This place makes for good reading on a sleepless night.
Best way I learned to sharpen was to draw lines on vice jaws using magic marker and trisquare for proper angle. I use both hands on file, and glance at marks to stay true.
In the field I put saw on tail gate and rest nose of bar against plastic bed liner.
Never tryed any gadget, but the roller guide sounds interesting.
Since noting how much the saw shop ground away, I stopped taking them there long ago and just learned.
Be interesting to read of "altered angles" here, though I am not saw smart enough to type about that.
