View attachment 887956
Here is another STIHL description of these different angles. It does not explain why they are not different. I suppose that if you filed the top plate straight across they would be the same?
Philbert
Hi Philbert, not directly replying to you per sea, but for the sake of this thread, and those that read it in the future.
Most chain manufacturers now give 0 deg or 90deg, both the same thing of file placement for semi chisel. (0 deg across the top of the tooth, or 90deg to the bar.)
In this case, then yes, the side plate and top plate should be near equal.
Some manufacturers suggest a 10deg down angle, ie your hand holding the file handle is lower than the file tip that is passing the side plate, and this will give a different side plate, to top plate angle, as the file is lower when it passes the edge of the top plate, thus more hook on that edge, and less on the side plate.
Again, have a look at my earlier pictures of the chain, which show this.
Confused yet
Now as to why that is done, short answer, I have no idea, ive not really bothered to think too much about it.
Longer answer, I assume it has something to do with the chain cutters geometry, and how those angles work best with that tooth shape / geometry.
often with 10 deg down angle, its suggested to use 35 filing angle across the tooth, where as its more common to use 30 when your filing at 0 deg, ie no down angle across the chain.
(Yes, we often change that to better suit the timber were cutting, with less/ say 20-25, or more 35/40.)
Chains seem to evolve over time, and as mentioned different makes use different tooth shapes and thus require different file size and angles when filing.
It didnt seem like that long ago that 35 across the tooth and 10 deg down angle was a standard on most chains, even semi chisel).
We all agree that factory grind is an all round, it will cut ok out of the box, but we also all agree that we can then file and shape the cutter to what we are going to cut and make it cut better.
I can only imagine what its like cutting frozen wood, and what it does to a cutter, as we just dont get that type of weather here, and I would imagine those of you who cut frozen wood, would find it an interesting experience cutting some of the aussie hard woods when they are dead and dry.
Over the years I have tried and tested different tooth shapes to suit the varying timber I cut, and have settled on what I use now, due to ease of sharpening (fingers, hands and arms cramp after a day on the saw), and hand filing is not that good at the end of the day, so a guide, like the husky suits me, and the chain. I wouldnt bother using the guide if it gave a tooth shape that didnt work for me or the timber I was cutting.
If Im cutting different gum, i might hand file to suit the timber, but only in small amounts, as I am looking at the economy of time vs chain/ cutter life/ vs what is put in the trailer.
its simply not worth totally re shaping a cutter for one trailer load, if it was a few days of cutting, then yes, if it was an easy small adjustment, and not taking too much from the cutter.
Sometimes, its simply an adjustment of the depth gauge, other times its a change in file height.
Tho I prefer the depth gauges to be nearer the hard setting so I get a smoother less grabby cut, but as mentioned, that can change to suite what is being cut.
And again, the chain is also matched to the power head as well, so another factor to consider when comparing tooth shape etc.
cheers
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