Honest question about your first cnc crash

ripperj · Feb 17, 2019

Did you feel like puking?

I had a difference of opinion with the control on where the table was going to go when I hit the green button.
Obviously the control did exactly what it was suppose to do and I was too slow to realize we were not headed for home.
Got out of it cheap, a 1/2” long carbide endmill, and a mark on my part that will be hidden when assembled
Wish I had done it before I put new bearings in the spindle(or not at all)

Edit- I know- always Know! what’s going to happen when you hit the green button!

Sent from my iPhone using Tapatalk Pro

edwin dirnbeck · Feb 17, 2019

If you JUST bust a tool of mark a part,it is not much of a crash.Learn and move on.Good luck Edwin Dirnbeck

plastikdreams · Feb 17, 2019

Don't even remember my first crash. Fortunately none of mine have been YouTube worthy lol.

Mud · Feb 17, 2019

From now on, every first rapid move is going to give you the feeling you get on the first big hill on a roller coaster.

plastikdreams · Feb 17, 2019

Mud said:
From now on, every first rapid move is going to give you the feeling you get on the first big hill on a roller coaster.

That's how I feel when operating CNC lathes on first run...those things are just begging for crashes.

cpifer3 · Feb 17, 2019

Puke and move on. It happens. The more you set-up, the more you program,the more you machine, the harder you push, the more chances you have of it happening. Try and understand why it happened , and how it could of been avoided. All that said, yes I felt like puking.

Mud · Feb 17, 2019

What cpifer said, plus Rapid Override is your friend.

DavidScott · Feb 17, 2019

If it is just a tool it doesn,t count, it's not really a crash. Wait until you burry a tool holder into a part, or your vise. It is a lot noisier and you can really feel the crunch in your gut.

PS - If you don't risk at least breaking tools you are wasting a lot of time, tools and collets don't really count, well at least if you don't break too many.

edwin dirnbeck · Feb 17, 2019

I think the worst are cnc lathes with turrets that have multiple tools in the work area even tho they are not cutting. This is the result of old thinking not dying. Production lathes before cnc had indexable turret tooling ,so the cnc lathe maker just followed like sheep. No one would dream of making a verticle machining center with a turret full of tools hanging down into the work area.They would be laughed out of the shop.Oh wait ,I forgot about burgmaster ,what happened to them. Even today you must buy a high dollar Mazak integrix the get a cnc lathe with a toolchanger. Edwin Dirnbeck

Whysosharp · Feb 17, 2019

I remember rapiding a 6FL facemill from home into a part she moved so damn fast by the time I realized some smashy smashy was inevitable. Screwed up the spindle orientation and the home position for the tool changer causing the tool changer to then crash after the fact basically just one problem after another occurred.

DDoug · Feb 17, 2019

edwin dirnbeck said:
I think the worst are cnc lathes with turrets that have multiple tools in the work area even tho they are not cutting. This is the result of old thinking not dying. Production lathes before cnc had indexable turret tooling ,so the cnc lathe maker just followed like sheep. No one would dream of making a verticle machining center with a turret full of tools hanging down into the work area.They would be laughed out of the shop.Oh wait ,I forgot about burgmaster ,what happened to them. Even today you must buy a high dollar Mazak integrix the get a cnc lathe with a toolchanger. Edwin Dirnbeck

I'd like to see YOU design, build, and sell a machine tool..... :toetap:

litlerob1 · Feb 17, 2019

Busted Tools, even fucked up parts are not Crashes. Crash is something that effects the operation of the Machine Tool. Maybe I'm just saying that because of how many Tools I've busted.

Recover, recover, recover. Don't just stand there like a dope, start working on it. Tear the set-up out to get it on another Machine, start tearing Tools out, to inspect, don't let the crash immobilize you.

R

Fancuku · Feb 17, 2019

My first crash was with an Okuma mill at school. Lets just say it took me another month or two to fully understand why it happened.

DouglasJRizzo · Feb 17, 2019

ripperj said:
Edit- I know- always Know! what’s going to happen when you hit the green button!

One thing I teach all my students - Single Block/Rapid Down/Hand on Feed Over ride.

Make an offset change? See above.
Make a program change? See above.

I've crunched tools and scrapped parts, but I've never buried a spindle, and hope that it never happens.
However, if it does, I'll learn from it.
Do ye likewise.
Don't fret over it.
Just learn from it.

CarbideBob · Feb 17, 2019

"Did you feel like puking?

"

First, scared from the noise like when someone pops a bag behind your head.
Second, the rushing thoughts and fears of "How am I gonna make it so that the boss does not know about this".
Third, the sick feeling starts to sink in.

After enough years and oops #2 and #3 go away and you are left with the jump and the "What are unhappy with this time you stupid machine".
I've buried spindles, I've ripped ballscrews mounts off, I've split V-6 engine blocks in half, even had a SG table end up on the floor.

Chit happens.
When you have people try to remember all those feelings when one of your employees does the same.
(yes, I know, hard to do when seeing a 10-40 large bill due to a brain fart)
I've had people offer to resign over a big oh-shit. "Not a chance,.... we just invested a wheelbarrow full of money in teaching you what not to do".

