Essentially the size of the wheel (8" or 10") and the casing. The smaller casing is plastic, the larger metal. I have the 2006 if you want to have a look at it or try it out. The size of wheel does, of course, affect the degree of concavity of the ground surface.
There's more to it than just wheel size. The smaller (blue) model - 1206 - has a 120W input motor, rated only for 30 min per hour and a 200mm stone. The larger (green) model - 2006 - has a 250W input, continuously-rated motor and a 250mm stone.
The rotational speed of the 1206 is listed as 120 rpm vs the 2006 at 90 rpm.
The smaller diameter wheel will make a weaker hollow gring than the larger diameter wheel. Either one still requires finishing the edge to create a good cutting tool. Using the leather wheel on the 2006 rounds the edge of the bevel . If you strop your blade, it is best done on a flat surface.
At the risk of hijacking this thread is there anyone out there who has bought a Tormek and been disappointed with it?
Reading all the threads suggests that everyone who has one is convinced that it is the best method of sharpening that they have used. However there are also those non-users who are convinced that a Tormek will not achieve their required level of sharpness and that it is a grinding machine and not a sharpening system.
From the point of view of sharpening tools to use and not to admire under a microscope will a Tormek alone get my tools (chisels, plane blades, spokeshaves and planer knives) into a condition suitable for fine woodworking?
I've owned what is now model 2006 for several years. I too love it for what I use it for, which is for establishing correct bevels/angles on irons of used planes I purchase, correcting bevels/angles on irons that I've honed by hand and over time have messed up a bit, as well as establishing new bevel angles or significant back bevels or initial cambering of irons.
I also use it for the only sharpening for lathe tools as does my wife (the real turner of the family).
For planes, chisels and scraper irons, I always use stones after the Tormek, usually doing 2000, 4000 and finishing at 8000. Because the Tormek is a hollow grind, I usually add a couple degrees more than I would with a honing guide, which lessens the hollow at the edge. Honing takes but a few swipes per stone, more at the lower grits, less as I move up.
For Alf's sake, I won't mention the brand of the stones here, though [-(
Considerable discussion about the Tormek here recently. If it wasn't, IMO, seriously overpriced for what it does, I'd probably have one (despite the presence of water, Mike. :wink: ). I think a lot depends on what degree of sharpness you're looking for. I remember reading a post once where the writer couldn't understand how the blade on an under-used plane had got blunt from just sitting on the shelf. Then he realised it was just his standard of what consituted "sharp" had changed a good deal since he'd last put it away...