2's.

Yeah, it´s time that you find some material, you keep my hopes up for the gauge tool presentation party

 

[hannes69]

The only way I would know how to come up with how much more a new chain would dive over its initial raker depth CONTACT HEIGHT would be to start at the neutral position and calculate the depth at the same cutting angle.
(6.3° hardwood example)

Thanks!
I invested some time in thinking over this whole topic, meditated over Carlton´s pictures ( ) and made some experiments in my CAD software with my virtual Stihl cutter.
Combining all this with your statement above I came to the following pictures and thoughts.

1.

I hope I did understand your statement right. We see teh hinge point, the axis through it, the neutral point, a new cutter, a raker depth setting of 25 mil and a 6.3° cutting angle for the filed back cutter.
When measuring the corresponding raker depth setting for the filed back cutter, I get a value of 57 mil.

2.


Now I try to simply do exactly that, what Carlton´s pictures show. In #2 the raker lifts up, until its tip has the same niveau above the bar like the cutter´s leading edge. The cutter and the raker both dive into the wood.
And, of course, the cutting angle in the previous picture showing up between raker and cutter´s tip now shows up exactly at the bottom of the cutter, between cutter and bar.
The cutter is in attack position and the raker penetrates the wood as well, which should be the case according to Carlton.

3.


Now the copy of Carlton´s #3. The cutter lifts off the bar until its parallel to the bar.
Now we see the size of the chip. When measuring this, I get a value of 54 mil. More or less the same like in pic 1, your approach

Now two pictures with the same scenario, but with the cutter filed back to the neutral position.




The chip size remains the same
If that´s all right, many circles will close for me.
This would mean the evidence for the 'constant cutting angle' concept.
The cutting angle when filing rakers stays constant. The attack angle / attack position of the raker remains constant. The chip size remains constant.
But all fo this is only true and a given if the pictures above and the corrersponding assumptions show up like that in reality.
I must confess: I personally have some difficulties in understanding setups containing moving elements and / or three dimensional aspects. I like two dimensional projections and still standing setups so you can work with lengths and angles. The movement makes things complicated. E.g. an angle becomes a torque...
I mean: Carlton made the pictures #1 - #3 like that. I´m not so sure if it is really like shown.
To completely understand the course of things, I would have to know:

- #2: Why rises the raker exactly up to the leading edge of the cutter? Could the raker hang below this point and #3 starts already (maybe NO penetration of the raker?)
- #3: Why rises the cutter up to the point until the cutter is parallel to the bar? Could it stop below the parallel point?
- after #3: where/why/when is the process finished, the chip has formed? By what is the chip length determined?

Would be a great help for me to understand that in more detail.
Though having some math skills and understanding of physical things, I have some weaknesses in imagination of kinematics I think.

I said 0.63 for softwood which is the number I'm certain Carlton had given years back. It seems to fall right in line.

Yes 0.063 for softwood according to Carlton, the 0.054 of the hardwood example here should fit

 

[hannes69]

Using the third rivet top or centre with a straight edge (raker file) in the event of no raker gauge is an old trick BTW Hannes & Pogo^^^
A Faller about 5yrs younger taught me that one in 2007 when we partnered up.

Different brains can come to the same solutions

 

[hannes69]

How about the power of the saw? Does that factor into the optimal chip size?

I think so
The optimal chip size is that one, that keeps the saw running at the max power rev point
Way too big chips and the saw bogs down, way too small chips you produce a powder cloud.
This problem partly compensates itself I think. A large powerful saw is probabyle used with a longer bar, a small weak saw with a shorter bar. Small saw, less power, less teeth cutting at thesame time / large saw, more power, more teeth cutting at the same time.
Of course the raker depth gauges kick in here. When cutting very hard wood with a very small saw and a too big bar, it´s a good idea to work with smaller cutting angles. And a big saw with a short abr cutting very soft wood can surely work with large cutting angles producing big chips.

 

[Westboastfaller]

Very poor wording then... And there remains the contradiction in my opinion: You need more raker depth setting towards the end of chain´s life to maintain the cutting angle / attack angle, but on the other side it´s exactly the more raker depth setting that brings the cutter´s leading edge behind the hinge point in attack position.
I only ride on this point because a) PogoInTheWoods brought up this argument and b) Carlton makes false explanations to this topic and even show wrong pictures by purpose on the wrong place.
.

Very true and poorly worded if they said more raker to maintain it beyond the rivet. No option can maintain it as its gone.
The gauge compensates more and more until it's 100% responsible for the depth. You are right as its a combination of a reduced tooth AND the increased raker depth creating a higher attack angle that makes it drop down further.
Their point is it can be overcome with more raker BUT the gauge only has the capability of delivering .047"
...And they promote the use of a gauge only.
They say you would need .063 (I believe they said)
They are saying.....The gauge can not balance this or can it deliver the depth needed as well a chain is incapable or cutting correctly with uneven teeth and it have diferent dynamics so its time for a new chain.

The dynamics are far different as to how it takes the chip. Don't think of it as knocking itself out of the cut but going forward and cutting itself on a down angle tapering the chip on its way to the open cerf. The resistance would be considerably reduced. If you're cutting in a max power range then my saws would be cutting at 60 kmph or 36mph.
Round filing chisel chain forces the chip down the gullet and forward until the chip breaks. Think of it as trying to snap something. The greator the angle, the more force needed.
Behind the rivet, the cutter is moving down with the chip as it moves forward and the chip thins to nothing. The cutter is also not as wide anymore. (Prehaps to compensate with a weaker neck?) With all the teeth the same, then a very low raker to start and a larger sprocket; this has been used for racing.

 

[Westboastfaller]

How about the power of the saw? Does that factor into the optimal chip size?
A more powerful saw could pull larger chips, while a less powerful saw would optimize performance with thinner chips.

Philbert

well if its bucking or felling, then a saw should glide through the cut opposed to chomping through the wood.
Even with .030" and a hook, you may get that affect in most species I've cut. Anything more on big power would seem to be on the outside end of optimal. If its not pulling your arms off then it may drop below you max torque speed.

For argument sakes, you could reduce the hook with a bit more raker. May be the best "chips size to resistance"

 

[Huskybill]

Open up the area where the grinder stopped when making the teeth. That step needs to be removed. The more room for the chip to curl the better. Then use the file n guide to sharpen the upper edge of the tooth.

 

[PogoInTheWoods]

Get the gullet. Still need the outside cutting edge of the tooth, tho I'm sure someone somewhere would argue otherwise. LOL

 

[Huskybill]

When we sharpen the inside of the tooth without the file guide below the upper cutter we sharpen the vertical side of the tooth too. Then with the file guide installed we now sharpen the total upper edge to the top of the vertical side too.

I noticed in the past just using the file guide alone we don’t always sharpen the top edge perfectly. It’s wavy sometimes on the top edge. With the file guide and the cutter fully hogged out now we file the upper edge perfect.

Once you try it you will see how much faster the chain cuts.

 

[Philbert]

When we sharpen the inside of the tooth without the file guide below the upper cutter we sharpen the vertical side of the tooth too. Then with the file guide installed we now sharpen the total upper edge to the top of the vertical side too.

Which file guide?

Philbert