Worst crash ever?

[Bob W.]

Lol!  I figured this would get some views.  I'd love to hear some stories of the worst crash you have ever seen.  What was damaged?  What was the cost to repair?  What was the cause?  I'm pretty careful at the machines but I figure reading some of these stories will scare me straight so I will run them like it is my first time. 

[Tinyfxds]

A 10" face mill z dive into the part at rapid from a foot away.  Tore every key on the spindle that horizontal had on it and snapped half of the flange on Cat 50 holder off.  That was probably the most violent.

 

The most expensive was on our Kuraki horizontal.  A 6" face mill with our "W" quill extended out 16" milling out a large bore and the side of the spindle rubbed on the inside of the bore.  It put an .125" deep by 1.0" groove in the quill.  Those quills happen to be precision ground and fit to each machine.  The cost was about 200,000 for a brand new one.

[Newbeeee™]

Bad juju this thread...

[Joe788]

The cost was about 200,000 for a brand new one.

 

Holy xxxx.

[Bob W.]

Bad juju this thread...

Only if you laugh 

[Del.]

Hard to have a violent crash on wedm, but one time I was wiring a part and I took a piece of carbon with some glue to hold the part. I was gone for lunch and the wire broke and went back to start point and when it got back to carbon it broke the entire upper head off. It was just hanging by the wires. It actually kept burning but part looked like i did it with an etch a sketch. That carbon glued on part never did let go. Had to beat it off with a hammer.

[specv]

4 inch facemill on the side of a casting, the operator was jumping around in the program and hit cycle start, the z was off at least 2 inches. the facemill sheered both keys off and welded itself into the spindle. the spindle was removed(with the facemill still attached) and replaced @ about $30k.

[crazy^millman]

Too many to talk about. I have never seen someone die from an accident, but had one guy bounce around inside of a VTL one time and get spit out like a gumball. He was pretty beat up, but he came back to work about 6 weeks later.

[kccadcam]

I've seen enough crashes that I don't need to see anymore....

 

Makino A55 -  2" Mitsubishi facemill at 20000 RPM - 350 IPM

Operator put left hand blank in fixture instead of right hand blank.

Rapid down in Z, ripped the holder out of the taper and destroyed the spindle.

Broke the tempered safety glass window,

beat the hell out the internal sheetmetal as it bounced around.

I was upstairs in the programming office and the floor shook..........

About 50k to fix..........

 

 

Mori Seiki SL-35 lathe

Operator sent a rather large boring bar rapiding into chuck at high speed.

When we finally got there the operator was white as a ghost and puking on the floor.

The turret was laying in the bottom of the machine!!!

Broke the ball screw and the ways!!!

Machine was a total write-off...................

 

 

I could go on and on, but like newbeee said,,,,, bad juju.......

[YoDoug®]

Over the years I have seen quite a few. Recently saw a machine crashed so hard it cracked a casting.

 

Not too long ago I saw the aftermath of a 3 ton weldment dropped 5 feet onto the table of a twin column vmc. Every roller of the tables linear guides made a little dent in the base.

[Newbeeee™]

Only if you laugh 

Oh yes, laughs the man with vericut!

[Matthew Hajicek - Singularity]

Years ago at another company they had a brand new Mori Seiki lathe with live tooling.  I was working late programming when I heard a boom and the building shook like a bomb going off.  I later heard that the turret had been rapid fed into the chuck near max RPM.  Two weeks, $20k, and a new night shift lathe guy.

[The Cathedral]

Had an operator run the spindle warm-up program on an HMC with a 10" long Allied inserted drill. Once it hit 15,000 rpm the drill came out of balance, bent then sheared off and flew out the back of the machine. Straight through the sheet metal all the way. He was standing at the control panel; had the drill decided to fly towards the front of the machine instead, it would have been bad.

[TheePres]

Have any of you ever tried spinning a 13" long hollow tube carbide tipped gundrill @ 15k outside of hole? Robin Hood would have been impressed.

[kccadcam]

Just hit one too many zeros in MDI with your edgefinder. (shoulda been 1000...)

at about 5000 RPM a Starret edgefinder spring will let go......

(about 10" long at that point)

Like a bullet........

[Mick]

Inexperienced operator restarted an operation on a horizontal. Operation was boring using a 8 inch boring head, which should have been running at approx. 200rpm. He restarted at a spot drilling operation, which had a start up RPM of 5000rpm.

The heads of the cap screws fastening the boring tool sheared, and the tool smashed through the cabinet, almost (really, almost), taking the guys lower jaw off. The nightshift supervisor heard the bang, and ran around the corner to see the guy clutching his jaw, laying on the ground in a pool of blood. The guy was in intensive care for weeks, had massive scarring, and ended up with permanent brain injuries.

 

He was reassigned to another department when he returned to work months later. He left a couple of years later. Sadly, he ended up in prison a few years after that.

