The only way to evaluate the worth of a grinder is to compare the amount of time it takes to hone a blade to a sharp edge.
1. With a fresh hollow grind on a Tormek, regardless of the width and thickness of the blade, it should take 2 or 3 (max) strokes on a Shapton 1000 to create a wire edge.
The advantage of the Tormek is that you can grind to the very edge of the bevel face, thus leaving the minimum amount of steel to remove.
2. Grinding on a half/high speed dry grinder, one needs to leave at least 2mm of edge on the bevel face (to avoid burning the thin steel). This is likely to take 5 or 6 strokes on a 1000 Shapton to raise a wire edge.
3. Now, taking the 1000 Shapton to a new flat primary bevel, how long will it take to create a wire edge? This is how it is traditionally done on Japanese blades. It is not an efficient method. I stopped doing this years ago.
4. It is more efficient to create a secondary bevel for #3 (aside - secondary bevels are OK for plane blades but not ideal for chisel blades). This means that you need to find a way of regrinding the primary bevel when the secondary becomes too large. Sandpaper? Diamond stones? Waterstones? In my experience they are all inefficient for this purpose. But don't take my word for it - do it and time yourself. That is the objective way.
Regards from Perth
Derek
