The renishaw probe on our Mazak mill had to be sent out for repair this week so I had to use the old starrett edge finder. The only problem is that on the Mazak the door has to be closed to have the spindle running which makes it hard to see when the edge finder pops. I have a German made 3d taster that I got from SPI a few years ago but I have never used it because I just don't trust it. I followed procedure and indicated it in and when I check an edge that I had just checked with the edge finder I get over .002" difference. When I use the edge finder to pick up both ends of a gauge block I get it to within a couple of tenths when I use the 3d taster its off by over .003". When I pick up a finished edge to do 2ed op work I need to be closer than .002". It makes me so mad to think I paid over $300 for this thing and all it ever does is take up room in my box. It *would* be the perfect tool for me to use right now but I just don't trust if for fine work even though the email I got from the German engineer from the company who makes it tells me it should be within a couple of tenths. Before I go through all the time and expense of sending it back to Germany for repair I need to know if I am expecting too much from this thing. Should I be able to do fine work (<plus or minus .001) with this tool?