Chain Sharpening Questions: Rakers & Profile

[StihlRockin']

There are 2 angles when sharpening a Stihl or Oregon chain. The 30 degree top plate cutter angle, then the side angle. I've seen 2 different ways on the side angle. I've always had an up tilt angle, about 10 degrees or so, then this evening saw an older Stihl "How To" video and in it they recommended a straight/flat angle... no upward angle.

Am I right to do it my way, the upward 10 degree angle? Wouldn't doing it the way in the video make it cut slower? I'm also thinking it's the way a particular chain should be filed. I don't know because I've only used mainly Stihl and Oregon chains in the full chisel 3/8" .050 size.

The rakers. I haven't used a depth gauge for the raker height since the 90's. I've always done it visually, by how it feels and how it digs/cuts into the wood. A visual of chip size works too. When I file them down, the top is usually parallel to the guide bar. I may take 2 to 5 strokes depending on how much is needed to reduce the height. My question is the profile or the shape of the raker.... more or less the front of it. When I'm done the raker is flat-topped and I leave it at that.

Should I be doing something with the front of the raker, like round it off or something? I've never done anything to it except file the top. If I should be doing something to it, what is it and why? What does it do to the performance, etc?

I mainly use a 7/32 Stihl or Nicholson with no guide, just a round file and holder. The line on top of the cutter plate helps a lot too in keeping a proper angle.

Thanks,

StihlRockin'

 

[RedFir Down]

About your question 10 degrees or flat I could not tell a difference either way myself (6 or half dozen either way IMO)... but im sure there has to be a logical reason behind it. (I too would like to know)

Regarding the rakers I have always used either a 0.025 or 0.030 (depending on how much tooth was left) Oregon raker guide to take them down.
I always try to "shape" my rakers the same as factory, I have noticed the chain cuts much smoother maintaining the factory radius.

I discovered this thread a few weeks ago and I ordered a Digital Angle Finder to better my sharpening skills... I cant wait to experiment with it!
I cant get the pictures to load is the bad part... bummer!

http://www.arboristsite.com/communi...ly-progressive-depth-raker-generators.114624/
Bob (the OP of the thread) sent me this video to better explain the process.

 

[treesmith]

Same here, round them off a bit.
As far as as i know some chains are 10°, had one ages ago, Stihl are 90°/0° as are all the ones I use. Changing the filing angle can change the hook angles along the cutting edge, too acute or thin an edge and the faster it will blunt, too obtuse or fat and it won't cut. Angle the file right and you can even have both on the same tooth Think of each tooth as a chisel, you really want a consistent angle and hook along the cutting edge. According to the figures on the box the angle is relative to the top plate so bear in mind that chains can lean when sharpening.

Sent from my GT-I9210T

 

[Franny K]

Probably says in the saw manual that if using the kind of file guide or holder that rubs on the depth gauge and top of the tooth to go 90 degrees. Most manuals seem to suggest using this type of guide or gauge not sure which term is right they cost about $10 with the file and handle. The 10 degree then the way I read between the lines is for free hand or the type of guide that has a smooth rod in bushings. I just looked at a carlton and oregon box kind of amusing they have 90 and 10 but that is 80 degrees apart. 90 and 80 or ten and zero I would think if using the same convention to arrive at the angle.

 

[Warped5]

IIRC, chisel chain 'requires' the 10 degree angle, semi-chisel doesn't. But a couple of well-respected members here said to do them all at 90, because once that tip on the full chisel goes dull, angles make no difference. I've been doing mine that way since with no complaints, YMMV.

I am careful to keep the rakers at .025 - .030 and have a separate grinder set up just for those.

 

[mdavlee]

I file all round at 0. I've not tested the 10 to see if its faster but I know they'll be less meat in the corner.

 

[StihlRockin']

While sitting here trying to envision sharpening with either the flat or 90° AT the 10° angle, I'm starting to not see the difference or how it could be different since the more important angle(top 30°), as already suggested, is the more important one. I understand, or at least think I do, how the 10° makes that edge a bit more "thin", therefore more prone to getting duller quicker. Now to contradict myself... But then I'm thinking the thinner will cut faster. ?? I guess longevity over faster is more important to me. If I were to switch to the flat, I'd have to do it to a new chain.

Interesting. Thanks for the replies. I'll look into the info given. I got to get to sleep. I have to get up 2hrs 15min. from now! LOL!

StihlRockin'

 

[griff154]

I have mostly done 30deg top & 10deg down works for me. Makes want to try something differnt after reading these posts. But, on the otherhand if it ain't broke why fix it!

Sent from my SCH-I405 using Tapatalk 2

 

[mdavlee]

Most of my round stuff is semi chisel. I square grind all of the chisel.

 

[treesmith]

StihlRockin, just remember the angle is relative to the cutter top plate, if the chain leans as you file then the angle will be different, a 90°/0° could turn into a 10° upward, or, a 10 downward can turn into a 90° flat.
If the height of the file in relation to the top plate edge changes then the curve of the cutting edge (viewed from the side) changes too, the right file holder and file fixes this problem but the wrong horizontal filing angle changes it along the length of the edge. A thin edge will cut much faster but it won't have the strength and vice versa. An inaccurate 90° or 10° horizontal angle will also change the 30°/35° cutter angle even if you file to an angle guide. Where the file is angled too far down the far cutter edge will be thinner and longer as the file height is too low, the near edge will be thicker and shorter as the file height is too high, or variations of these. This is how I understand it for round files, never tried square but imagine the idea is the same.
Cheers,
Andy

Sent from my GT-I9210T

 

[Franny K]

I put a picture of two obsolete Oregon chain boxes. Note that even the same number and letter in the chain model get differing data over time.

