Controlling and automating machine tooling and other equipment on the manufacturing floor with software isn’t a new concept. For those familiar with the process, it’s simply called “CAM”. For anyone new to the process, CAM means computer-aided manufacturing.
Here’s how it works
First, you design a part you want to machine using a CAD software tool such as SOLIDWORKS. Then you open your SOLIDWORKS 3D CAD design file in your CAM software tool. Now keep in mind that not all CAM software tools are the same. So I will use Mastercam for my example. Mastercam is the world’s most widely-used CAM software and for good reasons.
With its ability to support simple to complex designs, Mastercam will ensure that you’re ready for any machine milling and tooling job. Mastercam takes your SOLIDWORKS design model and turns it into a program. That program then drives a Computerized Numerical Control (CNC) machine, like this nice Haas Automation machine, and turns your design into a metal part.
Now for those of you new to CAM, I hope my brief explanation of how it works helped. To show you an everyday scenario using Mastercam, I have a tale to tell. And for those of you who use CAM, this tale may sound familiar.
This really happened...sort of
The day is just about over, all the fires are out, all the CNCs are humming, and the boss walks through the door.
“Hot job. Need it done ASAP,” he says.
“Is that the one I saw on your desk a week or so ago?” I ask.
“Yeah. Long story.”
I need tools. I take the paperwork and go find the SOLIDWORKS model on the server. It looks pretty intricate with a fair number of setups, but I don’t think I’ll need my Mastercam multi axis toolpaths. Looks like a three plus two approach will do. If I can, I use three plus two. This rotates the part into position and locks the rotating axis. The setup is nice and rigid that way.
Looking at the model a little closer I can see there are some fairly tight spots that will need a fairly small tool. After figuring out the rest of the tool list, I open up the stand alone Mastercam Tool Manager. I can build tool assemblies in there and, more importantly, set the stick out from the holder.
That will get me access and rigidity. I already have all the tools I need loaded in the Tool Manager, and I even went through the trouble of setting speeds and feeds based on material to make life easier when putting tool paths on the part.
I’m a programming machine
Now it’s time to program. I already had a template file for some fixturing that would work well for this part. I loaded that into my Mastercam. One of the features I really like about the latest version of Mastercam is that I can merge another part file by just dragging it onto the graphics screen while holding the Ctrl key down.
I can tell from just looking at the part that I’ll need five Tool and Construction planes, and three of them will be user defined. In older versions of Mastercam it would take a bit of clicking and maybe some geometry creating to get what I wanted. Now I can just click on the gnomon, drag it to my new origin and re-orient.
There’s a lot of pocketing and contouring and all sorts of fun stuff that all look tailor made for Dynamic Milling. One area is just asking for Opti-Rough. In the old days, I’d cut a ton of air at 0.100 step downs. Now I can put the whole flute length to work hogging out the excess and still stick close to the model surface with the step ups. The budget people love Opti-Rough: the tools last longer.
The jaw-dropping effect of Dynamic Milling
There was a lot of controversy in the shop when Dynamic Milling was introduced. A lot of the guys swore it would never work, that you could never run that fast of a feed rate. There was still resistance even when it was explained to them that you had to go faster in order to maintain the chip load.
All doubt was erased when we did an actual cut on a machine. Jaws dropped. They were impressed. Not only did the tool survive, but the machine was quieter and the spindle load meter was less.
I finished up the programming in a few hours. At least it seemed like a few hours. You know how it is when you get in the zone. I posted the NC code for the five axis machine.
The job was done and done on time so I sat back and lit a cigarette. At least I would have if I smoked, which I don’t, and the building allowed smoking, which it doesn’t. Anyway, I was feeling good.
Then the boss walked in.
“You put that job on the five axis?” he asked.
“It’s down. You’ll need to reprogram the whole thing again. I already let the office know that it’ll take another day to redo the program.”
A hero I am
I don’t say anything. He leaves. I replace the five axis machine with a three axis. All of my tool paths are organized by planes so I just need to create some Tool Path groups, move the ops into the right Tool Path group and rename the NC file.
Now I have a separate file for each setup. I put the programs up on the DNC system and let my boss and the shop know it’s done. I’m the hero for about an hour.
A week later I’m walking through the shop with the boss and I see hot job parts sitting on a pallet outside of QC. I look at the boss.
“Long story,” he says.
So it goes, right?
To learn more about Mastercam, visit our product page.
CNC machine image courtesy of Haas Automation, Inc.
About the Author
Mike Steelman started making chips in a machine shop in 1976. He moved into CNC machining in 1977. The coolest part he ever cut was one of the cargo bay doors for one of the Space Shuttles. In 1996 he had the opportunity to become a full-time CNC programmer. A year later he was offered the CNC Programming Manager position based on his qualifications as the only one of six programmers willing to take the job. In 2004 a chance to work at Prism Engineering appeared and he went for it. Mike is now the Mastercam AE manager for Fisher Unitech.