CNC or manual machining? (1 Viewer)

[e9999]

Want to talk a bit about how they compare?

Like what is better to start with if you have not done any machining before?

Or is it worthwhile contemplating learning about CNC if you already know manual machining? And v-v.

Or under what conditions is one of the 2 faster ? (since that was tentatively discussed elsewhere)

Let's keep this positive and constructive, of course.

 

[e9999]

On sort of a hybrid question, one issue I've been wondering about is how easy it is to do manual machining with a typical CNC machine. As in, without any software programming. IOW, can you move the tool forward so many thous with a knob or a joystick on the main console, kinda like you would by spinning a crank handle on a Bridgeport to move the table? Could a proficient "manual" machinist use a CNC machine without knowing anything about the programming side, just by using the hand controls -if any-? Is that realistic?

 

[PIP]

On sort of a hybrid question, one issue I've been wondering about is how easy it is to do manual machining with a typical CNC machine. As in, without any software programming. IOW, can you move the tool forward so many thous with a knob or a joystick on the main console, kinda like you would by spinning a crank handle on a Bridgeport to move the table? So, could a proficient "manual" machinist use a CNC machine without knowing anything about the programming side, just by using the hand controls? Is that realistic?

Cnc lathes and mills have a pulse generator handwheel to move axis in selectable increments, usually. 01", .001" and .0001" per click. They also have jog mode with selectable feedrate.

You can use the handwheel and jog to do basic machining. Like face a part or mill a straight line. Drilling takes extra care.

There's no feedback like a manual machine will give you. It's a lot different, but manual mode can be used to do a lot of things if you need to.

Manual mode is primarily used for making setups. For indicating in fixtures, vises and reverse engineering things.

 

[DangerNoodle]

If you've never run anything before, a CNC is a lot to get ahold of. You can run it like a manual mill, but it's really easy to mess stuff up with no feedback.

Programing is a whole animal within itself, and it is not a super easy thing to pick up without a lot of mistakes or a good teacher. It's really easy to crash something without a lot of practice or a simple overlook on something. I'm not great at either, but I'd much rather run a manual machine for simple parts and get help programming and running a CNC.

 

[e9999]

Say I know how to use a Bridgeport but I don't know how to program a CNC yet, and the CNC is the only machine I have access to to make a simple part I need, like a 1-2-3 block. How many hours of learning / practice before I can make one in "manual" (not programming) mode on the CNC mill, you think? Are we talking 10 hours or 100?

 

[PIP]

I learned manual basics in high school shop class. I learned machining for a living with CNC.

As time passed I added a few manual machines as opportunities came up. I use two manual lathes that share tooling. I keep the shorter one setup with a 3 jaw and the long one with a 4 jaw. This covers 99% of the work I do with them. I also use a 4" Horizontal Boring Mill and a Bridgeport.

I use the manual machines almost exclusively for repair work to support loggers and farmers. I need the capacity of the large manual machines i have for the work i do. CNC HBM's and lathes with 10ft between centers are too costly to justify for the work i do. I would happily replace most manuals with cnc if it wasn't a huge expense. I would keep my short manual lathe. That would be hard to live without for quick jobs. But milling- No need for manual at all for me.

I use two VMC's with 4th's and an HMC for all my cnc milling. I use three lathes to cover all the different parts i make. One small 1-5/8" capacity collet nose Hardinge with a barfeeder and live tools. A simple 2 axis Doosan Puma with a 10" chuck and 3" bar capacity. A big Leadwell with a 16" chuck, 5" bar capacity and live tooling.

I try to implement strategies for fast changeovers/efficiency.

To me, machining is all about figuring out how to hold onto the material/part and the machining strategy. Manual and CNC processes arent in competition. A good manual machinist should make an awesome CNC guy if he can unlearn some limitations manual machines have. A good CNC guy shouldn't have any problem using a manual machine effectively once they figure out what the levers do. However, there are a lot of nuances and tricks to making good parts fast with manual machines.