I also noticed way at the bottom is the statement when using the guide go at 0 degrees which was called 90 on the other box.

 

[StihlRockin']

Rogue60 & treesmith.

Both excellent posts with good information... the kind of stuff that enlightens. It makes sense and am surprised after all these years I've never consciously noticed that angle in the picture.

Interesting info Franny K.

Thank you Gents!

StihlRockin'

 

[Thomas Venditto]

There are 2 angles when sharpening a Stihl or Oregon chain. The 30 degree top plate cutter angle, then the side angle. I've seen 2 different ways on the side angle. I've always had an up tilt angle, about 10 degrees or so, then this evening saw an older Stihl "How To" video and in it they recommended a straight/flat angle... no upward angle.

Am I right to do it my way, the upward 10 degree angle?
The rakers. Should I be doing something with the front of the raker...
I mainly use a 7/32 Stihl or Nicholson with no guide, just a round file and holder. The line on top of the cutter plate helps a lot too in keeping a proper angle.
StihlRockin'

I know this is REALLY late, but I'm in the SAME boat today and had to share.
Like you, I have both Oregon and Stihl chisel chains to sharpen. Both are .050 3/8"
Oregon recommends>7/32" file; 25deg top angle; 10deg drop
Stihl recommends> 13/64" file; 30deg top angle; 0deg drop
("Top Plate Angle" which I call "top Angle"; "File Guide Angle" which I call "Drop")

As for the rakers, I took this from the Stihl FG file guide manual. They recommend the flat top "a" as .5mm. They finish off the slope as per the witness mark on the chain. I think I read that having an abrupt shape raker may cause kickback(?).

 

[Thomas Venditto]

This is right from the Oregon web site.

 

[Thomas Venditto]

As for filing, it's one of those age old questions ... hand, jig or grind? or maybe Dremel?
I'm just a homeowner who grew up burning wood to supplement heating. I've been cutting my own wood for 20 years now.
I've been doing the Dremel thing and it's been fine for me. My dad's been using the same jig for 50 years. I have buddies who file by hand. Each person does his own thing and swears by it.

IMHO, no matter how "good" you think you are with a file or how much you "enjoy" filing, you'll NEVER be as accurate as a machine. Period.
Saw chain cutting depends on 3 things; 1.proper cutter ANGLE 2.same cutter LENGTH of every tooth 3.proper and same RAKER height, every tooth
As you can see, it's not enough to get the right angle on each tooth, but you also need to make each tooth the same length. A grinder or jig, although still not perfect, gets pretty close and makes it pretty easy.
I finally broke down and bought a Stihl FG file guide on EBay and like it.

Consider this. MOST of the "hand file" guys will tell you they bring their chains to a service once in a while to true them up. 'Nuff said.
TomJV

 

[cus_deluxe]

You may be technically right that youll never be as accurate and consistent hand filing when compared to grinding, but ive yet to see a ground chain (done by an "average " operator) cut as fast or feed as well as a properly done hand filed chain. Ultimately a grinder is a tool, and if the person operating the tool doesnt know what they are trying to accomplish then you can wreck a chain waaaayyyy faster than you can with a file. In other words: its not the grinder, its the grinder.

 

[Woos31]

So I've been reading through the thread here and it's very good and interesting to hear everyone's thoughts and what works for them. I'm only mentioning this as my 2 cents and nothing more meant to anyone, also that I would hate to see guys tossing chains in the corner because of it..............and this is length of cutter teeth. So I for a long time worried and worked over my chains to keep the length even until I had the light bulb moment. So as long as you keep your rakers at the proper depth say .25 for example, wouldn't a cutter tooth say 1/8th inch long still cut the same size chip as one say 3/8th long? If each tooth is filed/ground the same, the depth gauge or rakers is still what determines the bite the cutter takes. Now you've checked all rakers and they're all .25 on uneven length cutter teeth it would still cut the same as inertia from the chain traveling around the bar will hold the shorter tooth against the wood just the same to cut as the longer tooth wood. Again no rock throwing here just something I've noticed in my chain and wouldn't want anybody throwing chain and money out the window. Safe cuttin gents

 

[BenK]

There is a convenience and flexibility factor that applies to hand filing, which is something you can do in the field.

But the machines have the ability to be more precise.

I have had pretty decent luck with hand filing over the years (especially with the help of a file guide) and have never had an issue with the sharpness/functionality of my chains. But I also do not using my saw in an everyday work type of setting, nor am I trying to keep multiple saws operational on a day to day basis.

 

[heimannm]

Certainly not a universal truth, but at the WKY GTG a couple years ago they had a chain race, same saw and different guys brought their best sharpening efforts. The new chain out of the box won...

Mark

 

[Thomas Venditto]

You may be technically right that youll never be as accurate and consistent hand filing when compared to grinding, but ive yet to see a ground chain (done by an "average " operator) cut as fast or feed as well as a properly done hand filed chain. Ultimately a grinder is a tool, and if the person operating the tool doesnt know what they are trying to accomplish then you can wreck a chain waaaayyyy faster than you can with a file. In other words: its not the grinder, its the grinder.

Basically, I agree with you. I don't own a grinder for several reasons. I was referring to the difference between filing freehand vs a jig like my new FG3.
Regards,
TomJV

A decent grinder is expensive.
You gotta dress the wheel.
A diamod wheel is also exp.
They chew up chains.