Thread: CNC machines and why i dont care for them

I love CNC machines. I'm soooooo glad my colleague down the street has some . And, he's pretty glad that I have some manual machines that can knock out a few things that he doesn't have enough travel for, or doesn't want to deal with GFO chips, etc. He has no interest in bringing in manual machines, so I fill a niche for him. OTOH, he gets work from me that I don't care to do, like the 20 holes drilled and tapped in 40 pieces, etc.

I'll bring in my own CNC machines when my volumes make it economically feasible. I'm not there yet .

Regards.

Mike

I work in a tool and die shop, with guys that have been making tools for 40+ years. The things they do with manual equipment are amazing. I run the CNC shop, we also do production machining. I model parts, dies and design fixtures, program jobs with a cam and long hand, setup jobs, run jobs, inspect parts, repair machines, and weld MIG and TIG along with customer relations and tooling and material purchasing. I pretty much do it all and I am constantly humbled by how much I don't know. When I was 25 I was too dumb to know how much I didn't know. I suspect you may be experiencing the same stage.

Looking at the parts the OP displayed as his accomplishments shows some time spent in front of manual equipment. That's great, you have some level of proficiency. The fact is for all but the most basic lathe and mill work a CNC is faster, and more accurate. Holding +/- .002 for one part isn't all that impressive. Build a tight clearance die or mold that has to hold .001 total circular clearance including both diameter and positional error, on two dozen features and then repeat that perfect alignment on several pieces and layers of D2 and 4140HT that are all machined separately. That is tougher, but I'm sure there are guys on here that work in the .0001's all day. Tooling work is all prototype work, you only ever make one of everything for a tool, mold or fixture.

If you think for one second that it doesn't take every bit of knowledge, skill and craftsmanship to do difficult CNC work that it takes to do difficult manual work your head is up your ass. When you finally hit the button on a CNC your thinking had better be done, and be correct. Any idiot can load a part and push the button in production, but someone has to know proper setup, fixturing, tooling selection, speeds and feeds and programming. If you can do complicated parts faster manually, it just means you suck with all the "easy" stuff that it takes to make CNC's work. Apparently the year at vocational school wasn't enough.

If manual was the way to go, why would those of us that worry about paying the bills spend so much money on CNCs? Manual still has a place, we do it everyday, but CNC's keep the lights on and the role of manual machining in mainstream business will continue to shrink.

Originally Posted by RDR

10,000 hours eh, well we all bow to your experience. 3.5 years stood in front of a bridgeport or lathe, i and most on here did more than that in their apprenteship and still knew nothing at the end of it. Wait untill you have 35+ years of experience before you come out with these sort of comments, then you might get listened to.

Theres 2000 hours in a work year. 40X50=2000. you had a five year long apprenticeship? I wasnt bragging i was responding to those who questioned my manual machining ability. and have said about three times now that i know how do a lot but am not an expert by any strech. Did they teach you reading comprehension somewhere in those five years? i also like how not one of you has said a thing about the real reason i wrote this thread, which i have brought up twice. The number of trained manual machinist is declining sharply. I bet the mean age on this forum is around 60

Originally Posted by pende

The number of trained manual machinist is declining sharply. I bet the mean age on this forum is around 60

Hey Einstein, there is only one reason the number of manual machinists is declining. They are not needed.

The amount a skilled workers will expand and contract to fill the positions available for them.

Do you recall the tale of John Henry? He worked himself to death racing against a steam hammer.

I run all manual machines in my shop. I wish to god I had a cnc mill or lathe, you should stand in front of an old W&S turret lathe for a couple of weeks cranking parts, it is brutal. Someday I will buy a cnc mill hopefully next year, if you want to see my shop check out my youtube video The last Stake maker. Dont pay any attention to the antique cnc mill in the background it doesnt work and is now a manual mill. I do production on manual machines, I run shapers horizontal mills and turret lathes.

