I have been using pcdmis on a Romer Arm for years but just got a job at a shop that has it on a CNC machine. Since I’ve only used it with a Romer Arm, I’ve never had to program move commands or alignment in relation to a machine. No one that I work with can tell me where or how to program alignment to the machine or the probe movement commands. Anything would help.
Well this is the NC forum. from what I understand, its just like programming a CMM. Create a program and it turns it into g-code for the cnc machine to understand. We almost got if for a few CNC mill turn centers but we didn't go through with it.
I'm using a CMS Ares CNC machine. I got the alignment figured out by putting a G-code in at the beginning of my program and the probe moves were actually really easy. Now for a more complex issue...every circle and cylinder diameter reads .003 to .006 too LARGE. I've checked them with pin gages over and over and the reports I get are always out. I have calibrated the probe a million times, I have calibrated it using different angles, etc. When I check a sphere, it is within .0002" every time. I have checked the machine head for errors too and it's consistent. What could be happening with my circles and cylinders? Also, certain distance dimensions have been out .003-.006 as well. When the diameters read large, they are always consistent. It isn't like one hole reads .003 and another reads .006. They will all be out the same amount.
First thing to keep in mind with PCDMIS NC is that the probe length on the machine controller matters.
PCDMIS uses the center of the probe tip when telling it to move, so that's what you should set your length to on the controller (and this should be as accurate as possible).
I've found that calibration will make sure that measuring a sphere reads the perfect diameter. But if your tool length is off, then you're not measuring the sphere at the actual apex or largest point. If that's the case, all the diameters you measure will be off.
Here's what I did for a particularly tricky disk probe:
1. Put the cal sphere in the machine, and give it a work offset
2. Then put a ring gage next to it and give it it's own work offset
3. Write a quick program that calibrates on the sphere, then checks the ring
4. If the ring checks off, then adjust the length of the probe on the controller
5. Re-run program
6. If it got better, then fine tune till it's perfect. If it got worse, reverse the direction and repeat.
This worked for me, hopefully it works for you. Also, you can set the work offset at the beginning of your program by using the code:
CNC/USEWORKOFFSET... Then you tell is G54, G55, etc.
