Filing - guide positioning, direction of pressure, rakers first?

[Kenlip]

This might be ridiculously splitting hairs, but these questions are bugging my ‘OCD brain’ and I would love to get some answers.

For descriptive purposes, let’s assume the bar is clamped in a vice, with the top of the bar horizontal. For each cutting link, the tooth to be filed is on the left and raker is on the right.

Looking at the flat face of the bar, imagine a clock face, with the centre of the clock at the cutting edge of the top-plate of the tooth.

The top of the bar is running parallel to the 3 o’clock-9 o’clock plane. The top plate of the tooth slopes down, towards the 8 o’clock position.

When using a filing gauge like the Oregon style, does one have the plate of the guide resting on the top plate and on the raker, or does one have it resting flat on the top plate, sloping towards the 8 o’clock position?

If it is resting on the top-plate and the raker, because the raker is (presumably) lower than the edge of the top-plate, the guide will slope slightly towards the 4 o’clock position. This will produce a more pronounced hook. More on this later ***

If one has it sloping towards 4 o’clock it will file a deeper hook than if sloping towards the 8 o’clock position.

Is this difference in hook significant, and which is better?

Now, let’s look at direction of pressure. With the guide, I assume (perhaps, incorrectly) one wants to have the pressure somewhere between the 9 o’clock and 7 o’clock direction. One definitely doesn’t want it past the 9 o’clock, because that would lift the guide away from the tooth. What is the optimal direction of the pressure?

What about freehand filing, without a guide? In what direction should the pressure be applied?

*** With each filing of the teeth, the rakers become higher relative to the top plates. If one rests the guide on the rakers, the angle of the guide will differ depending on the height of the rakers relative to the top-plate. With this in mind, if one is going to rest the guide on the rakers, is it better to file the rakers first and then file the teeth? Of course, if one is resting the guide on the top-plate only, the raker heights don’t affect the angle of the guide.

 

[madmarksolomon]

 

[Mad Professor]

Wear gloves to save knucles. It will come to you.

 

[BJD85]

This might be ridiculously splitting hairs, but these questions are bugging my ‘OCD brain’ and I would love to get some answers.

For descriptive purposes, let’s assume the bar is clamped in a vice, with the top of the bar horizontal. For each cutting link, the tooth to be filed is on the left and raker is on the right.

Looking at the flat face of the bar, imagine a clock face, with the centre of the clock at the cutting edge of the top-plate of the tooth.

The top of the bar is running parallel to the 3 o’clock-9 o’clock plane. The top plate of the tooth slopes down, towards the 8 o’clock position.

When using a filing gauge like the Oregon style, does one have the plate of the guide resting on the top plate and on the raker, or does one have it resting flat on the top plate, sloping towards the 8 o’clock position?

If it is resting on the top-plate and the raker, because the raker is (presumably) lower than the edge of the top-plate, the guide will slope slightly towards the 4 o’clock position. This will produce a more pronounced hook. More on this later ***

If one has it sloping towards 4 o’clock it will file a deeper hook than if sloping towards the 8 o’clock position.

Is this difference in hook significant, and which is better?

Now, let’s look at direction of pressure. With the guide, I assume (perhaps, incorrectly) one wants to have the pressure somewhere between the 9 o’clock and 7 o’clock direction. One definitely doesn’t want it past the 9 o’clock, because that would lift the guide away from the tooth. What is the optimal direction of the pressure?

What about freehand filing, without a guide? In what direction should the pressure be applied?

*** With each filing of the teeth, the rakers become higher relative to the top plates. If one rests the guide on the rakers, the angle of the guide will differ depending on the height of the rakers relative to the top-plate. With this in mind, if one is going to rest the guide on the rakers, is it better to file the rakers first and then file the teeth? Of course, if one is resting the guide on the top-plate only, the raker heights don’t affect the angle of the guide.

This file guide was suggested to me not long ago. It works well and allows you to see the "proper" angle, depth ect. Then you can start freehanding with a baseline. If you buy it just make sure you get the correct one for your particular chain .325, 3/8 whatever you got. What I have learned is there is a factory recomendation of course but lots of people have much better results using their own tweeked process. Many different techniques out there cutting like butter and all slightly different. Dont forget to have fun and enjoy the process.

