PM25MV DRO resolution questions

[javaduke]

OK, so there's something I'm clearly missing but I couldn't find any answer in the manual. I expect the reading on the DRO to be the actual travel distance on the respective axis - i.e. 1 inch of X axis table travel should read as 1.000 on the DRO. So I set the resolution to the 1.0uom. What I see is that 1 inch of travel results in the 2.000 on the DRO. So In order to get the actual distance displayed I had to set the resolution to 0.5uom. Doesn't really make a lot of sense to me. Am I missing something or is it how it is supposed to be?

Another question is, how can I reduce the number of positions after the decimal point? My DRO currently displays 6 digits after the decimal point, and I really don't need that kind of precision, a 1/10000 of an inch would be enough. Is there any setting for that? I studied the manual but couldn't find any answer.

 

[mmcmdl]

What I see is that 1 inch of travel results in the 2.000 on the DRO

It makes sense for x axis on a lathe . I'm sure somewhere in your manual will tell you how to change settings including your trailing 0s . Most are set for .0005 in shops , anything closer is utter nonsense . It isn't a jigbore .

 

[darkzero]

If you are seeing 6 digits after the decimal you have the micron setting wrong. If you have 1um scales, set to 1um, if 5um scales then set to 5um. This should give you 4 digits after the decimal.

To get the X axis to read actual travel set the radius/diameter mode in settings to radius. Some DROs also have a R/D button which will allow you to switch back & forth quickly without having to make the change in the settings.

Edit: Oops, just realized this is a mill, no matter, the settings are the same. Just make sure you have the DRO set for Mill in the settings.

 

[javaduke]

Hmmm, interesting, I just checked my settings, mine reads MILL 3 - which is what I expected, but I still can only get actual readings when I set resolution to 0.5um.
Don't think it has any radius/diameter setting - at least I couldn't find any mention of it in the manual.

 

[darkzero]

It should. All 3 DROs that I've had (different brands) all had it. Which DRO display do you have?

 

[javaduke]

I have the one that came with the machine. Here's the manual for it: http://www.precisionmatthews.com/wp-content/uploads/2017/01/PM-DRO-Manual-1-15-2018-Web.pdf

 

[Landmark]

Most inexpensive Chinese glass scales have a resolution of 0.0002 ( 2 tenths) which is 5um. To simplify a DRO counts ticks from the scale reader. Each tick is 0.0002" so setting the resolution to 5um lets the DRO know how far the axis moved for each tick.

 

[darkzero]

I have the one that came with the machine. Here's the manual for it: http://www.precisionmatthews.com/wp-content/uploads/2017/01/PM-DRO-Manual-1-15-2018-Web.pdf

Yeah I don't see the setting either. My guess is with your DRO, when set to mill mode it automatically sets it. You mentioned that you set resolution to 0.5um. did you actually set to 0.5um or 5um? 5um & 1um is most common. Assuming you have 5um scales, try setting to 5um instead of .5um.

 

[MSD0]

I would ask Matt. I’m surprised it wasn’t already set up (or included a quick setup guide at least).

 

[dcsleep]

I have a PM-25MV with the PM-installed DRO which was purchased last June. My DRO resolution is set to 5um and there's a separate setting ("INCH DOT") which can be set to either 4 or 5 significant digits.