O/T Thump and Bump

[chris m]

Here's my most recent crash story, from, ah, today...

 

One of my guys just made our Hardinge Conquest T51SP lathe into an anchor by rapiding a tool into the spinning stock at full-throttle, neatly breaking the turret mounting plate on one corner and lifting the turret up about .030"

 

Didn't know it was that bad until after I had taken the entire front of the machine apart (about 6 sheet-metal panels and about 1,000,000 button-head screws) to gain access to the turret thinking that we 'd just have to line it up; then I took off the cover to access the turret mounting bolts and

 

Doesn't help that its the busiest machine in the shop...

 

Anybody hoarding Hardinge parts?

 

 

Please share with me some amusing anecdotes so I don't feel so bad

 

C

 

[ 03-11-2003, 05:23 PM: Message edited by: chris m ]

[Guest CNC Apps Guy 1]

Haas did the exact thing you speak of to one of their Mori Seiki Lathes a few years back. "It just happened..." Nobody saw or heard anything.

 

Anyway, Mori was able to bring it back to life... for a price. About $32k if memory serves me.

[Allan]

Are you saying there are no turret mounting bolts?

Is it all one piece? There must be some shear pins in there someplace!

I was parting off some tube stock once 14" dia OD 12.875 ID 12" from the chuck.... Blade was pretty thick .156 or so. It grabbed and launched the door off the old Mori. I figured no biggy, reset everything ran the boring tool, turning tool, sizes were funny, changed offsets. Ran the part off tool again, door flew off! I decided to clock up one of the tool holders on the turet, it was out a mile. There were alum shear pins on that turet, sheared of course they even had a tapered pin hole in there so you could get it back into location without much trouble. Good luck on the hardinge.

 

Allan

[Brendan P]

Hey Chris,

Just curious,was it because of a program error

on your part,or he set his (tool/offset) wrong?

If it is a brand new program,the operator should

at least give you the benefit of utilizing that

rapid overide switch!

 

Any time that I ever got cocky on setting up a job,you got it....CRASH!

I also learned that when the little voice inside

your head asks if you remembered to set your tool

just as it is approaching the stock.....

LISTEN to it!! (I swear by this one)

 

Sometimes it is of great benefit for the operator

to dry run the program,in the long run it can

save a lot of $$

 

It happens to the best of us Chris!

[jeff]

BucketHead,

Those are some good ideas,but dry run doesn't tell you that you are gonna crash.

lol,I know for a fact.

[Keith Graydon]

I never met a machine that I couldn't stall.

-Keith

 

('tho i'm very easy with them)

[Brendan P]

Jeff,

I am not talking about hitting the "dry run" button!

I am talking about (cycling thru)the program,

maybe above or away from the part.

If there is a "funky move" in the program,this

is where you are apt to catch it.Not after the

fact!

It sounded to me that chris'"crash" happened on

the tool aproaching the stock.

On aproach,I always single block and turn rapid

down,then watch distance to go on pos. screen.

If you program .100 away,and it says you got 1.250

dis. go,well you better check your tool setting or

something!

These are the things I am talking about.

Perhaps I shouldn't have used the term "dry run".

[chris m]

quote:

---

Are you saying there are no turret mounting bolts?

Is it all one piece?

---

No, in this case it is the lower (ram) turret that had the collision. The turret is bolted down with 4 bolts to a mounting plate which is in turn bolted to the carriage that rides on the guideways; one of the "ears" that holds the bolt sheared right off the plate. From the look of the break, its been cracked for awhile and gave it up this time.

 

The chances that they have that one on the shelf... NOT good

 

quote:

---

Just curious,was it because of a program error

on your part,or he set his (tool/offset) wrong?

---

It was a proven program, the offset was entered wrong (about 4" wrong) and the guy didn't walk the tools in on the approach moves the first time through the program.

 

WHAM!

 

I always tell the guys "Distance to go is your friend"

 

Maybe I'll post a picture of the pile of parts we have growing next to the machine as we take it all apart; the whole front of the machine is off, the turret is off, the mouting plates are off, it looks like a disaster area.

 

C

 

[ 03-12-2003, 09:59 AM: Message edited by: chris m ]

[Tony]

"Distance to Go"

Has saved me More then anything else

At the Machine.

[G Caputo]

Distance to go used to be my best friend, we have always done are programming at the machines and we would generate anywhere from a 50 - 3000 line program using heidenhain conversational programming. Mastercam generally adds 5-10 times that amount, so single blocking won't be an option.... so it's gonna be full sequence, stand back, and order some extra face mills. How about doing a datum shift (offset?) and hitting the rapid overide button? That would allow you to run the part quick and see something out of the ordinary... Just a thought.

[Rekd™]

quote:

---

and the guy didn't walk the tools in on the approach moves the first time through the program

---

When I see a person doing that or something along those lines, they are no longer permitted to make ANY adjustments, changes, edits or nose pickin's un-supervised until they prove they can do it safely. This kind of behavior ranks right up there with driving a car while drinking; it's dangerous, stupid, and should not be tolerated.

 

'Rekd

[Trevor Bailey]

Most agreed 'Rekd. I just so happen to be walking by one of our machines yesterday and looked up at the code as the tool was approaching. Lets just say that the tool did not stop at the programmed approach height. I was able to hit feed hold in time and save the fixture/part. The program is proven and has been saved with all respective offsets back to the computer. The operator loaded the wrong offsets for this particular program

 

I really wanted to see my hands around his neck for that one!!!! I can not and will not put up with mindless mistakes.