 

[Philbert]

When using a filing gauge like the Oregon style, does one have the plate of the guide resting on the top plate and on the raker, or does one have it resting flat on the top plate, sloping towards the 8 o’clock position?

Oregon and STIHL both say to rest part of the file guide on the top plate of the cutter and the other part on the depth gauge. But whatever you do, be consistent on each cutter to end up with consistent cutters.

The amount of 'hook' is basically fixed by using this guide. If you want more or less hook, you may need to free-hand file or use a different guide (like the one @BJD85 shows above, as one example).

Now, let’s look at direction of pressure. With the guide, I assume (perhaps, incorrectly) one wants to have the pressure somewhere between the 9 o’clock and 7 o’clock direction.

First, use a sharp file. They are consumables, like sandpaper, or Kleenex.
Second, only a gentle 'pressure' should be applied, pressing the file against the edges that you are trying to shape. Same with freehand filing, except that it is harder to hold the file in a consistent position on each tooth.

. . . is it better to file the rakers first and then file the teeth?

No.

The offset of the depth gauge is based on the height of the front edge of the cutter, which will not be known / set until you are done filing it (top plate is angled, not flat). File the cutter, the set the height of the depth gauge based on that.

Philbert

 

[Kenlip]

Oregon and STIHL both say to rest part of the file guide on the top plate of the cutter and the other part on the depth gauge. But whatever you do, be consistent on each cutter to end up with consistent cutters.

The offset of the depth gauge is based on the height of the front edge of the cutter, which will not be known / set until you are done filing it (top plate is angled, not flat). File the cutter, the set the height of the depth gauge based on that.

Philbert

It is interesting that the companies say to rest on the depth gauge. I wonder if this is based on the geometry or if it is just to keep things simple. I wonder if the different tooth geometries make all that much difference. Perhaps they don't, and as long as there is consistency, perfect geometry is not that important.

As you say, the depth gauge / top-plate relationship is variable. It seems a little strange to base a guide system on a variable.

I set up a 'desktop' simulation, with the coin being the file and the ruler being the gauge. This is not to scale! However, it does illustrate how the hook varies on whether one rests the guide on the top-plate (red) or the depth-guide (blue).

 

[46 Poulan]

Use guide to get your angle,good file,touch up chain before it gets really dull. I like to see and feel the good edge-cut wood and let the big chips fly---Happy saw and sawer--David Jonsered 621--I cannot find a better well made saw than this one. Powerful--oils like the Exxon Valdez--All magnesium--feels great in my hands classic. I blame Mr. Nicco and others here for getting me hooked on them--I have 5 of them maybe 6?? David

 

[46 Poulan]

Hey BJD85 welcome another Georgia boy--I am in Albany--I like the husky filekit also--wish I had caught that sale-some call me cheap-frugal. HA HA!!They say I love my bow saws also

 

[NSEric]

It is interesting that the companies say to rest on the depth gauge. I wonder if this is based on the geometry or if it is just to keep things simple. I wonder if the different tooth geometries make all that much difference. Perhaps they don't, and as long as there is consistency, perfect geometry is not that important.

As you say, the depth gauge / top-plate relationship is variable. It seems a little strange to base a guide system on a variable.

I set up a 'desktop' simulation, with the coin being the file and the ruler being the gauge. This is not to scale! However, it does illustrate how the hook varies on whether one rests the guide on the top-plate (red) or the depth-guide (blue).


View attachment 745846 View attachment 745847 View attachment 745848 View attachment 745849

This confirms that you should have the guide on the depth gauge, there's not enough hook the other way.
I have a husky sharpforce guide, it uses the cutters not the depth gauge to position itself and files the depth gauge at the same time. It's similar to the stihl 2in1 which I also have.

 

[Philbert]

I set up a 'desktop' simulation, with the coin being the file and the ruler being the gauge. This is not to scale! However, it does illustrate how the hook varies on whether one rests the guide on the top-plate (red) or the depth-guide (blue).

Yes, it makes a difference. But as one of my professors used to declare, 'it adds up to a mouse's fart in a windstorm'.