The guys i know that could make good parts fast using a Bridgeport are in thier mid 80's now. Not a lot of ways you can learn that stuff today and besides, theres no reason to.

Another thing to consider if we're talking manual vs cnc is even a really good old school manual machinist can't do much better than +/- .002" with a Bridgeport. A decent quality cnc mill is pretty easy to cut that in half. With some care you can do 10 times better. The surface finishes and tool life with cnc are so much better.

Another big one is that manual machines peaked in the 1950's and 60's. Every machine tool builder put 100% of thier focus into CNC by the mid 70's. You take the beefiest, finest made American manual lathe made from Monarch, Lodge&Shipley, American, Axelson, etc from the 60's and compare the build quality to a Japanese CNC like Mori or Okuma from the 1980's and there is no comparison. Sure, the old manuals were mechanical marvels, but the higher end CNC's were built even better. So you get this baked in superior quality with cnc not found in manual machines.

 

[PIP]

Say I know how to use a Bridgeport but I don't know how to program a CNC yet, and the CNC is the only machine I have access to to make a simple part I need, like a 1-2-3 block. How many hours of learning / practice before I can make one in "manual" (not programming) mode on the CNC mill, you think? Are we talking 10 hours or 100?

Using a cnc in manual mode is dirt simple. If you have no familiarity with cnc controls at all you should get someone who knows it well to give you the basic rundown.

 

[e9999]

I'm thinking one difference is that in the old days, somebody with relatively little formal education but a good head could learn how to be a proficient machinist on the manual machines, and make a good living. But now having to learn full CNC is a higher level activity, you need to know computers, CAD, programming etc, so the upfront hurdle seems much higher and may limit access to the field more. Is that true?

I was struck by both of you mentioning the lack of tactile feedback in manual CNC mode. That is a very good point. We do take that for granted with the manual machines.

 

[PIP]

I'm thinking one difference is that in the old days, somebody with relatively little formal education but a good head could learn how to be a proficient machinist on the manual machines, and make a good living. But now having to learn full CNC is a higher level activity, you need to know computers, CAD, programming etc, so the upfront hurdle seems much higher and may limit access to the field more. Is that true?

I was struck by both of you mentioning the lack of tactile feedback in manual CNC mode. That is a very good point. We do take that for granted with the manual machines.

Once you get the basics cnc is easy. And manual machining is not so easy. You have a ton of stuff to keep track of in your head. Manual machines don't have safety systems or enclosures.

My personal belief is that machining is very well suited to people with strong spacial reasoning and a bit of patience. People with dyslexia and ADHD often excel at this stuff because theyre wired for it.

I help out/mentor a real go getter 16 Y/O kid in my shop. He has product ideas and wants to do all the things lol. He taught himself F360 modeling in a week by watching youtube tutorials. I got him up to speed on Mastercam over a couple Saturdays. I let him Program, setup and run my Kitamura 5X that's worth as much as my house.

I believe just about anyone can do this stuff if you have the tenacity to dive in and figure it out.

 

[PIP]

I remember when I bought my first CNC lathe, a 1979 Mazak with a Fanuc 5T control. The guy I bought it from came to my shop to show me how to use it and I watched his fingers hammering code into the control at lightening speed. I thought that was insane, no way any normal person could do that. A few eyars later I caught myself doing the same thing and realized it wasn't that big of a deal.

I met a shop owner in my small town that blew me away though. The guy was like Rainman- Genius with numbers. ASD for sure. He had 4 verticals and two HMC's running complex aerospace gearbox housings in 7075 and Ti. He did not have any CAM software. He literally did it all in his head and keyed programs into the controls. It was insane. He also used white powders to stay up all night making parts to get money to buy more white powders and that didn't work out great for him in the end. Fascinated me that anyone could do that level of 4 axis milling code in their head.

 

[mattressking]

It's like asking what is better - fuel injection or carburetor?

