How Did You Get Into CMM Programming?

Serendipitous. OGP machines a million years ago, the engineer who was trying to write programs was not having success, so I got drafted.

Our CMM programmer was a no show after getting his Christmas bonus. I asked my boss who was running the CMM at the time what it was, then shortly after when he would teach me to run it. His response was "right now". That was almost 30 years ago now, it's been all down hill from there.

Like Cris_C , in 1995, I was learning to get a engineering degree ( night and weekends) while I worked in a lab, and I had to study the capability of a measuring column, with a set of gauge blocks, a thermometer in a shop without air conditioner (it was in july !). I couldn't understand what I was measuring... I then understood that the results were changed in a function of the coef. of thermal expansion of the scale, glass made. I found it was exiting !
Then, with a lever comparator and a rotary (yeeeees ! my first one ), I wrote some excel sheets to get flatness, circularity, concentricty on circular parts, and tell to my boss that a cmm could give more results.
We get an old manual Johansson (Cordimet 1200 with Flexylearn), which was to small for our parts, but usefull enough to prove that a cmm was the right solution. The boss bought a Chameleon, with PC-DMIS 2.06xxxx, with a SP600, a rotary (), and it was the start !

I hoped Hexagon would train for longer not just 1 week per level. What can you learn in a week? And when you have no mentors just yourself what can one week do? Level 2 was most useful but the instructor had only a short time to teach iterative & best fit alignments which was woefully not enough. 2 examples for iterative & one for best fit? I still have trouble getting around best fit alignment; iterative is a little better because I did some programs with that alignment. There was nothing about equate alignment I only got to know it via scrolling down on this forum hahaha.

I hoped Hexagon would train for longer not just 1 week per level. What can you learn in a week? And when you have no mentors just yourself what can one week do? Level 2 was most useful but the instructor had only a short time to teach iterative & best fit alignments which was woefully not enough. 2 examples for iterative & one for best fit? I still have trouble getting around best fit alignment; iterative is a little better because I did some programs with that alignment. There was nothing about equate alignment I only got to know it via scrolling down on this forum hahaha.

Welcome to the club! Most of us have had the 1 week training and thrown into the fire. The foundation was established from that week training and bridged out through the forums and trial and error. Many times my head pounded on the desk, that little voice inside said I can't do it, heavy loads of frustration, and nobody except this atmosphere to turn to. It's how you response to those instances that show your true character and will either make or break you as a programmer.

Welcome to the club! Most of us have had the 1 week training and thrown into the fire. The foundation was established from that week training and bridged out through the forums and trial and error. Many times my head pounded on the desk, that little voice inside said I can't do it, heavy loads of frustration, and nobody except this atmosphere to turn to. It's how you response to those instances that show your true character and will either make or break you as a programmer.

I think what would have helped me a lot is a good book. I know that the help file is quite extensive and that there is a PDF manual, but there aren't a lot of examples there of how to structure a measuring routine. A book full of example parts, drawings, code examples, and a detailed explanation about what to do when would have been a huge help when I was getting started. Luckily, I muddled through, but I could have avoided a lot of simple mistakes along the way.

Hexagon offers a whole lot of training videos now that weren't available when I was getting started. I haven't watched any of it myself, but I have a coworker that is getting started with PCDmis and says that he has found it very helpful. There is also some stuff on YouTube. So, I guess the number of resources is getting better.

First QC job I had, everyone was expected to learn how to use the CMM eventually. Shop had grown very quickly and about 15 to 20 new QC inspector trainees were hired in about 2 years time. Took about 5 years for it to be my turn.

First CMM I worked with didn't even have a computer. Really early model Cordax. Had a DRO with hard probes. You had to mechanically align the part on the table and literally drop the hard tapered probe into the holes.

After a couple years we upgraded to a Cordax CMM with a HP computer and a tape drive. Had a massive 5 inch screen and a built in thermal printer. Still mainly used hard probes but there was also a touch probe. You had to tell the CMM which direction to apply probe compensation.

We also had a DEA gantry CMM with a 5 foot by 9 foot granite table. It was a manual machine that ran off a computer the size of two lockers. Didn't have a display. Everything was printed on a teletype printer. Printer was parked under the Gantry Cross beams that were only 5 1/2 feet above the floor. Lots of cracked heads. Probe was qualified using a cube shape artifact. If you wanted to change the orientation of the probe you had to disassemble and reassemble it from the mast. Orientation was limited to +X, -X, +Y, -Y and Z.

Finally got our first DCC CMM's for the shop floor a few years later. 1808 Cordax's with real PC's. We measured first parts, last parts and occasional parts during the run. Had Renishaw PH9 probe heads. Doing a probe qualification could be a real pain. You had to move the probe close to the calibration sphere, take a reading and then move the probe to another point that hopefully created the correct vector. If you screwed that up the probe would move in an unexpected direction. You couldn't cancel the movement; you would have to shutdown the CMM and start over. One of the guys eventually figured out how to calculate vectors and enter them into the calibration code. He created a checklist/ cheat sheet for us to use.

We also had a DEA gantry CMM with a 5 foot by 9 foot granite table. It was a manual machine that ran off a computer the size of two lockers. Didn't have a display. Everything was printed on a teletype printer. Printer was parked under the Gantry Cross beams that were only 5 1/2 feet above the floor. Lots of ******* heads. Probe was qualified using a cube shape artifact. If you wanted to change the orientation of the probe you had to disassemble and reassemble it from the mast. Orientation was limited to +X, -X, +Y, -Y and Z.

It hadn't occurred to me that there was a time when manual gantry CMMs were used. What a lot of work that must have been to use!

Like Then, with a lever comparator and a rotary (yeeeees ! my first one )

​What is a rotary? I'm not familiar with that term.

Like We get an old manual Johansson (Cordimet 1200 with Flexylearn), which was to small for our parts, but usefull enough to prove that a cmm was the right solution. The boss bought a Chameleon, with PC-DMIS 2.06xxxx, with a SP600, a rotary (), and it was the start !

I haven't heard of Johansson brand CMMs. Is that the same company that made gage blocks a thing?

I like how your boss went from an old manual machine right to a machine with an SP600. What a step up! You must have really convinced them that a CMM was a good investment.

It was a joy.... It was a mid to late 70's model cmm. Used paper tape if you wanted to write a program in Fortran. Very few programs were written. Had a couple of hand boxes where you spun dials to tell it to measure the various feature types and do alignments. Measurement results were printed on the teletype as soon as you finished the feature. You were hanging from some handles to move the machine in X and Y. Luckily there was a roller you could spin to move the machine rapidly in Y. Had this nasty habit of dying on the last feature you wanted to measure. Constantly banging your head against the gantry. It was originally bought to measure hole locations on a tank mounted TOW missile launcher that took up most of the volume. It was however much faster than trying to layout that launcher by hand and it was a lot of work. It was pretty much state of the art at the time. Guys who were originally trained on it thought it was by far the better system while the Cordax guys thought the opposite.