O/T Timid operators

[roy g. biv]

I had a slightly differenet problem at my previous employer. The lead man on second shift was notorious for setting feeds and rapids to 25% as soon as first shift left. I caught him red handed several times and all he could say is "No comprendo". It was amazing how his almost perfect english would disappear when he was in trouble.

 

Once my supervisor and I witnessed him going after all the tools in the ATC with a ball peen hammer.(All Carbide tools, Ping, Ping, Ping) When he came into the office and said a program that ran fine for a week suddenly went to hell, my sup. said "yeah, I guess we should take that hammer cycle out of the program".

 

All he could say, "No comprendo".

 

When my sup. went to the plant manager about the situation, he was told "So what, he's been here 20 years. Leave it alone."

 

Sorry for the epic, but this situation still amazes me.

[MetalMarvels]

quote:

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OUCH!!

 

Its amazing how far an 1-1/2" inserted endmill will throw a piece of stock; isn't it..?

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Really makes you DUCK also - not to mention the nasty dent in the sheet metal.........

 

[ 09-10-2002, 12:05 PM: Message edited by: MetalMarvels ]

[chris m]

It really makes you appreciate the full sheetmetal enclosures on newer milling machines! Those 6" high "guards" on the older Matsuuras are a joke

[Roger Peterson]

Why whatever are you guys talking about. I'm sure you are the only ones to ever have this happen. I know it has never happened to me as far as you know.

 

[mold100]

Amatuers (JUST KIDDING), if you think a 1&1/2 incher can throw a part,try a 3" sandvik coromill

.1 depth of cut,1440 rpms and 91 ipm.Let it start milling it will sound good after gets into cut,NOW have

the apprentice filling your coolnt turn off your magnet,but make sure there is a customer about 10 feet away.I will gaurentee a 3 foot jump when you feel the 240 lb. of PX-5 flies of the magnet and lands solid on the table.While it is in motion be sure the cutter picks up and rapids at 1900 ipms back to the start of the cut also helping propel the block.I really dont recomend trying it,trust me its not a good thing.Also the above cut runs well in our 40 taper Makino V55 around .01-.013 chip load at around 1100 sfm.However our 8 year old Hurco 40 taper with more travel cant take this cutter at all.I believe there are conditions for every tool and material,Machine,Cutter dia. and length,tool coating are all factors.But sometimes you gotta pushem to see.

[chris m]

Corey- that's a good story, it could only be better if there was a big dent in the sheetmetal so when you bring people around the shop you can say "see that mark there..."

 

quote:

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But sometimes you gotta pushem to see.

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That's for sure! There's nothing better than that wide-open powerboat sound you get when a milling machine is plowing through a rough chip at 4000 RPM, 100IPM with a nice heavy chipload; GOOD stuff!

 

[ 09-12-2002, 07:24 AM: Message edited by: chris m ]

[McRae]

I love the smell of coolant steam in the morning...

[David S]

quote:

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I was just wondering whether any of the board have experience dealing with operators who are afraid of loud and aggressive milling and who make HSM difficult. Anybody?

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If I tell you people that I have a coin with heads on both sides, you must say:" You are kidding."

 

OK, let me reverse this question:

 

"I was just wondering whether any of the board have experience dealing with 'smart' programmers who love loud and aggressive milling and make HSM on every thing. Their programs wear out my tool so fast and break them. I have to change tool and restart cutting so often that make my job so difficult. Anybody?

 

Yes, they show me the first time when tool is sharp. With their 10000000 rpm, tool wears out, breaks and is flying all over on the third part. You bet I am timid. More timid is they are going to lock the program that I cannot change it while they are sleeping at home.

 

Hey, guys I am not UNIN worker. I work hard. With slower speed I can give my boss 20 finished parts at my shift. However, with their HSM I can only give him 4 parts along with 5 broken cutters, 3 unusable blocks material and 2 dents on the VMC. Tell me what to do. I do not want get fired."

 

My point is: be nice, be fair and be patient. Do you have first time? Do you have children?

