Please tell me more (or of anyone else has feedback). Is it user friendly, do the probes break if you look at them funny, do you need to do two revolutions to set an X or Y zero (not that I've ever fucked that up)? Did you buy the $349 version or the higher dollar one?
Not the guy you were replying to but...
I got the Tschorn for my mill after looking at what's out there. It is very user friendly and accurate IMO... it's pretty much like a manual version of a Renishaw probe - similar to the Haimer in operation. It has a large dial like a normal indicator, plus a small red/green gauge within the main display. You just touch the ball probe tip against your part and when the needle is on the white line between the red and green, you are right over the spindle centerline. Same thing for X/Y and Z. The larger dial reads out in traditional 5 tenths (well, technically 3.9 tenths since it's metric and each gradient is 0.01mm).
It has a rubber boot on the bottom to keep coolant and debris out, plus it has a breakaway connection between the mechanism and the probe tip, so if you do fat-finger a number, the tip should snap before you damage the gauge.
Not sure about the two revolutions to set X/Y zero. When touching off a square part, you move your X until the gauge reads zero and you're on centerline... set your X. Do the same for Y and Z. When touching a bore, I'd eyeball the center, then go left and right (well, +X and -X) to get my edges... go to the halfway point and that's zero. If I wanted to be super accurate, I could then pick up my Y+ and Y- from my calculated center point, but I found it was never more than a couple tenths (at most) different than my original X.
I went with the Tschorn because I read good things about service and support - people saying the designer/manufacturer told them to send in a crashed gauge and they fixed it free, whereas Haimer was hard to get a hold of and charged $$ to fix crashed gauges to the point that it was cheaper just to buy a new one. Also the Tschorn is slimmer and doesn't cause issues in your toolchanger if mounted next to a big facemill or something.
On a side note - I got a new CNC machine last month with a Renishaw OMP probing system, so I was thinking I should sell my Tschorn probes. If you're interested, let me know. I have two of them... they are the Slim Plus model which has the full dial gauge and is sealed against coolant/water. They are in pretty much in brand new condition in their original boxes. I run mostly production jobs so I rarely change my G54/G59 offsets. I think both were used maybe 2-3 times, if that.