How do you feel about using CNC?

[kvom]

I am curious to know if classrooms teaching young people today to be professional machinists teach them to do manual machining first before they teach them the computer machining technology and programming skills?

At my school they start with measurement skills, then drill press and tapping, then lathe and manual mill, before CNC. The manual lathe skills include taper turning, single-point threading, and knurling, in addition to the turning, facing, drilling, boring common activities.

For CNC lathe, the g-code is all manually programmed in order to teach the canned cycles. CNC mill starts with manual programming, adding tool radius offsets, and finally MasterCam at the end.

The people in the automotive sports (race mechanics) program also take several classes in manual machining.

 

[bearcar1]

I would love to have CNC capability in my shop but the dollar factor has squashed that idea to the point that it will most likely never happen. Shoot, there are times that the manual world gets me down, I can't imagine what all the programming involved in the production of a part would do to my fragile mental state. From a basic standpoint of "program it, set up the blank, push the start button and relax(?)" I think it would be a lot of fun all around. On the other hand, a well thought out and executed series of steps using fixtures and jigs on a manual machine brings just as much enjoyment. Is CNC 'cheating'? I guess it would depend on the definition of what it is supposed to be 'cheating' on. It still requires one to have a knowledge of the basic part being made and how to produce that part on a CNC machine, just like similar knowledge is required for operations on a manual machine, so 'cheating' I think is a relative term. As for consistent speed and repeatable accuracy goes, CNC would be the way to go in most instances involving complex shapes. Still, I'll just be happy with my "old-fashioned" methods of parts production.

BC1
Jim

 

[spuddevans]

I am in the process of converting my X2 mini-mill to CNC, but before deciding to convert I had seriously considered getting glass scale DRO's for all axis', but then I realised that the cost would go quite a long way towards converting to CNC.

That was when I decided to go down the CNC conversion route, not especially to make all complicated, amazing CNC-made parts, but more to use it in a more manual mode of operation with the advantage of having DRO-like displays, the ability to type in the distance and speed you want to move, and also to make use of the many "Wizards" that Mach3 has which are very handy.

I havent got into the whole CAD/CAM aspect yet, I am still learning how to use it manually 1st, and getting to know the "feel" of the machine. Maybe in time I will expand into this area a bit more.


In short, I think CNC has its place, it is not inherently better than manual, nor inherently worse, just different ways to achieve a desired objective. Each have their own advantages and disadvantages, If I had the room ( and the money ) I would have one of each.


Tim

 

[Maryak]

I have just achieved a basic understanding of 3D CAD. I have already come to appreciate its' value as a tool over 2D drawing manually or CAD.

I know nothing about CNC but it seems to be the way of the future and has a skill set all of it's own.

To a greater than you may think degree, everybody here uses a large chunk of modern technology by being on the internet and using our forum as a means of sharing our common interest.

Those who use CNC are at least one step ahead of me in their acceptance of new technology and in the way they decide to spend their hobby dollar.

Have fun, enjoy and above all remember it's a hobby done for pleasure so please respect how each of us achieves our pleasurable end goal.

Best Regards
Bob

 

[wareagle]

For what it is worth, my $.02 worth: Have fun! At the end of the day, that is really what it is all about. Whether that is twisting dials, or programming G-code, it is still a hobby. The end result of our fun is an engine or two (or other cool object), a few tools tools and some new found knowledge. It sure beats the heck out of a lot of other activities that have nothing to show for it at the end other than a memory.


All of my stuff is done "old school". No DRO, no CNC. Digital calipers is as close to modern as my shop is in the tooling department. I do use 3D CAD, and find myself "cheating" with it at times when it comes to figuring machining sequences. Would that be considered tooling? Probably another topic right there!

But would I entertain a DRO or CNC machine? Absolutely! Would love to have a DRO on both the mill and lathe, as well as have another pair set up with CNC. The hurdle is funds. One day, we'll get there. But for now, I am perfectly content on using the dials to to transform scrap metal into parts scrap metal. ;D

For me, I admire the "old generation" of machinists (not necessarily the age of the guys, but the methods themselves). Especially those who cranked out countless parts using manual equipment. Some of these folks are nothing short of artists that turn out masterpieces with ease, and many are here at HMEM helping us "hacks" (me being the biggest!) improve our skills.

But, I also admire the computer machinist. It is truly a different mindset than a manual machinist, but in my eyes doesn't make them better. Just different. The "techy machinist" turns their dials with a keyboard and mouse. Once they have built their part electronically, they then send it to the robot (the CNC machine) and let the chips start flying.

When the dust settles, both the manual and techy machinist has achieved their desired goal by utilizing different approaches and skillsets. It is still a part sitting on the machine! Or in my case, likely a smaller piece of scrap! :big:

Going back to my first thought... It is supposed to be fun! Right?