As a practical matter, you will not notice a difference outside of a controlled test fixture. That said, one of the advantages of doing your own sharpening is that you can experiment and find what works for you. Try different file sizes. Experiment with different angles (all of them). If you push the manufacturers hard enough they will admit that the specs they give are for 'general use'. Do what works for you, but try to do things intentionally and be consistent.

Philbert

 

[Huskybill]

I eye ball my rakers after the bar is squared and the chain gullet and top edge is sharpened, if the rakers are close to flush, cutting sawdust is one sign I make two or three passes on each raker. On the medium size saws and up, (50 to 75cc) I like the rakers between .025” to .035”, the 80 to 100 cc I can get away with the rakers at .035” to .040”. In hardwood. These saws have so much extra power I seen them pull a dull chain through the wood. Lol but I keep them razor sharp.

 

[Mad Professor]

If you want to use an Oregon style 3/8 guide/7/32, for .325 chain/3/16, put a match book cover between the guide and the file.

Works fine.

 

[Mad Professor]

How many here can sharpen a chain just with a file/handle?

I learned that way before I ever owned a guide. A guide makes things easier, or me lazy.

 

[Brent Adams]

46 poulan, do you pronounce that (All-banny) or (Al-bany)?
I'm from Elberton.
I usually freehand file(when I dont use the bench grinder). I file across and push up slightly to get the cutter edge sharp, then put some back pressure in and roll slightly to get the "gullet". Always check the depth gauge height with the Oregon gauge and do depth gauges last.

 

[Mad Professor]

46 poulan, do you pronounce that (All-banny) or (Al-bany)?
I'm from Elberton.
I usually freehand file(when I dont use the bench grinder). I file across and push up slightly to get the cutter edge sharp, then put some back pressure in and roll slightly to get the "gullet". Always check the depth gauge height with the Oregon gauge and do depth gauges last.

Just don't hit the sharp cutters when you set the depth gauges .

Another thing when filing, a few strokes less on the short cutters and more on the long ones.

Unless I'm milling I see no benefit filing off more metal than needed to make things sharp

 

[pioneerguy600]

Hand file only and file my chains to meet the use it will see, powerhead power, type of tree/wood and time of year for us here.Trees have more sap in them in the spring, wood is harder and often frozen in the late fall/winter months. Profile the cutter to suit the hardness of the wood, self feeding most important and set the depth gauges accordingly.

 

[Mad Professor]

Hand file only and file my chains to meet the use it will see, powerhead power, type of tree/wood and time of year for us here.Trees have more sap in them in the spring, wood is harder and often frozen in the late fall/winter months. Profile the cutter to suit the hardness of the wood, self feeding most important and set the depth gauges accordingly.

+1, I use a stump or a round in the woods for hand filing to hold bar, vise at home. Small chains/saws seem to like > cutter angles, rakers setting depending on powerhead/bar length/wood

 

[Philbert]

How many here can sharpen a chain just with a file/handle?

I CAN sharpen with an angle grinder, if I need to. A file guide or chain grinder makes me more accurate and consistent.

(But that might just be me.)

Philbert

 

[Kenlip]

I have a husky sharpforce guide, it uses the cutters not the depth gauge to position itself and files the depth gauge at the same time. It's similar to the stihl 2in1 which I also have.

Thanks, NSEric,
Of the Husky and the Stihl sharpeners, do you have a preference and, if so, why?

Cheers
Ken

 

[Kenlip]

Hand file only and file my chains to meet the use it will see, powerhead power, type of tree/wood and time of year for us here.Trees have more sap in them in the spring, wood is harder and often frozen in the late fall/winter months. Profile the cutter to suit the hardness of the wood, self feeding most important and set the depth gauges accordingly.

Thanks, Pioneerguy600
My saw is not great on the power front - Husky 141.
Yesterday, I read somewhere that, for Australian hardwoods, one should file at 25 degrees rather than 30 degrees. Almost all the cutting I am doing these days is cleaning up fallen, usually very dry, Ironbark and Stringybark. Does reducing the angle to 25 degrees make sense, and it it something I should do, bearing in mind the saw I have and the wood I am cutting?

Cheers
Ken