If you need to reiterate the importance of shop safety to anyone operating the milling or CNC machine in your shop, this video should help.

D&J Precision Machine Shop in Cambridge, OH shared a harrowing experience they had with their milling machine earlier last week (May. 2, 2019.) A part not meant to spin as fast as it did quickly reached those speeds in what the machine shop is sharing as a teachable moment of sorts now that the ordeal is over.

Check out the video for yourself below.

If you didn’t already know, machine shops often machine heads and engine blocks after race engines blow head gaskets, a customer is rebuilding an engine, or the head or block needs a bit of reworking to clear a new part.

One of their employees inserted a fly cutter into the head of this milling machine and either told the machine to spin at 12,000 RPM or the machine itself spun up to those speeds. To give you an idea of what speed a fly cutter head is SUPPOSED to spin at, in my cursory search on Google I’ve seen anywhere between 500- 2,400 RPM with that upper end being quite the brag.

You can imagine that 12,000 RPM was a sure recipe for destruction. The path of destruction this small piece took was, to say the least, jaw-dropping. Not only did the counterbalance, the piece that broke off, go through the wall directly behind the machine, but it went through another wall, destroyed a chair, flew another 20-ish yards, nicked a concrete wall and finally went through another wall landing only God knows where.

The damage done to a real human is something I’d rather not think about.

It’s cliché to say but safety is always priority number one. Read all the shop manuals, wear all the safety equipment, and go through all the safety checks you need to go through before switching on some potentially dangerous equipment.

Have you experienced something similar in your line of work? Let me know what you went through in the comments below!