What's The Best Way to File/Grind Rakers?

[Ralphie Boy]

Ok, so let me rephrase the original question. As I understand it, as you sharpen a chain you are changing the shape of the cutter by reducing their size. Again, as I understand it, in order to get the correct depth setting on the rakers/depth gages one needs what some one on this forum referred to as "progressive" guide for the rakers/depth gages.

First, do I have any of this correct? Second if I do, what type of gage do I use for manually sharpening and where do I find it??

 

[smokinj]

You are right. Its not that big of a deal with cross cutting but milling becomes more of an issue. No kind of gauge that I am aware of. I use a file and count strokes.

 

[StihlHead]

The depth progression is set by the top of the cutter, so all you need is a depth gauge and a small flat file. I use one of these:

 

[bogydave]

My file kit came with one of these gage & flat file for the rakers.

(broken link removed to http://www.ebay.com/itm/DEPTH-GAUGE-FLAT-FILE-FOR-CHAINSAW-SAW-CHAIN-RAKERS-/390350482943)

 

[Thistle]

You are right. Its not that big of a deal with cross cutting but milling becomes more of an issue. No kind of gauge that I am aware of. I use a file and count strokes.

Crosscutting - every 2-3 sharpenings I give them 2-3 light strokes with triangular file used for sharpening hand saws.Most are about 1/2" wide.Milling tends to be sooner.A bit 'heavier' for milling softer woods,a lighter touch with the file for White Oak,Honey Locust etc.Imagine my surprise about a month ago when ripping some HL with the same chain used on White Pine in late February... It went alright,especially with the 2100,but liked to rattle my fillings pretty good....

 

[Ralphie Boy]

so all you need is a depth gauge and a small flat file.

And there's the part that had me confused. In the same post I mentioned it was stated that the raker gage that came with the Stihl file kit was not "progressive" and pretty much useless.

 

[KaptJaq]

An old post showing the husqvarna depth gauge... One side leans on top of the cutter so as the cutter gets lower the gauge exposes more of the raker to the file. Click "view attachment" to see the picture attachment...

Below is a picture of the depth gauge on the bar to file the rakers. Choose the slot that is appropriate for the type wood you will be cutting, "hard" or "soft". The "soft" slot makes a deeper cut. Make sure the depth guide tooth is fully in the narrow part of the gauge as pictured below. Once the gauge is in place use the flat file that is included in the kit to file down the depth guide tooth to be flush with the top of the gauge. Don't file too hard or you will cut away at the gauge.

KaptJaq

View attachment 95719
(Click image for larger view)

 

[Bigg_Redd]

And there's the part that had me confused. In the same post I mentioned it was stated that the raker gage that came with the Stihl file kit was not "progressive" and pretty much useless.

I have no idea what "progressive" means in this context, but, I do know that all the gauge does is keep the raker/tooth ratio constant.

I have/had one but it turns out they only work on full comp chains so I never used it.

 

[MasterMech]

The issue is not so much maintaining the required edge to raker difference, which the Stihl and Oregon tool will do, but maintaining the angle at which the cutter edge touches the wood. As the edge of the cutter recedes from the back of the raker, the "angle of attack" decreases. If it decreases too much then the chain will cut slow. Hasn't been a problem for me so far. After awhile you can adjust the rakers by "feel" in the cut.

 

[StihlHead]

I have no idea what "progressive" means in this context, but, I do know that all the gauge does is keep the raker/tooth ratio constant.

I have/had one but it turns out they only work on full comp chains so I never used it.

Hmmm, you have a point there about rakers on skip loops. The depth gauge style that I posted depends on full comp teeth to set the raker height.

As for progressive, what I think that what 'they' are referring to is that as the chain teeth are filed down, the depth of the rakers needs to be increased to maintain the same angle of the cutter teeth when they are in the cut. When a chain is new they usually recommend a 0.025 raker depth, but as the tooth is filed back and down, the depth needs to be increased to more like 0.030 in order for the teeth to cut at the same angle as when the chain was new. By the end of its life, the depth may need to be as much as .035 on a 3/8 std. full chisel loop in order to maintain the 'as-new' performance level. To maintain the "progressive" lowering of the raker depth over time, you can use a Carlton File-O-Plate tool.

Clear as mud? There is a downside to progressive lowering of the rakers though. The force on the cutter teeth is increases as the raker depth is increased. That also increases the kickback from the chain. For that reason the factory recommendations (both saw and chain manufacturers) usually recommend .025 for the life of the chain. Even then the kickback increases at the end of a loop's life and that is one reason that safety loop rakers have weird designs and they become virtually useless toward the end life. I keep my old loops for cutting potentially naily wood, or for cutting stumps in crud and dirt.

And there's the part that had me confused. In the same post I mentioned it was stated that the raker gage that came with the Stihl file kit was not "progressive" and pretty much useless.

As for being useless, they work fine on newer chains, and are "recommended" for the life of the chain (for reasons stated above). You can get a File-O-Plate, or you can get a set of depth gauges, and use a 0.025 to start, and then 0.030 and 0.035 as they wear out. I use a similar method to file my Stihl loops, because the cutters taper so deeply. On 3/8 chain I start with a 7/32 file then change over to a 13/64 file when they 1/3 shot, and then use a 3/16 file toward the end of life. Stihl wants you to use 13/64ths for the life of the chain, but as chains wear down that size file tends to file into the links, and/or reduces the sharpening angle at the top of the cutters.

 

[mywaynow]

I just make it a point to hit a stone every so often and that keeps the rakers in check.

 

[ScotO]

my method is a bit more "redneck". I don't use a guage, matter of fact I use a four inch grinder with a flap disc on it. I don't use any pressure when hitting the rakers, I just lightly 'bump' each one of them. And with the grinder, you have to be careful you don't bump the cutters. I put the bar (or the whole saw) in the vise when performing my sharpening duties. Now, if you are milling, this wouldn't be a very precise way to do the rakers. I do this on my felling and bucking chains. If you are new to sharpening chains, you want to learn to file them. Take too much off of one or two rakers, and you'll know it....trust me from experience!!

 

[StihlHead]

If you do chainsaw milling, you may actually want a lower raker depths, to more like 0.020. Some guys file down every other tooth top plate on chains to lower the resistance and amount of slice that the cutters make to reduce the stress on the saw when milling. The stuff I posted above is for cross cutting and noodling. Though with noodling alone you can go deeper. Its about the grain and the way you cut across it, as well as the chain you use. From easiest to hardest cutting with a chainsaw, its noodle cuts, then cross/bucking cuts, and finally ripping/milling cuts.

Oh, and the File-O-Plate does not work with skip chain either.