Rumor has it that there once was a guy who never did such. They then nailed him to a cross a while back.
In the racing world they say that if you do not crash you are not trying.

We all screw it up once in a while so don't feel bad. A new lesson, a new day, the sun will rise tomorrow.
This may be your first "machine did not do what I was thinking". If you keep doing this stuff it will not be your last.

Mostly to say you had a crash and that sick feeling in your gut. Sorry to hear but welcome to the club...... :cheers:

Bob

EmGo · Feb 17, 2019

Wait until you guys set up a Gleason. Those things are a mechanical crash just begging for a place to happen. And they don't have feed overrride buttons. I like the 22'es especially - it's either right or it's bye-bye thousand dollars kerwhang. One try. And no way to test before pushing go.

Spruewell · Feb 17, 2019

I’ll never forget my first crash. Was running a roughing cycle in my new VF3 and tried uploading another program to memory mid cycle. Machine stopped and threw an alarm. I cleared the alarm, finished uploading the program and hit the green button to resume machining. Spindle went rapid -8”. Unfortunately my 6” teco double station vise was 6” below the end of the 1/2” carbide end mill. I still have a chunk of carbide lodged deep in the aluminum center jaw as a permanent reminder. Upshot of that is I was able to turn that tool holder into a dedicated tool for calibrating my wips.

Delw · Feb 18, 2019

I was just learning like very 1st day 1st couple hours how to run a HES cnc way back when late 80's. the guy showing me didn't put the correct tool on. he hit the button and walked off. 30 inches of very slow travel maybe 100IPM rapid on a 3" dia boring bar 6 or 8 series cnmg insert into a 28" dia 6 inch long titanium seal for a garrett APU.
I just sat there and watched, had no clue what the heck was going on. was the slowest crash I ever saw in my life took out the tool the holder the part he fixture the extended chuck jaw face plate and a hole bunch of other stuff. all this and the chuck spinning at a whopping 10-20 rpms
the control box for those who remember then was a old numeratic that stood on the side of the machine about 5 foot 2foot wide tall with lots of led lights.

was like watching a train wreck in slow motion.
guy comes running back from inspection with half the shop yelling oh f*** oh f***
on the bright side they ended up retrofitting that machine, put a 6" spacer block under the head for more dia clearance and raised the tool post 6" taller,a fagor control and when it was done I had a brand spanking new machine to learn on. we had 3 of those machines. slow as crap but cut inco, waspaloy mars hanse like butter.
oh the good old days

Jaxian · Feb 18, 2019

I have to admit I am VERY cautious when running lathe programs the first time. Single block, feedrate override, rapid override, do the whole thing like 10" out from the chuck. I kill the coolant, use Optional Stop just to make sure everything is going where I want it on that next tool change.

I am not a machine repairman nor do I want to learn to be one. I must admit the first time I run a program for real and can hear it running that 12" power chuck up to 3k rpms with the coolant hitting it my heart is beating fast. Stupid little single window is completely obscured and all the lights I put in there don't help at all. I sit there with my hand on the Cycle Stop button the first time just kind of listening for any sound or vibration that seems wrong. I did manage to stop one too long drill accident with just a bent arbor and some skid marks on the soft jaws.

That said it's the stuff you don't expect that makes me jump. I had a full load out of boring bars and drills but wasn't worried I just needed to switch it from low gear to high gear in MDI before running the program. Stupid CAM software doesn't put in gear changes.

I hit M41 and it does the little click and slow 45 degree rotate like it supposed to then for some reason it indexed the turret. Only MDI input was M41;. Shouldn't have done that, the longest tools missed the jaws by like 0.1". Still have no clue why it did that. I just make sure the turret is homed when I do gear changes now. Of course never seen it do that again.

AD Design · Feb 18, 2019

Sure do remember, "you always remember your first". Big (for 1982) White-Sundstrand NC tape reader with a GE control and a "bubble memory". The RAM EDM guy was waiting for an electrode I was machining and attempted to go to home position through the vise mounted to the tombstone. Yes I felt like puking and then had to notify the boss. This isn't a career for the faint-of-heart or the easily discouraged. We've all committed expensive machine atrocities and had to make the choice of repair/learn or get out of the trade. It's not an easy choice to make, made even harder if you have to suffer the embarrassment of telling your wife/friends/family that you f'ed up and lost your job. IMO it takes a real act of courage (if you care about your work) to walk back into the shop, hear the murmurs of everybody, and walk up to the machine you crashed with the intent of being better than you were the day before. If you're going to remain in this trade you're going to have to gather your courage, take the heat, and move forward from this. Even some of, what I consider, more knowledgeable members here have posted their own horror stories and continued in the trade. Sorry to hear this happened but survive the incident, take the precautionary measures others have posted, and learn from the mistake. Machines can be repaired, human bodies to a lesser degree so be safe with yourself too. Welcome to the club, glad to hear you weren't injured. Good luck.

Honest question about your first cnc crash

Stainless

Hot Rolled

Diamond

Diamond

Diamond

Cast Iron

Diamond

Diamond

Hot Rolled

Cast Iron

Diamond

Diamond

Cast Iron

Titanium

Diamond

Diamond

Hot Rolled

Stainless

Stainless

Stainless

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