Originally Posted by pende

I bet the mean age on this forum is around 60

I wouldn't bet on it. I'm 31 and I know there are many my age or younger on here.

"On top of that if your doing one-offs many parts can be done quicker manually than even using conversationial programing."

Ummm,I dunno about that.In some cases this may true but with the ease of setup and programing of todays CNC you may be making chips while I am setting up,but like a top fuel dragster when you get close to the finish line here comes the CNC to smoke your ass.

We are a job shop,20 parts is a hudge run for us.I mostly make pump shafts and replacment parts for fluid pumps of all sizes and shapes.Today at 4:45 I started on a rush job due in the AM,I bored my jaws,faced and center drilled 2.500" 4140 stock,programed five fits just useing a calculater and GCode on the first end with the smallest diameter 1.250".I roughed 18.750'' of a 20'' shaft to .020'' over finish and closed the shop at 5:30.I'll have the other end programmed and roughed in by 7AM tommorow.

I am no slow poke on a manual but speaking for myself,I would be hard pressed to machine the radiused corners and hold 5 shoulder lenghts to .002" in 45 minutes.If nothing else,at 2500 RPM all my coolant would be on the floor with a manual

If shaft work for ones and twos were not so much faster on a CNC we wouldn't have another 95K machine due in the shop on the 15th of this month.

Here is another scenario where CNC wins.

Let's say you have a one-off part. It takes 2 hours to bang out on the manual Bridgeport or whatever. It also takes 2 hours to program and run on CNC. No complex features.

Now let's say you fuck up. It happens. Part is scrap from a simple mistake.

Now you have to make another. It takes 2 more hours to bang one out on a manual. The guy on the CNC make a quick edit and has a part in 10 minutes.

Seems like the CNC is the winner here.

There are some really good points made already.

Pende, three out of the four parts you posted pictures of could be made with a file and a drill press, but would you? I wouldn't, but then I was born after milling machines were invented. There was a time when most metal tradesmen would have had the skills to make those parts without a mill, some still could now but very few. Is this a tragedy? No, industry has enough great filers, the rest of us use machines, supply and demand. Yes there are less manual machinists around now, but as fun as manual machining is (I prefer enjoy manual machining but have a CNC and use it frequently), moden technology and a competitive industry requires most machinists use cnc.

Ha, ha, I have to go and do some filing on an injection mould now, the irony....

i Apologize. I am foolish, inexperienced, and short sighted.

Yes, yes you are......haha..but on the bright side, now you know The real bright side is that we have all been "that guy". It's part of the process and the older you get the easier it is to see.

You started this thread with the intention of stirring the pot, and you succeeded. Get back in the shop and keep learning, honestly you're doing pretty well for 25. Most of your contemporaries are still living at home in mama's basement and playing Diablo III until 3 am.

Whatever you do...keep learning, manual or CNC, 3d CAD/CAM or welding, keep learning.

It never ceases to amaze me that people think you cant use a CNC like a manual. The issue is Programming time? MDI Mode. End of argument. Mounting a tool in a holder is on par with swapping one in a drawbar in most cases. We do a touch of production, but is mostly prototype work.

I get that manual machining can be more fulfilling, and I personally enjoy it when I get to do it. But to say there is no craftsmanship in CNC is ridiculous.
You crank a physical handle, while I crank a digital one. The tool still does what its told, no matter the form of the input device. CNC vs Manual, you just learn to read how the tool is via different (usually less) feedback.

I dont have all THAT many more years than you Pende, but dont discount the opinions these guys are throwing out there. Old age and treachery is usually more effective than youth and ambition. My pride has the scars to prove it.

I understand where the OP is coming from. I am 30, been machining since I was 16. Had my first shop at 19. I have never owned CNC, but have run them. I personally do not like them, but they are definetely needed. And yes, there are a lot of button pushers out there who have no idea about how to setup or run the machines. But the best CNC guys I know were great manual machinists.

