My close call with a CNC sim made me question it.

The program looked fine on screen (seriously, no errors shown) but would have crashed the tool. I've started double-checking by hand now, what about you?

4 comments

4 Comments

betty_jackson1mo ago

Yeah that "no errors shown" thing is the scary part. The sim only checks the code itself, not your actual material or if your workholding is weird. I caught a similar issue once where the sim was fine but the tool would have plowed right into a clamp. Hand checking is smart, but don't ditch the sim completely. It's still good for spotting the really obvious stuff before you waste time.

sandra_flores851mo ago

Our shop ran over three thousand programs through that same sim last year. Only two bad ones got through, and both were weird fixture setups. Honestly if your post process and work holding are solid, the sim catches 99% of problems. This feels like making a big deal out of a rare event.

the_gavin1mo ago

In our shop, sims pass programs that would hit clamps about once a month. It's a known gap, but not a crisis. We still use the sim for quick checks before any hand work. The real risk is skipping the manual step, not trusting the sim too much.

jason_henderson1mo ago

Man, my buddy Mike had that happen at his shop last year. Their sim showed a clean run on this aluminum bracket job, no warnings at all. He loaded the material, hit cycle start, and walked away. Came back to the sound of the end mill screaming because it tried to cut where the vice jaw actually was, not where the sim said it would be. Totally trashed the part and chipped the tool. He said the sim just didn't account for how their vise was really set up that day.