[Scott Bond]

quote:

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I was just wondering whether any of the board have experience dealing with operators who are afraid of loud and aggressive milling and who make HSM difficult. Anybody?

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Hi

My best HSM, I had a fixtured part with 2 1/4" dowels and a dozen 1/4"- 20 bolts around the outside of the part.Using a 5ax cin. at 250 IPM in a 2-d style . The Operator forgot to put the bolts in on part number 15.

My normal style of work would have ripped the part out. With less torque of the part do to the HSM style, the part stayed on just the slip fit dowels, and the slight vacuum of the coolant.

If a timid operator could experience this type of cut (mistake) and still have a good part, I am convinced he would no longer be a timid operator.

 

[ 09-12-2002, 09:48 AM: Message edited by: Scott Bond ]

[jspangler]

Hi

Not that this really applies, but i figure i lost about 6 Mos. time learning MC and CNC machining, just by having people unfamiliar with CNC machining come by the shop to check out my new toy. I was running some parts that James M. had drawn up for me, and everything was working fine. ThenTHEY scared the hell outta me " Whoah!! Slow that thing down!! You're not supposed to run the tools that fast! You're running the tools the wrong way!, you need to learn on a reguular mill before you wreck this thing", Etc.

 

Fooey!!

 

So, of course, i slowed everything down using the feeds and speeds out of the Machinist's handbook ( they recommended) and wasted tons of time. Nevermind that i had been set up with Insertable tools on a tooling package with the machine. I finally got fed up that my $70k investment was putting out about 2 crappy parts an hour, and even with 6 mos. experience I knew that wasn't right. I reposted form the original drawing. I haven't looked back since. I still scare my Dad, but when I pull the parts off the machine, he just keeps his mouth shut..

 

Thanks

 

John

[Guest CNC Apps Guy 1]

See, what a lot of people do not realize is that when cutting steel, with CARBIDE, the chips are SUPPOSED to be Valenite blue. That means that the heat is going into the chip and not in the part or the tool as much as it would otherwise. The only acceptable wear on a carbide tool, which is also not often realized, is flank wear. Chipping, cracking, cratering, etc... all bad. Now if you're getting excessive flank wear (i.e. after 5 parts instead of say 20), then drop the feed down about 10%. You have to know you're tooling, your machine, and the process. HSM is not always about max RPM (though in Aluminum it often is Max RPM) but it's about Cubic Inches per minute. Often times it's faster to take a shallower depth of cut with a greater width of cut and faster to achieve a faster MRR (Metal Removal Rate).

[TheePres]

James,

Do you know of any websites, literature or other info to learn these HSM techniques. My boss has been impressed by these methods he sees at Tool Shows, and wants me to steer away from my trusty 2.00" Hoggers.

[Mic6]

This is a great thread. How bout we ressurect it.

[Guest]

Here's a link I posted previously about High Speed machining techniques

 

Linky

[Thad]

Before I realized it was an old thread, I thought Rekd was having another baby and didn't bother telling us before announcing it to Trevor!

 

Thad

[Guest CNC Apps Guy 1]

Yeah, 2002... WOW, that WAS a long time ago.

 

I guess what I would have to add to it now is "Get to know your machine". Find out what it likes. Every machine has a sweet spot where it performs better than usual. Find it. It'll take some time. You may need to do some experementing but now in the slow economy, if you have any spare time, shops should be using this time to improve their skillsets to prepare for the next boom.

 

JM2C

[mcpgmr]

I do all the one off stuff from program to finish part at the shop I'm at now. I'm on the floor only a few times a week when something needs to be done asap. Just the other day I had a totally non experienced operator come running over to my machine and rip the doors open to see where the noise was coming from. He got soaked with coolant and I just looked at him and smiled and chuckled. I didn't have to say a word. It was obvious he felt stupid as he walked away dripping. Later on he asked me what I was doing wrong and if the part was ok. I explained to him that most times "Noise = Profit" and that you can't always have the ideal cutting conditions. I had a .500 HSS E.M. with 3" L.O.C. in an extended length holder cutting aluminum taking 2.5 D.O.C. at 30% radial D.O.C. I had to get in and get out or it was going to take forever. Sometimes our customers are expecting their parts to be at the race track in two days or less so time is critical. Now the next time this guy rips open my doors I'll rip him a new one. I figured he deserved the benefit of the doubt the first time.