In my line of work, CNC will never have a place here. I do large parts of low volume. I have taken these jobs away from CNC shops because I can do them in about half the time. But I also push my machines beyond their limits. I know what they are capable of. Sure CNC would be great if large capacities were more affordable. But as it is, my parts are large enough I usually run 3 different machines at the same time. I may be turning a long pass on the lathe, running a bore or facing on the HBM and drilling or welding something all at the same time. If I werent into large parts, I probably would only have 1 manual lathe and mill and the rest CNCs.

Untill you have owned your own shop and see what it really takes to stay alive, you should not be so opinionated. You have some experience, but nothing that I would consider to be enough to make these judgements.

I did say I also hate CNC, but if I were in a different line of work, I would definetly have them.

Josh

Originally Posted by ADFToolmaker

three out of the four parts you posted pictures of could be made with a file and a drill press, but would you?

That's how my training started out. We laid out about a 4X4 plate of 1/2" thick cold rolled. Drilled about 11 holes, had to tap 4 by hand, had to C'bore 4 after grinding a flat bottom drill, and then cut a triangle out from the other 3 holes. The sides of the triangle had to be filed so that the edges were tangent to the holes, straight, and square with the top and bottom. I think that we had 10 or 12 hours to make that part. That one part cut the class from 12 to 6.

I made 2 gear blank dies for a winch company. We used a hob to make the punches and then laid out the die section. All the teeth (lots of them) were roughed on a band saw and then fit with a die filer. IIRC, about 2 months for each die.

Now, I learned a lot from these projects, but no way would you do that stuff except for a learning process today. There are fewer and fewer skilled metal workers. Why??? Very few want to get into it. Most of the high school programs are gone. Even a lot of the trade schools have trouble filling their classes. Don't blame CNCs the problems are much deeper. You probably should visit some foreign countries and see how their education systems work.
JR

I think I get where you're coming from.

I've been a machinist for several years and have used CNC and Manual machines (started on a 1941 Marnarch lathe that had a full rotation of free play in the cross slide! And I can still hear the clutch cling and clang when I lay in bed at night, but that's another story).

I sometimes imagin myself in a poorly lit room surrounded by old machines and cranking out beautiful parts. Like some sort of high tech blacksmith or something. But the reallity is that my shop is extremely well lit, with 3 Haas machines a tig welder and other than a drill press and a grinding wheel, nothing manual in sight. When I have to make unusual or one off parts on my Haas I approach it in much the same way I did as a manual machinist. The only real difference I think is that I actually do all the math and finish the part in my head and on the computer before I put any metal in the machine
.
I took some welding classes at the local communty college recently. And it struck me that as "cool" as Tig welding is, I still prefer the O/A kit. I don't know why exactly. I think it's just the history of it all. I believe the same can be said about Manual v. CNC machining. History is cool.

I still dont care for them. Craftsmanship was the wrong word. Soul. Theres no soul in a CNC. An HLV'S or a 10EE thats a piece of art in my mind. I look at them and imagine all the blood sweat and tears that when into building and using them. All the four letter words spoken over them by someone who grabbed the wrong handle. A Mori Seiki NXL2500. That's a machine. Given a necessary machine with wonderful capabilities, but still just a machine. One is a Cuda with a sixpack the other is a ZR1 Vette. Sure the Vette is better in pretty much every way, but it has no soul, and is nowhere near as cool.

There have been plenty of 4 letter words spoken by people who pushed the wrong button.

An HLV or 10EE is an antique, like a horse drawn plow

Tons of blood, sweat, tears, and four letter words have dripped on CNC equipment too. Mistakes in code, wrong handles...its the same thing. What you are describing happens on both sides of the fence.

See last post one more time. I added some

Originally Posted by pende

One is a Cuda with a sixpack the other is a ZR1 Vette. Sure the Vette is better in pretty much every way, but it has no soul, and is nowhere near as cool.

I believe that is called an opinion.

I personally would not walk across the street for a "Cuda". Unless it was parked next to a hard top 356 Porsche. There is a car with soul...