Don't label all your cycles (2D contour)

Jake2465

Jake2465

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This was my first good crash. I wanted to flip my part over and do a chamfer on the back side. Instead of writing a whole new program just for a chamfer, I got the wise idea to use the same program that had about four ops in it and just tell the NC to run from that section of code that had the chamfer in it. Everything was fine until the mill was about to start the run and I saw the quill drop a lot lower than I was expecting and ended up landing the tool holder on the edge of the aluminum and rubbing about 1/8" of material off the edge before I could get the Estop to shut everything down. I wondered what in the world happened, and then I realized that I had named the op that used a 3/8" end mill (2D Contour) while also having the 1/4" chamfer mill that did the edge work (2D Contour)... They both happened to be about the same amount of lines of code too.
 
haha I've had a few run-in like that myself...but now imagine if that happened at 800 IPM or even at 100 IPM? :D I'm bad at labeling stuff especially after I make tweaks or duplicate toolpaths for minor changes, I guess because I'm always impatient to get cutting.
 
stioc said:
haha I've had a few run-in like that myself...but now imagine if that happened at 800 IPM or even at 100 IPM? :D I'm bad at labeling stuff especially after I make tweaks or duplicate toolpaths for minor changes, I guess because I'm always impatient to get cutting.
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That's where those VMC's can get scary. I once saw this business that owns a Mazak VTC200B run a good sized part. Nothing bad happened, but It was wild seeing that thing rapid from one place to another. It was one of those mills where the head did all the moving and the table was anchored to the main structure. I imagine that head had to weigh close to 1000lbs. Whenever it made a rapid move, those servos would make a screaming sound.
 
Yeah I can only imagine! I used to think high double digits were fast like 60 ipm etc compared to say my single digit ipms for the most part unless I'm drilling then I get into low double digits. Then I noticed people running 400+ ipms on Aluminum. That's just nuts. Although if you're a production shop and you've run the same part dozens of times at slower speeds I don't see why you couldn't just up the game on a well tested toolpath.
 
Jake2465 said:
That's where those VMC's can get scary. I once saw this business that owns a Mazak VTC200B run a good sized part. Nothing bad happened, but It was wild seeing that thing rapid from one place to another. It was one of those mills where the head did all the moving and the table was anchored to the main structure. I imagine that head had to weigh close to 1000lbs. Whenever it made a rapid move, those servos would make a screaming sound.
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Kind of reminds of me of this video I came across. They will get themselves in trouble really fast.

 
One of the better shops I worked in, and eventually ran, had a policy of editing the accel/decel parameters whenever we brought in a new machine to avoid such a strain on the servomotors. No need for them to immediately go to program speeds, especially when rapiding to position. That stuff looks impressive at the machine tool showrooms, but doesn't save meaningful time and adds wear and tear to the machine.

And those knuckleheads don't believe I single-stepping a new program? Depending on the programmer, I have run a few white-knucklers before, and even though it took time, avoided many a crash.
 
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