ASK THE EXPERT: Don’t crash

Share This Post

By Kip Hanson 

This is not a plug for CGTech, makers of VERICUT toolpath simulation software. Nor is it an attempt to promote CAMplete, Siemens NX, or other software systems (if any) able to read and simulate the actual G-code used by CNC machine tools to drive cutting tools through metal. 

It is, however, a huge endorsement of any technology that helps to shorten setup times, make the machining process more efficient, and reduce the risk of that heart-stopping, scramble for the emergency stop button event: a crash. 

At the risk of sounding like the old guy in the room, toolpath simulation software didn’t exist when I learned to program. Neither did personal computers, for that matter; the closest thing to “software” in those days was the paper tape we fed into the teletype machine. And even though CGTech released its first iteration of VERICUT soon after the company’s founding in 1988, my various employers since then were either A) too cheap to buy it or B) said the CAM simulation was good enough. 

As a result, program prove-out consisted of a nail-biting, one line at a time, ride the e-stop with one hand and the feedrate override with the other affair. And yes, more crashes than I care to admit. 

I suspect that times haven’t changed all that much for many shops. Crashes remain an unfortunate but accepted occurrence, as are setup times that take hours rather than the minutes they can and should be. 

Let’s address what my former employers told me when asked to invest in toolpath simulation software, starting with the “CAM simulation is good enough.” 

Has your CAM software’s postprocessor ever done something unexpected? Maybe it was a simple syntax error that only needed a few minutes to correct. On the other hand, it could have been a truly righteous collision, like that time I indexed a 3/4” Morse taper drill into a lathe chuck spinning at 5,000 RPM. Fortunately, the door was closed and, aside from my pride, no one was hurt, but the razzing continued for months. 

Neither of these or similarly unpleasant events occur with the systems outlined earlier. That’s because, unlike most CAM systems, they simulate the postprocessed G-code, and assuming you’ve modeled the machine, tooling, and workpiece(s) accurately, the only crash will be virtual, easily corrected with no one the wiser. 

As for the price tag, I get it. These systems aren’t cheap. And as just suggested, all that modeling takes time. But consider this: depending on the machine builder, a new spindle could cost more than the boss’s car. The resultant downtime could cost you your reputation with a key customer. 

In my fantasy machine shop, nothing goes to the floor unless it’s been through the simulation process. The programmer has had time to optimize the machining process and parameters, so tool life and part quality are better than they would otherwise be. Machine setup consists of loading the program and pushing cycle start. The first part is a good part, even on virgin jobs. 

Training and onboarding new employees is
easier because they can visualize the entire process. Everything is safer, downtime is reduced, and aside from birthday cakes in the breakroom, there are no surprises. 

Shouldn’t that be your fantasy, too? SMT

Kip Hanson

TECHNICAL EDITOR KIP HANSON has more than 40 years experience in the manufacturing industry. He is the author of Machining for Dummies and Fabricating for Dummies and has written over 1500 articles on a diverse range of metal manufacturing topics.

Share This Post

Recent Articles

Wordpress Social Share Plugin powered by Ultimatelysocial

Enjoy this post? Share with your network