 

[cl350rr]

for me it all comes down to available time and cost. I would love to dabble in CNC in my shop but I can afford alot of material and even some tool upgrades for the cost of setting one of my machines up for CNC. a great deal of my machining time is taken up restoring old or making new tools. I also do not have the time to complete the current projects on my list (the list has grown significantly since I signed up on this forum), let alone take on learning how to set the machine up properly to listen to a computer. for now I am content to work the machines manually, someday... who knows ;D

Randel

 

[Blogwitch]

I was, up to about a year ago, going to install a CNC machine in my shop, purely on the basis to help me with production work. Unfortunately, personal matters have meant I can no longer carry out any production requests, and the idea was permanently shelved.



Now back to the question, do you think CNC is wrong for making little engines.

You must remember, my comments are my own personal views, so no comebacks or arguments.

Yes, I do think it is incorrect.
But that is due to maybe my old fashioned views. In fact, as soon as I see CNC mentioned in any post, that post is earmarked not to be read again. I just can't be bothered with getting involved with anything I truly don't fully understand and don't like to see, and yes I do think it is cheating, but again that is my personal view. But at least I don't have to read every post now, like I used to do.

I come here to help people who have a manual bent on things, not people who do everything electronically. So as such, I am finding that manual machining is starting to take a back seat to CNC, which I consider a truly bad thing.

To my way of thinking, you should be FULLY conversant with manual machining first, then progress onto CNC. Purely because, when it boils down to it, and the cards are on the table and big bucks are at stake, I could most probably knock out or repair a part and get whatever is required running again while the CNC people are still punching the keyboard.

That is where manual machining scores, everything is up front and personal, you are making the decisions as it is happening.

CNC is absolutely great in my view, but in the right place, the production environment or specialised services that produce items that are literally impossible to do or not cost effective to do by manual machining.

I am sorry, call me old fashioned and out of date, but to my way of thinking, not for making little engines.

But of course, what would the world be like if we all thought and did the same thing. Problem coming on, I see a hint of CNC coming into that last equation.


Bogs

 

[Ed T]

I have some old metalworking texts describing in detail how to make a piece of metal thinner using a hammer and chisel. I suppose those familiar with that technique felt that the first milling machine was inferior because it didn't involve the same effort. The first clock parts were cut and filed from sheet by hand and by eye. It took a long time to make a fairly good watch. More modern processes made these kind of activities unneccessary and unaffordable. The progression from pure manual, to manual machines, to automated machines and, soon, to additive rather than subtractive processes is a natural one and, generally, leads to better, more consistent, less costly parts. OMHO a CNC part is not a bad or unwholesome part; it's just made a different way with a different kind of effort. There's still plenty of room for those, like myself, who make parts on manual machines or without the aid of a machine at all. I have several small CNC machines, but it has not been worth my time to figure out how to make them work. The technology that I choose is adequate to my needs. In years of dealing with commercial machine shops, I can fully appreciate that, for most jobs, CNC is the only commercially viable way to go especially for multiple parts. Since most of us are in a hobby where we are competing with ourselves, the answer is that you should do what makes you feel best about the process and and not worry about how someone else feels about your process.

 

[Tin Falcon]

As far as teaching methods some colleges are using the art to part concept.
Article here:http://www.immerse2learn.com/docs/Immerse2Learn_LCC.pdf?rdm=71285895
The students start out drawing a part on the computer then machine on cnc . then they learn the nuts and bolts and whys and why knots.
I am all for learning the old ways like laying out sawing filing etc and learning on the bench .but It is not the only way to learn or complete a task.
Tin

 

[NickG]

I guess it's horses for courses. It's fine using CNC for making model engines, but then the question I would have is, what is the person really into? Is his/her hobby computing, or model engineering? Could be a mixture of both I guess.

As somebody pointed out, it's not easy to create 3D models in the first place (well, actually that's the easiest part) but then you have to (if you want it driven from a CAD CAM model) think about tool paths etc and program all of those in. Most things that apply to manual machining surely must apply too, if you don't have the correct tool, speed, work holding etc it's not going to work. You'd still need to machine features in the correct sequence otherwise it wouldn't work. It's not like that 5 axis thing at hobby level - they cost a few hundred grand a piece so more than most peoples houses! Sometimes at hobby level, the only thing being done for you is where to stop and start cutting, no edge finding etc once it's got its initial datum. I know somebody made a flippant comment about DRO's but true enough they have some CNC traits. Backlash is no longer bothered about, they can memorise where you started have things like PCD features which tell you where to move to, the only thing it's not doing is moving for you. Of course, CNC can move more than one axis at once at predetermined speeds, hence being able to create complex shapes which we couldn't do manually without a great deal of effort.

