I don't get it. I've been tuning my own skis with great success for a few years. I like my tunes and feel competent at it. Friday night I was prepping my two sets of skis that I wanted for Saturday. One was already OK and hadn't been skied since last prepped. The second I wanted to hot wax and sharpen. I had just received a new file and though the skis didn't really need it, I wanted to try the file as it was a finer tpm. In the process of doing that, I saw on the back of the case for my swix file that I've been using, a picture of the file placed on the guide OPPOSITE of how I've been doing it.
In my drawings, the red and green are files and the black is the side edge guide. I've always oriented it the way the red one is. On the swix file plastic case, it showed it as the green one. When I tried it it cut on the bottom edge of the ski's edge and not the top edge. I marked here and there with a sharpie to make sure. Even went back to the red orientation where I hadn't sharpened yet and it covered the entire side edge, changed the orientation to green and only the bottom edge again. It's as if I went from a 3 degree side edge guide to a 2 degree side edge guide.
I decided to go with it and try it out on the hill. That never happened because the day didn't really go as planned and on top of that, I doubt I would have noticed anything as it was becoming slushy quick.
My question is why would changing the orientation change the angle? I clamped the file both ways so it wasn't loose.
Also, which do you think is really the 3 degree? If green is correct, have I been setting them to 4 without realizing it? That of course makes no sense to me but neither does the angle changing because I changed the orientation.