Troy says the medium wheel takes on 0.001 inched per pass, so that's about 60 passes.
dm
I think there's a typo, either here or in that convo you had with him. The Medium stone takes off 1/10,000th of an inch, not 1/1,000th (
source). So it's more like 600 passes (assuming you can remove ~1.5mm of edge, total). That seems on par with the Swix Evo Pro you discuss later.
I was just on the RT web site medium grit is good for 1/10 of a thousand accuracy cut. I Call B..L S..T on that statement
I have done those type of tolerances in machining, and none of it was with a free hand power grinder. Requires very controlled conditions.
He's not claiming 1/10,000th inch accuracy; he's claiming 1/10,000th inch material removal per pass. Obviously it's more if you go slow and less if you go fast and it will never be exact. But I read that as stating approximately how much material is removed, not how precise the removal is.
I think if you go for the RT, at least stabilize the ski on chairs with towels, etc. Somehow. What a guy does with a tool he’s used for hundreds of hours is different than someone with no experience of that tool.
My ideal on-the-go solution is to wedge the tip or tail of the ski against two vertical planes that make a right angle (e.g. the inside corner of an outdoor stone wall). That's enough to stabilize the ski easily. If I don't have that, I'll push it against an outside wall straight on, with enough force to hold it in place while I run the RT along it. With practice it's pretty easy; but yes, if you screw up and relieve pressure you may muck up the edge angle at that one spot. On the rare occasion I do that, I live with it. It will fix itself in a tuning or two and as a hobbyist I won't notice the difference unless it's big and immediately underfoot.
Now, whether the RT is worth bringing on an airplane for a week, is a different question. To me, it comes down to conditions and group size. If I'm sharpening skis for a half dozen+ people, I'm bringing the RT. If I suspect I'll be skiing ice + trees for a week and repairing daily edge damage, I'm bringing the RT. Short of that, I'll skip it and bring my FK edger, 100mm file, and black diamondstone.