OMG, I gave myself such a headache. Over thinking or too much data or something. Turns out that is not the only chain that is supposed to get that 10 degree down, as if holding file handle 10 degrees down. That is per Oregon, but they have a caveat that says to hold level if using an Oregon file holder. Something is wrong there because they give part numbers for holders, files, depth guage, and even grinder and then show drawing of file held down or setting angle on grinder (510 or 511). Looking in manual for 511 they actually talk of setting that and there is a scale for setting the chain holder off of vertical. But manual does not mention for model 510. Too much money for me to spend as well. I could buy a lot of chain.
If that is not enough of a gotcha, three different angles to set for sharpening, they only offer certain size grinders, no 4.5MM. So do you dress the next larger wheel to the radius of a 4.5MM?
And if that is not confusing enough, I see rave reviews of those el-cheapo grinders that have only one angle setting.
"Now, where is that tylenol? My back is hurting too."