Both have their benefits and pitfalls, pick the one you resonate with and move forward. In the current job market - CNC/programming is the way to go, especially if you tune in AI to assist in loading and improving machining efficiency.

Manual machining is for the cool guys and engine work, it is also neat as hobby but unfortunately it is a dying art. If you want to be one of the folks that has the skills to continue it, then start with buying a Bridgeport or similar and get to work.

 

[e9999]

are manual machines still used much to teach basic machining in schools, votech, community colleges and the like, you think? I know that at a local high school they bought a bunch of manual machines for a tech program not too long ago, but at a nearby university they have gotten rid of just about all of their manual machines and are now using only CNC to get engineering students started in the machine shop.

 

[PAToyota]

I tend to feel that starting with a manual machine gives you a more solid background than jumping right into CNC. As mentioned, you just don't get any "feel" using a CNC machine. Personally, I think there is a difference between someone who understands manual machining - even if they're currently only doing CNC work - and someone who just "punches the buttons."

And, as mentioned here or the other thread, there are simple things that could be quicker on a manual machine rather than programming everything in to do it on CNC. The flip side to that is that when you're working with CNC you can easily do more complex things and your simple part takes on a life of it's own.

Case in point, a "simple" spacer - it could have been hidden under the gas cap and roughed out with a sander to fit the contour of the hood well enough, but it quickly went to being a "showpiece" item:

I know I'd have a hard time doing the machine work by hand and forget about turning out two identical parts by hand.

 

[GeoRoss]

are manual machines still used much to teach basic machining in schools, votech, community colleges and the like, you think? I know that at a local high school they bought a bunch of manual machines for a tech program not too long ago, but at a nearby university they have gotten rid of just about all of their manual machines and are now using only CNC to get engineering students started in the machine shop.

Not really where I work. We do have them and the students use them for a week or two (lathe and mill) to get their feet wet, learn what everything is and does. But we get them training on the CNC as soon as possible because that is what the workforce in my area uses and want trained people who can do it.

 

[PAToyota]

And, as mentioned here or the other thread, there are simple things that could be quicker on a manual machine rather than programming everything in to do it on CNC. The flip side to that is that when you're working with CNC you can easily do more complex things and your simple part takes on a life of it's own.

Another example. A switch panel with beveled edge and holes would have been easy to turn out on a manual machine - but, gee, let's label the switches while we're at it.

 

[PIP]

A few years ago I hired a younger guy that knew manual machining well. He was pretty good at running all the manual machines. He said he wanted to learn CAM and CNC, but I found he just didn't want to put in the time to learn so he never did and in the end he just wasn't a good fit.

He had it in his head that most things he needed to do were faster to just use a manual machine, but it almost never was.

The anti-cnc mindset is kinda toxic to productivity.

 

[e9999]

^^ looking at those big labels, I was thinking "Wow, neat!"
But then on further closer examination... I thought "WOW, WOW, WOW!"

 

[PAToyota]

He had it in his head that most things he needed to do were faster to just use a manual machine, but it almost never was.

The anti-cnc mindset is kinda toxic to productivity.

If you're just turning something down for a better fit, drilling and tapping some holes, or cutting or beveling straight edges manual is likely faster.

But add in some curves, compound curves, text, or making multiples and the benefits of CNC add up quickly.

Even for a one-off piece, you may need to make multiples with tweaks to get things right. With CNC you can make those changes and turn out another iteration quickly without worrying about the rest of the item since all of that is already programmed in there.

You also need to be proficient with the software. If you're using it daily, you start learning shortcuts and best practices. If you're just going to it a few times a month you'll likely struggle a bit each time.

 

[PIP]

If you're just turning something down for a better fit, drilling and tapping some holes, or cutting or beveling straight edges manual is likely faster.

But add in some curves, compound curves, text, or making multiples and the benefits of CNC add up quickly.

