Whats causing this?

[Rob D]

You may find after the first sharpen that this does not repeat.

 

 

So difficult to get answers sometimes - we assume that all things like chains and chainsaws are made equally - but they must come out of the factory with slight differences.

[AHPP]

Is your guide (rail, ladder or whatever) bent maybe?

[Rough Hewn]

Various possibilities as aforementioned, other variables are wood grain, chain slipping on the bar and differing hardness/dry areas. I've had the same issues.

[Aicchalmers]

I get this too, I thought it could be to do with chain tension/oiling maybe? If I flip round the mill and use the pushing chain it seems to do away with it, which would suggest it could be? I've also got a couple teeth missing on one side from hitting nails but wouldn't have thought it would make a big difference like that.

[Woodworks]

I get this too, I thought it could be to do with chain tension/oiling maybe? If I flip round the mill and use the pushing chain it seems to do away with it, which would suggest it could be? I've also got a couple teeth missing on one side from hitting nails but wouldn't have thought it would make a big difference like that.

 

Might try flipping it around as a test

 

Thanks

[CCOS]

I've had some of it to using a Granberg ripping chain. I found that it was likely to happen when pushing hard and the chain isn't tightened fully so the chain can tilt and by that get wider.

Using a hand winch drastically improved my surface finish because the more even speed I can move the saw though the log.

[morten]

Sounds similar. Will try slower next time but not forcing and felt good but clearly something wasn't right.

 

Sharpening wise I am using a guide like in the picture but at 10 degrees not 30. Presume the hook angle is the same as a crosscutting chain?

 

Hook angle (side plate angle) should actually be a little lower (sharper) on a milling chain than on a cross-cut chain. One way to achieve this, is to use a file holder for a smaller diameter file. E.g. when using a 5.5 mm file to sharpen a 3/8" ripping chain, you can use a 4 mm file holder. Alternatively, you can put a shim under the file at each end to lift it up a little.

To achieve this, you probably need to use a STIHL file holder, which allows a bigger file to be fitted, which the Oregon file holder (with the spring clips does not)

 

By lifting up a 5.5 mm file by 0.5 mm, you change the hook angle (top-plate cutting angle) from the standard 60° to 45°. This makes the chain cut faster, and with less effort, but also makes the cutters more vulnerable.

 

One of the main reasons for using a more acute angle is that as you change the top plate angle from 30° to 10° (typical for milling), you actually increase the angle with respect to the wood. An analogy is when using a plane, you get a more acute angle by rotating the plane by about 30°, making it easier to plane.

 

Above information was obtained from the chainsaw milling "bible" Chainsaw Lumber Making by Will Maloff, originally published in 1982, but recently reprinted: https://www.amazon.co.uk/Chainsaw-Lumbermaking-Will-Malloff/dp/1626548447/

 

Excerpt:

The file guide, as it comes from the manufacturer, is set to file a hook angle of approximately 60°. To reduce the angle, it is necessary to shim the file in the guide at both ends, directly under both clamps. I usually use two or three strips of a matchbook cover to start, adding strips until the file cuts a 45° hook. It's a good idea to start with a conservative number of strips, to avoid removing too much metal.

 

(typo's from the first edition book corrected).

Edited January 15, 2017 by morten

[Woodworks]

Thanks Morten. Will give that a go