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Running Collection of Useful Tips

This is a dual purpose topic, proposed to contain a collection of Useful Tips & Tricks some of us use on a daily basis; both to share with the community and to have a copy on the cloud when I forget!
First and foremost, the "0+0" rule.
For whatever reason, PC-DMIS loves to change nominals!
In order to fix this completely, any number that you'd like to not change needs to be set to an equation*
*I'm sure there are numbers that probably won't change very much...
I personally don't like to write out 0+0 every time I have the need for a 0.
I can't remember who told this to me (it was 100% from this forum, someone will probably own up to it) but I like to assign a variable instead.
ASSIGN/ZERO=ABS(0)
ASSIGN/ONE=ABS(1)

Now, whenever I need to have a 0 or 1, I just type zero or one.

This brings up a lot of points.
First and foremost, it is extremely important to be able to understand what you're programming. If you start making variables willy-nilly, and don't have a way to differentiate V1 from V187 without going through the variables and finding out what you had assigned them 2 years ago, you're gonna have a bad time.
However, if you set a variable called NOTCH_1_L_180, you know that that variable should be the nominal location of Notch 1 at 180° (part-dependant obviously).
Let's say you have two parts that are almost identical. You take the time to create a variable for every single aspect of every feature you're going to measure (it doesn't take as much time as it sounds).
Now all you have to do is File>Save as the new part number, change some variables and shell the program. Everythings all set up and ready to go, the new variables are initialized and the features reset once it's shelled.
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Personally I prefer to program using this method. Creating a variable for everything makes the program less likely to change, but makes it easier to change at the same time.
I personally do a lot of work with parts that come from a blank, say 15 different parts with the same notches at different locations, diameters, and depths.
I can program 1 part in a day or 6, and the other 14 the next day (exaggerated).
I'll always know what the variables mean, because I understand my own naming convention.
Mine, personally (as listed above) is the type of feature, the order of the feature (I go from datum to non datum, where applicable), what aspect of the feature (L for lcoation, D for Depth, R for Radius, etc) and the degree of rotation the feature is at (I work with round parts, if you haven't heard).

The variables themselves are nothing special, just the absolute value of whatever the blueprint says (I rarely get lucky with CAD models).
So instead of having to remember ever single number and dimension on the print, I just have to know that the Y-Axis is this variable, X is that, etc.
Makes it easier for me to program, anyhow.
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Hopefully I'll add more to this eventually
Parents
  • I'd really like to include something about alignments. I go for the Level-Rotate-Origin alignment process for our cylindrical parts; Leveling to the OD (cylinder), Rotating to a notch (plane or line, depending), and origining to the OD and a point.
    It would be cool to explain more of the process of why that's the way to go; I understand it simply locks down all 6 (DOF's? D'sOF? DOF?) degrees of freedom, and it lets me run my parts. However, I see a lot of times where there's not enough attention paid to the alignments.
    I can't imagine any good data being retrieved from a program with a bad alignment. Data can be retrieved, and the numbers could very well be in tolerance, but I couldn't trust a program that's not aligned properly. It's like trusting your CMM measures fine when it's out of calibration; sure, it could be fine, but do I need to go into detail as to why it could not?
    At any rate; if someone could help me explain alignments better, I'm sure we could all benefit.

Reply
  • I'd really like to include something about alignments. I go for the Level-Rotate-Origin alignment process for our cylindrical parts; Leveling to the OD (cylinder), Rotating to a notch (plane or line, depending), and origining to the OD and a point.
    It would be cool to explain more of the process of why that's the way to go; I understand it simply locks down all 6 (DOF's? D'sOF? DOF?) degrees of freedom, and it lets me run my parts. However, I see a lot of times where there's not enough attention paid to the alignments.
    I can't imagine any good data being retrieved from a program with a bad alignment. Data can be retrieved, and the numbers could very well be in tolerance, but I couldn't trust a program that's not aligned properly. It's like trusting your CMM measures fine when it's out of calibration; sure, it could be fine, but do I need to go into detail as to why it could not?
    At any rate; if someone could help me explain alignments better, I'm sure we could all benefit.

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