[iowajim62]

Paul,

That story reminds me of a time that a fellow programmer came running over to a big mazak horizontal that was roughing at 12000 rpm and 800 ipm with a 2" iscar insert cutter and pulled the door open, not only did he get soaked but he also got machine gunned with a stream of bullet chips starting on his forehead and going diagonally across his body and arm. Needless to say he didn't do that again.

[Guest CNC Apps Guy 1]

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...he also got machine gunned with a stream of bullet chips starting on his forehead and going diagonally across his body and arm...

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This seems like a VERY good reason to leave the machine door interlocks in place. It's usually people that have no clue that get themselves hurt. He's lucky he was not seriously injured.

[Bruce Caulley]

quote:

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quote:...he also got machine gunned with a stream of bullet chips starting on his forehead and going diagonally across his body and arm...

 

This seems like a VERY good reason to leave the machine door interlocks in place. It's usually people that have no clue that get themselves hurt. He's lucky he was not seriously injured.

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Idiot. And a big +1 to door interlocks.

 

Most aggressive cut I have done was in 7075 with a 63mm iscar Helialu at 25000RPM, 6mm DOC, 45mmWOC and 10m/min. If someone had opened the door and been hit with that stream of chips, we would still be picking bits of him off the opposite wall.

 

Bruce

[Greg Williams]

quote:

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not only did he get soaked but he also got machine gunned with a stream of bullet chips starting on his forehead and going diagonally across his body and arm. Needless to say he didn't do that again.

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This is why Lions sometimes eat there young

[kunfuzed]

The thing that pisses me off is when operators pull the longest f-ing tool they can and stick it in the longest f-ing holder they can and then blame you for programing it to fast! Or if it screams then they just drop the feed percent and not the spindle in addition!

 

 

I do my best to give setup info when necessary. But sometimes its just a simple one-off piece of tooling that they should be able to use there head to pick the right tools!

[Guest CNC Apps Guy 1]

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...they should be able to use there head to pick the right tools!

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You'd think anyway... but there's a reason they are OPERATORS and not Machinists or Programmers.

[chris m]

Have these door-pullers not heard of Feed Hold? If you thought something was amiss in the machine, WTF do you plan to accomplish by sticking your head into it? If one of my guys ever did something like that they'd get a day off if we didn't fire them first; that's just stupid.

[Toby-Axis]

I' couldn't agree more. It pains me to see operators change the feeds and speeds lower because they want OT or even worse so they have time to walk around and chat all day.

 

Time is MONEY especially when we are competing with Overseas Companies.

 

Operators are there to CHANGE PARTS and Set-Up Jobs, Not to Change Planned Tooling, Programs, or Machining Methods.

 

All to many times I have selected proper tooling, programmed, and methodized to find some operator changing things around for the worst, not better.

 

You hear "I have 27 years experience and in all my years I have never seen anyone write programs with those extremely high Feeds and Speeds".

 

The Bottom Line is that they are Operators for a Reason. Even a True First Class Machinist knows Machining Economics and will INCREASE FEEDS & SPEEDS according to Tool, Material, Set-Up and what the Machine will handle.

 

I've got Operator from Grumman that cringes at 380 IPM and 8,000 RPM in Aluminum 6061-T6. These are SLOW compared to what you guys do, but it's all the machine will handle using G5.1 Al-Nano HSM. I love watching him get pissed at me.

 

Someday I pray to work in a shop that is 100% automated with Modular Set-Ups and Standardized Tooling in the Magazines.

 

Seems to be the only way to keep Operators from messing with ECONOMICS!!!!!!

 

Rekd you have a great way with words and setting the Operators Straight.

 

STFU, Don't Change Anything, and Just Hit the Button!!!!!!!!!!