I have a Sino SDS6-3V 3-axis DRO and have discovered a problem relating to the direct-entry of axis coordinates. First a little about my setup. I'm using 10 um scales which have a resolution of 0.01mm or 0.000394". I typically work in inches. So here's what I've found. If I enter a coordinate that is not an exact inch multiple of 0.01mm, the DRO displays a value that is not the closest metric equivalent. In other words, when I enter say 0.255", the DRO decides to round down to 0.2547". The nearest multiple would have been 0.2551. Not a huge deal since we're only talking about a difference of 0.0003" versus 0.0001". Now if I then enter 0.2547", the DRO picks a value of 0.2539" which is two multiples lower. If I enter that number again (0.2539") I get 0.2527". For some reason, I can only get the DRO to accept the number I enter if it's an exact multiple of 0.000394". There is definitely a bug in the inch/metric rounding. Has anyone else experienced this?

The Sino was a replacement for an Acu-Rite 200 which died a while back. I'm using the same 10 um Acu-Rite scales. One thing I really miss is the way the Acu-Rite DRO handled the inch resolution display. Instead of showing say 0.2508 as the Sino unit does, the Acu-Rite would round to the nearest 0.0005" and display 0.2510. Having a resolution of 0.0005" is much easier for the mind to follow than a multiple of 0.000394". It would be great if Sino would give you the option of how scale resolution is rounded.

MotoDan