DRO on mill - which way is which.

[gearedloco]

Well, I finally got the DRO mounted on my circa '83 Jet mill. Everything's hooked up, and when you turn the wheels the numbers change. I've started to do the configuration, and right off the bat I've run into a philosophical issue.

Which way should the numbers change (count up or count down) when an axis moves in a particular direction? Is there a "standard" or "conventional" arrangement for this? I can come up with a whole bunch of different arrangements that sort of make sense, but nothing seems quite right.

I seem to remember reading something about this, but I have no clue where or when I read it. As far as I can see, the instruction and installation manuals don't address the issue. Maybe it doesn't even matter, but I'd sure like to avoid future confusion.

I had similar issues with programming microprocessor-controlled microscope stages in the far past, but there was an easy way out. I'd just ask the Principal Experimenter how he wanted it to work, and that was that! IIRC, no two experimenters used the same conventions.

What say ye?

-bill

[macona]

As the table moves towards your right and the table moves away from you the numbers count down to zero. As the table drops away from the quill the Z increases.

[MuellerNick]

It is always distance tool::work. The bigger the distance, the more positive the number.
Z is always the rotating axis. Z-axis horizontal on a horizontal mill, along the spindle. Z vertical along the spindel on a vertical mill. Z horizontal along the spindle on a lathe (except vertical lathes, here Z is vertical).


Nick

[SGW]

It's your shop -- do it whichever way you find most intuitive.

[MuellerNick]

do it whichever way you find most intuitive.

Right now, I decided to name the axes after girlfriends.
The axis going the most to the negative will be called "Andrea".


Nick

[Dr Stan]

Rene Decartes was the mathematician/philosopher who discovered the Cartesian Coordinate system which is simply three number lines that intersect at their zeros and at right angles to each other. The standards he established are easy to conceptualize if you imagine yourself looking down from above the mill.

The Z axis is always the center line of the spindle, so in the case of a mill the spindle going down it is negative, and up it is positive.

Going to the right of Z one is traveling on the positive side of X. Conversely left is negative.

Going in front of Z (toward the column) you are traveling on the positive leg of the Y axis.

Just keep in mind the negative and positive are used as directions just like north, south, east & west. You can Google "Cartesian Coordinate system" and find lots of info.

[danlb]

For mine, I set it to mimic the dials on the handwheels. If I use handwheel instead of the DRO it's still the same.


Dr Stan is decribing a x-y layout where 0,0 is on the lower left corner. If you have a drawing that chose to put 0,0 somewhere else you can adjust the DRO to match.

Dan