Even for a one-off piece, you may need to make multiples with tweaks to get things right. With CNC you can make those changes and turn out another iteration quickly without worrying about the rest of the item since all of that is already programmed in there.

You also need to be proficient with the software. If you're using it daily, you start learning shortcuts and best practices. If you're just going to it a few times a month you'll likely struggle a bit each time.

It was a little different than that. Most of the parts were large hydraulic cylinder rods, pistons, clevises and barrels. Alot of the parts needed a large amount of material removal.

An eye or clevis end for a large hydraulic cylinder rod is a good example. In our big 50 taper vmc it would probably take 2-3 hrs to program, Setup and mill a large rod end from solid steel. On the 50 taper manual hbm it can easily take a whole day and you're working your butt off to do it.

Lathe parts like rods are similar. My big lathe can take a 5" shaft through the drawtube and it has more than enough grunt to cut right through induction hardened rod. It's 25k lbs and 80 hp. My biggest manual lathe is a 20x120" late square head Pacemaker with 15hp and 12k lbs. It would be significantly faster to run rods in my larger, faster, enclosed cnc lathe.

One big problem with trying to make parts fast on manual machines for emergency repairs is you make mistakes. We've welded up a lot of parts over the years that never would have that problem if they were done in cnc. Nothing fun about paying an employee $35/hr to make the same part twice lol.

Another big factor is while the cnc is munching away, nobody's chained to it. Other work is done at the same time. One guy can run 3+ cnc's at the same time.

 

[The Machinist]

are manual machines still used much to teach basic machining in schools, votech, community colleges and the like, you think? I know that at a local high school they bought a bunch of manual machines for a tech program not too long ago, but at a nearby university they have gotten rid of just about all of their manual machines and are now using only CNC to get engineering students started in the machine shop.

The classes I took at the county vocational school in my junior and senior years of high school started us out on manual machines and transitioned us to basic CNC towards the end, but in hindsight I would have been much better off early in my career if those early classes spent more time focusing on CNC basics. (this was around 2010) After high school I continued classes at a very nice community college with a very well run machining program that got a lot of support from the local industry and machine tool companies. That program only had one or two quarters of manual machining and the rest of the program was focused on GD&T basics, CNC programing, CAD work, etc. I got so much more out of those CNC courses than I ever could have learned from a basic manual machine focused program. Having an experienced programmer/machinist (who was teaching nights alongside his day job), teaching a programing course was invaluable; I may not have mastered Mastercam in those courses, but I did learn a hell of a lot about how to approach programming a job and how to accurately and reliably design fixturing.

Design & Manufacturing Technologies

A few years ago I hired a younger guy that knew manual machining well. He was pretty good at running all the manual machines. He said he wanted to learn CAM and CNC, but I found he just didn't want to put in the time to learn so he never did and in the end he just wasn't a good fit.

He had it in his head that most things he needed to do were faster to just use a manual machine, but it almost never was.

The anti-cnc mindset is kinda toxic to productivity.

In the last two years or so we have had a few guys come through the shop I work at that had some operator experience and were excited to learn more and said they wanted to learn to program, but also just didn't want to put the time in to learn it. We like to hire entry level and train up, so the owner was happy to hear that these guys were excited to learn. We got them setup with a computer in the shop with access to NX and had them start with modeling and programming simple stuff like softjaw blanks. All that we asked is that they practiced after hours. Out of three guys, none of them spent more than two hours total.
On a more positive note, we hired a long time friend of mine about 4 years ago and gave him the same opportunity. He got after it right away and went from almost zero machining experience to being the best setup guy in the shop, and is now a solid programmer knocking out aerospace parts every week. All because he was staying late every night playing around on the machines and learning CAD/CAM after hours.


Big take away for anyone looking to get into the machining industry: you are going to need to learn as much as you can on your own time. There is so much good training and information available online now, its easier than ever to get a good foundation of training. (just don't expect to get a programming job day one)