You do realize that the guide is only for use with
one size file - the size that is stamped on it, right? Using the other sizes on it will not give your chain the correct tooth profile. You have to get the matching guide for those size files.
With the right size file, and the proper technique, they do give very good results. The technique is a lot easier to learn and less prone to error than sharpening freehand. I use one of them regularly:
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I also use one of the roller guides from time to time. I like it a lot, since it gives a better view of the tooth as you are sharpening. Two reasons don't use it more often: 1) it's set up to give a 30˚ angle on the cutting tooth. Since I mostly run full chisel chain, I generally sharpen at 25˚. It is possible to sharpen at 25˚, but there all of the visual guidance the tool provides is for 30˚. (Not a HUGE difference, but it is noticeable if you are paying close attention.) and 2) It's small enough that I'm more likely to lose it in the woods (I suffer from the "set a tool down and it ceases to exist" syndrome).
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I prefer the depth gauge attached to the roller guide or one like shown below (when I'm using a sharpening tool like the first one shown). both result in a chain that is far less sensitive to having all the teeth exactly the same length.
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The other good hand sharpening tool I've tried is the Pferd Chain Sharp CS-X (which they also make for Stihl, which sells them as the Stihl 2-in-1 filing guide). It's not my favorite, though it does do a good job. A couple of friend swear by it. It's big advantage is ease of use/learning, and it's fast, since it files the depth gauge at the same time as the cutting teeth.
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