I must admit I do prefer viewing topics where engines have been made on manual machines, when you look at work by the likes of Gbritnell you can see the effort he has put in to make complex radii blend perfectly to look like the real thing - a labour of love. With a good enough CNC machine, some of that could be done in seconds - that's not to say though, that a lot of work would be required to get the machine to do it successfully.

Also as other people have said - components might look perfect from CNCs but be assured they often aren't! It's a bit ironic, but some of the shapes created are that complex these days that you have to use CNC machines called coordinate measuring machines to check whether your CNC machines are making the bits correctly, and as I said, they often aren't.

 

[Lew Hartswick]

That is a good way to get rid of all the "Nay-sayers" at least. I'm sure all of us will not
be reading this group.
...lew...

 

[Kmot]

Boy did I blow it this morning when I typed my first reply this morning before I had enough coffee!!! :wall:

I meant to say: I have no doubt manually machined parts WERE PERFECT during WWII by machinists who made aircraft engines, for example.

 

[mocaquita]

Manual machining and CNC machining requires 2 different skill sets, and they also have overlapping skill areas. In a shop making one and two-sey parts (not mass production) they both have their place. Some things are faster/ easier on a manual and some are faster/easier on a CNC. The thing you have to realise is that for most of what you make (2.5D parts), a 2 axis CNC mill is very efficient. You have to be there to run the Z axis, but for one thing, a simplified conversational or CAM program is required. For conversational, no CAD drawing needed. Anyone exposed to using a Accurite 2 axis control on a Bridgeport class mill in an industrial shop knows exactly what I am talking about. A 2 axis in a home shop is great and the best thing is that it's cheaper!

Dave

 

[bentprop]

On a personal level,if I was (much)younger,I would probably take the time to learn cad/cam and cnc.
But at my age,I enjoy twiddling the handles on my machines,rather than punching keys on the key board.I learn by doing,rather than thinking.
I don't see cnc as "cheating",It's simply the modern way of doings things,sometimes faster,but not necessarily cheaper!
And,as someone else mentioned,DRO's are computer related items,are they not?And I'm quite happy to make use of them.

 

[Tin Falcon]

Lets not forget there are many levels of cnc machines as well. from small hobby educational units to machining centers that take a 20 foot piece of stock and turn it into a bin of parts everything automatic , tool changers bar puller parts catcher chip convener etc. the only human intervention is an occasional QC of a part and a wear offset adjustment of the tool(s) if needed. Of course a human has to set up and program the thing as well as do maintenance and repairs.
I know apples and oranges but there are macs red delicious granny smith etc navals .... Tin

 

[shred]

I have a CNC machine and a manual machine. Overall, one is no easier to make parts on start-to-finish than the other (and anybody that thinks you just push a button and out come perfect parts has only seen machine 'operators' running well-debugged programs on production machines). Different skill sets are needed and each is best for doing their own thing, but that's always the way it is.

I get more satisfaction making parts manually, but at the end of the day I'm about making stuff. The end justifies the means, you could say.

Other people can and do think otherwise. I suspect that's the way it's going to be pretty much until the end of time.

 

[milotrain]

I learned 3D cad before I learned any manual machining processes. However I learned the beginnings of manual machining before ever playing around with CAM software. Interestingly this corrilates well with the Hand Drafting vs CAD drafting debate that raged silently at my school where they still teach the first two years of design by hand drafting and not CAD drafting.

Because of this I still hand draw, and I still CAD draft, and of course as others have stated about CNC machines, they both have their place. I often sketch out ideas and layouts by hand as it's faster for me to get an idea of the work, but then I go immediately over to CAD when I need to reference exact sizes and locations in 3D space.

Most of the people on this forum don't do this for a living, this is a hobby, so that's why I think manual machining will always be popular with this kind of group. A great friend of mine who I went to school with and is a very good artist keeps a physical account book. She doesn't use quicken, even though everyone we know does. She keeps this book because depending on her hand writing at a given time she can tell what she was feeling, she doesn't have to note every little thought that goes along with a bill or a payment she can just look at the writing and know where her mind was. Indeed isn't that why we make things with our hands; so that we can see ourselves and our lives, in the work and get through the problems, frustrations, and joys of the day.

Andrew Carnegie was famous for saying "My heart is in the work." With the craftsman it truly is.

 

[mzetati]

uninterested. <G>
Why should I let a computer take my part of the fun?

Marcello
(who's been feeding puters for about thirty years, now)

 

[jpeter]

CNC open a whole new world to the home shop machinist. Its just another step up. It starts when you get your first mill. From there you hope to be able to get a more rigid, bigger mill. You can stop there but most long for a DRO. Getting that some wish for some form of mill with conversational programming capabilities... It never ends. I think its in the nature of us makers of metal things.

 

[GWRdriver]

Why should I let a computer take my part of the fun? - Marcello

I agree completely!