[specv]

Have any of you ever tried spinning a 13" long hollow tube carbide tipped gundrill @ 15k outside of hole? Robin Hood would have been impressed.

YEP, I keep it in my desk drawer for a reminder!

[Sticky]

Have any of you ever tried spinning a 13" long hollow tube carbide tipped gundrill @ 15k outside of hole? Robin Hood would have been impressed.

 

 

Ahhh yes, my favorite Mastercam bug to date. I was using a 12xD or longer drill to make a hole, on the side of a part on a tombstone, after the I drilled the hole, I put it in single block to make sure it retracted to the clearance plane and didn't hit the part sitting at B0. The machine was doing a zero return and M5 was called, at this point I figured it was safe to open the door to verify that everything was still cool (machine is heading home with the spindle off), as soo as I open the door to peek in the spindle ramps up to 9k+rpm   Just barely missed my head as the drill bent 90*

 

Between in In-House and I we never could figure out why that drill operation did that. Scary as sh*t though.

[Tinyfxds]

I forgot one.  A different Kuraki horizontal.  New employee and the trainer were standing across from each other in front of the control panel ( so they would be standing on the side of the spindle.)  They had a 20" Graflex boring head in the spindle and the newbie accidentally hit spindle start.  The last program was set to 4000 rpm so that is what the boring head tried doing.  Before they could stop it the balance weight block flew off the boring head, thru the safety glass of the door, went between the two guys, sheared thru a sprinkler pipe in the ceiling and punched a hole in the roof.  If that would have hit either of those two guys, they'd be dead.

[Tinyfxds]

Ahhh yes, my favorite Mastercam bug to date. I was using a 12xD or longer drill to make a hole, on the side of a part on a tombstone, after the I drilled the hole, I put it in single block to make sure it retracted to the clearance plane and didn't hit the part sitting at B0. The machine was doing a zero return and M5 was called, at this point I figured it was safe to open the door to verify that everything was still cool (machine is heading home with the spindle off), as soo as I open the door to peek in the spindle ramps up to 9k+rpm   Just barely missed my head as the drill bent 90*

 

Between in In-House and I we never could figure out why that drill operation did that. Scary as sh*t though.

I had this happen with a very long solid carbide drill.  Deep cycle drilling on our Okk VM7.  Drill came out of the hole, I opened the door, I hear the spindle ramp up to 6000 rpm and watch the drill start to vibrate and whip out.  Just as I get the door closed, I hear junks of drill hit the glass.  That was a little too close

[Robert Ouellette]

worst I saw was on one our larger Matsuuras. operator had to skim the new aluminum subplate. put in an 8" Hertel facemill and proceeded to hit the spindle forward button. but I guess you all can guess what happened next. last programmed spindle speed was 15k. 8" Hertel is only rated for 5k. all 8 inserts let go. every single one of them went through the sheet metal and bounced through the shop. 1 of them went through the exterior wall. through the garbage dumpster. and was found embedded in the steering wheel of the owners BMW. He got in his car at lunch and grabbed the steering to drive away and he found it. it had gone right through the car door and stopped in his steering wheel. the operator was the luckiest guy in the world. lucky it was on the biggest, therefore tallest, machine in the shop, and the spindle was at home position, so they flew right over his head. the flying inserts made a real nice sound bouncing through the shop. no one was hurt or even hit by any pieces. luckily. that was the worst I have seen.

[Bob W.]

I modified my post by adding a S50 right before the M30 at the end of the program.  I spooled up one too many items to 12k rpm because that was the last programmed spindle speed.  ALL of my posts have this addition.

 

S50

M30

[Karl@CP PISTONS]

Worst was BRAND NEW horizontal, Forman ran 6" face mill into tombstone at full rapid. Hit so hard the tombstone was knocked over inside the machine. Had to get the forklift to lift it off before any repairs we even started. Just about every piece underneath the tombstone had to be replaced. I heard it was $80,000 + in 1990 dollars. Everybody in the shop thought it was a car crashing into the shop.

[huskermcdoogle]

I spun a stylus off a probe once due to the previously programmed spindle speed, luckly I hit reset before it go to 12k or I might have had a probe fly off as well.....  Needless to say, I added an S100 into the tool change macro.  That one didn't cost too much.  A week before that though I had cracked up the spindle in that machine pretty bad.  Only flying stuff for that was the tool holder flying out of the machine, flung by one pissed off programmer after he saw the condition of his taper and the changed code in an unchanged portion of the program.

[Zoober]

Two bad ones come to mind....

One, I was crawling around under a new machine install leveling, when a bomb went off. The Niigata next to the machine I was leveling sent the side of the spindle into the tombstone, knocking the tombstone off the pallet, shearing all bolts.

Second, our night crew threw a 62" multi thousand pound part off of a VTL. completely trashed the guarding off the machine, and killed a Bridgeport and saw with the spinning part.