FG3 like FG2 looks like a very solid piece of hardware. I wonder how it would perform with tiny chains like the Oregon 90PX. In my experience, it's then hard to set up a guide like that to get those plates to encompass the rivets properly. As usual, I could be wrong, but I've never seen Stihl recommend 1/5. The jump was from 1/10 to 1/4, which is quite a big difference. Even the US version of the "Stihl Bar & Chain Manual" dated 2011-09 mentioned 1/10, although in the European versions 2010-10 there was already a change to 1/4. For 1/10 the cutting angle should be 37°, for 1/4 60°. In the old Oregon manuals they recommended 10%, while the cutting angle was supposed to be 60°. In others (also old) the recommendation was 20% and the cutting angle was also to be 60°. This did not make sense... McCulloch also used to have "their" value and it was 1/7 (14%). According to my maths the angle then should have been 44°. I will perhaps repeat here the values for some harvester chains that they measured in Sweden a few years ago. Measured as the cutting angle is usually drawn in the instructions, that is, at the edge of the top plate - in the middle of the kerf. Carlton: 44° Stihl 1: 43° Stihl 2: 36° Oregon: 46°
@@elpolaco7654 I will try and set it up on some 90PX sometime this week, it's going to be hard but I'll try. I think I keep getting the 1/5 from the Oregon manuals and keep mentioning it by mistake. Honestly I don't know how much of the file I have above, I just go by what looks right and check the side plate angle when I'm done. Probably not the right way of doing it but it works for me