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[hooligan machinist]

These Haas machines in question failed on their own with no help from me.

You had your fingers crossed when you typed that, i just know you did!

[sno_duc]

The most spectacluar machine failure I've ever seen  was a LeBlonde 12x12 lathe.
I got tasked with doing a post mortem, the machine was totaled ( bent the ways, headstock partial ripped off the ways )
The coupling between the spindle and the speed encoder failed. When the computer saw the speed feedback slowing it tried to maintain spindle speed. There was a 18" 3 jaw chuck with large aluminium pie jaws mounted on the spindle. At some point 10,000 rpm?? one the jaws came off (barely missing the machinist), this cause a huge imbalance at very high rpm, and she tore herself apart.

[hooligan machinist]

The most spectacluar machine failure I've ever seen  was a LeBlonde 12x12 lathe.
I got tasked with doing a post mortem, the machine was totaled ( bent the ways, headstock partial ripped off the ways )
The coupling between the spindle and the speed encoder failed. When the computer saw the speed feedback slowing it tried to maintain spindle speed. There was a 18" 3 jaw chuck with large aluminium pie jaws mounted on the spindle. At some point 10,000 rpm?? one the jaws came off (barely missing the machinist), this cause a huge imbalance at very high rpm, and she tore herself apart.

I've seen two similar cases.
The first was a Mazak quick turn sl-20 running 13/16 x 12' bar stock. The speed sensor failed and all hell broke loose. Somehow a 4' section of the bar came out of the feeder as the spindle maxed out. It beat the entire machine to pieces. there were parts landing over 50' away. Luckily i was standing pretty close to the operator and managed to shove him out of harms way.
The other was a Mitsubishi MTC-10 chucker. They used a scale on the slides with a backup encoder for when the scale got damaged. The machine couldn't read the scale correctly and rapid traversed into the chuck. It was turning at about 4k. Completely destroyed the turret, chuck, spindle and broke the main and the x and z axis slide castings.
I've seen plenty of other crashes as well, but they were caused by operator or programming errors.

[sno_duc]

Ever run a Bullard vertical boring machine. I was introduced to Bullards on a medium sized one 96" diameter chuck. The feed levers were also the rapid traverse, in for feed out for rapid. Any how the journeyman assigned to check me out on the machine, brought the tool down close to the work and then grapped rapid down (oops). A 2" square inserted carbide lathe bit got sheared off, with 200 hp and a massive chuck, it never slowed down (of course 75rpm was top speed, IIRC 1 or 2 rpm was low gear)

[ducpainter]

Ever run a Bullard vertical boring machine. I was introduced to Bullards on a medium sized one 96" diameter chuck. The feed levers were also the rapid traverse, in for feed out for rapid. Any how the journeyman assigned to check me out on the machine, brought the tool down close to the work and then grapped rapid down (oops). A 2" square inserted carbide lathe bit got sheared off, with 200 hp and a massive chuck, it never slowed down (of course 75rpm was top speed, IIRC 1 or 2 rpm was low gear)

The fab shop I worked at had two Bullard VTLs....small ones...4' tables

They would make some chips.

[Popeye the Sailor]

Ever run a Bullard vertical boring machine. I was introduced to Bullards on a medium sized one 96" diameter chuck. The feed levers were also the rapid traverse, in for feed out for rapid. Any how the journeyman assigned to check me out on the machine, brought the tool down close to the work and then grapped rapid down (oops). A 2" square inserted carbide lathe bit got sheared off, with 200 hp and a massive chuck, it never slowed down (of course 75rpm was top speed, IIRC 1 or 2 rpm was low gear)

I used to run one to make the molds at the old shop.

It was old when my dad started off as a machinist.