G66 modal macro

[camtd]

Does anybody have the post setup to post out a G66 subprogram with position and or M98 subroutine? If so how is post builder setup to do this?

[aa8vs]

We used ICAM's post tool at the time post builder ['05] would not work for us. I would hope it is more advanced now, but principle should be the same.
We used first point as origin for modal macro
Next all motions with in macro were executed in incremental [G91 - mills] All main programs were in absolute [G90 mill].
At the end of each macro the post would close off macro, put controller back into absolute [G90] and restate current position in absolute to avoid machine loosing location especiall if a restart condition was involved.

[camster]

Post builder out-of-the-box is not "set up" to do this. You will need to add some custom commands to the post and some user defined events. It can be done and is not that difficult.
What version of NX are you using?
Have you ever done any customization to the post?

[camtd]

Hi John,

I have played with the post a little. But nothing like that.
I am guessing it would be in custom commands and add some sort of code.

I did do training with you a few years back but that was for some 4 axis work.

I am using Nx6 for a company that does aerospace the G code is a lot of 2 1/2 axis machining with positon moves.

[aa8vs]

We were using UG before it became NX and in '86 it was decided to go with ICAM post processing tool and we stayed with it until 2004. No post comes out of the box being able to do the G66 programming requirement but at the time using ICAM was not an issue but at the same time there was also Intercim and it was just as easy. At that time there was GPM available and for what our die plants were doing it did a decent job.

We had our plant in Bay City that had some exotic machining and about 100 feet of memory and the macro style programming and letting the post build the macros and then call them was a great approach for this application. Very short tape files and lots of machining.

At our plant in Strasuburg we had a similar situation with mulitple layers of machining. Built the first layer in a macro sub program move to a start location and call it several times and while your at it you can tapper the walls also. All fun stuff!!

When NX came into usage we did our evaluations and while it would take a lot of coding that time to get close to where we were at with ICAM it was decided that we would stay with ICAM but we recommended that the plants take a look at it because it had made some real advancements since the last time we had evaluated it.

We were programming production engine block and head lines and the placement of just everything becomes a cycle time issue. At the time [not sure about now] the NX post could not look ahead a few lines and gather information in order to build a safe start block. They said that would be coming maybe...

I changed jobs in the begining of 2005 and have not programmed a CNC since and you know, it was a fun time when I could.

[camtd]

Thats sounds amazing and fun. Did you have to do a lot of hand editing? Did you have a reference text or manual you used? Was there a NC verifier that you used to check the program?

[aa8vs]

Not a lot of hand editing at all in fact that was a company direction was to generate the tool path using UG and ICAM in order to create a file that you could put on the CNC machine. We used UG extensively to verify what the tool tip was doing with respect to the part in terms of travel. the tool verification if available was when tool approached the fixture and left to go back to toolchange position.

In order to verify this you had to build the model of machine in the system or... you could step through program on CNC itself. Which was most reliable, you would step through at reduced speed to assure general clearances and then once at full speed to assure the timing did not change. Rapid to finished surface stopped about 3 mm short then feed and cast surface 5mm then engage feed.

Biggest drawback we ran into at first was in a single feed stroke change speed and feed three times. With multistage tooling this was required based cross sectional areas of tool. At first it was hard to explain that to the salesfolks and more embarassing when you pointed out that APT could do that. But the later NX systems had finally gotten that one right.

We used the machine manual as a reference on what the various cycles did. In terms of drilling and boring we did that point to point rather than relying on the G8X cycles. It was found that each time the cycle line was read in it took 180 milli-seconds. Using G0 / G1 eliminated this but we could not use the G0 / G1 when rigid tapping.