[jeff]

BucketHead,

I figured that out after I posted my reply.

I didn't mean to sound rude.

[Tony]

"First piece"

In my post I can toggle a M01 @

Every tool change .Then Distance to go

Can Babysit my program while actually

Making a part. (No dry run,No Z offset)

 

[ 03-12-2003, 12:20 PM: Message edited by: Tony ]

[Brendan P]

No offense taken Jeff.

I figured that it was misunderstood by the

way I worded it!

Anyone who sets his tools for a job set up and

just "lets them go" is a moron. (IMO)

[chris m]

We now have the lower turret of the machine completely apart and everything laying on the floor; what a workout! Hardinge hasn't been able to put their hands on a replacement part, and even if they could getting the center height right would be a bitch, so...

 

We have decided to re-locate the bolt that used to sit in the broken-off section by about 2" and drill and tap another hole in the turret to match, then throw it back on; can't break it any worse

 

Still working on the photo.

 

C

 

[ 03-12-2003, 01:02 PM: Message edited by: chris m ]

[J Coulston]

quote:

---

Those are some good ideas,but dry run doesn't tell you that you are gonna crash.

---

Dry run just helps you crash slooower. With dry run on you might just crash a little bit. Helps relieve some of the pucker factor.

 

John

[jeff]

We have a Leadwell ATC50 cnc lathe that the turret just fell off!

It wasn't even during a cut.

LOL what a junk machine.

The turret plate was c/bored leaving only a 1/8 wall thickness for strength.

And after 5 years and a few crashes(none by me of course) ,it just let go.

The only good thing about this monster is that it turns 36" dia and 10ft long and has a 50 hp motor,and weighs 50,000 lbs.that's about it.

Stay away from Leadwell!

[Cg]

ai feel for you.

Just had the exact same thing done to me by my lead man of 10 years. New machine with less than 100 hours on it, ran a program off a smaller machine didnt check clearances of the turret smashed the turret straight into the chuck full rapid.

 

I looking at the bright side that it was on my Hass and not any of the Harding or Mori seiki lathes that we have

 

oh , did I mention he came in the next day and quit " wants to look for a position at a big company where he wouldnt have the responsibility of running the owners machines"

 

Cg

now looking for a new programer/setup person who wants the responsibility and a job

[chris m]

OK

 

I put some images on the ftp, is there a way to display them on this page?

 

Rework is underway...

 

[ 03-12-2003, 04:56 PM: Message edited by: chris m ]

[Rick Damiani]

Ifn you don't mind, I'd like to use these pictures in my class. They will make a great addition to my other lathe training aid: a split-in-half HAAS lathe tool holder.

 

Anyone else with photos of spectacular crashes feel free to send 'em along. It will help me turn out better operator/programmers.

[Jack Mitchell]

Alright guys, here’s the kicker.

 

I am without a doubt, the sultan of crash – do you have any idea what it feels like to have the guys in the shop ask you if the machining center is a cnc punch press?

 

These things occurred 20+ years ago – please be assured if there is any method known or unknown, then I have smashed it – this includes the tooling on consignment from the cutting tool distributors.

 

I am without a doubt an expert on crashing nc and cnc machine tools – inadvertently this also makes me an expert on how not to crash a machine tool; I teach this to students all the time and I hammer home the fact that I am indeed a proverbial expert of crash and that if they listen to me then they will also become experts at how not to crash.

 

Dry running a workpiece holds no validity for me; it might be a famed response but I still say launch it every single time – just my own personal spin on the topic.

 

Funny thing was two weeks ago I told the operator to launch it – I also cautioned him to be careful; wouldn’t you know it that I made a mistake in the program and the poor guy actually fed the tool into the soft jaws on a brand spanking new Haas SL30 at .03/rev; he was not amused nor was his supervisor – everybody in the shop commented on the crash.

 

Sometimes I can be such an assh___, but I did immediately admit the crash was my fault.

 

Regards, Jack

[chris m]

Rick

 

Its fine with me if you use them. I didn't want to put a folder on Jay's ftp so I just dumped them out there; I tried to rename them so they all started with "Hardinge" but I don't have permissions for that so here are the names:

 

Disassembled 5.jpg shows the machine torn apart

Missing Piece 3.jpg shows the part that broke off

Ram Turret Out.jpg shows the turret sitting on the floor

Rework 1.jpg and Rework 2.jpg show the turret mounting plate up on the DPM where I'm reworking it. The turret itself will be up there next!

 

I'd like to have them in my post but I can't figure out how to do it; I've seen it on this forum before though.

 

Jack

 

At least you owned up to it; nothing pisses me off more when a guy says "it just crashed" or "I don't know whats wrong but I had to offset all my tools .030", SOMEONE must've bumped it" or "the machine didn't do what I told it to"

 

My all time favorite is when a guy makes a tool-offset or program edit error and whacks the machine, then fixes their error and says "everything is right, the machine must be screwed up"

 

Suuuuuuuuuuuure

 

Rework is continuing

 

C

 

[ 03-13-2003, 07:23 AM: Message edited by: chris m ]

[chris m]

The rework of the parts is complete; just need some replacement parts from Hardinge now to start reassembly

 

I hope to Christ this works

 

C

[cadcam]

Chris I put a folder called "Crash test pics" in the same Dir and all of them are in there.