Similarities between CNC and manual

[RB211]

I simply didn't want to derail Brian's thread, so I started this one.
The little I've done with CNC in my home shop I feel I have enough experience to chat about it.
CNC is still machining, still requires knowledge and skill. It's a tool. Just as autopilot is a tool for pilots to hand off some of the work load. When I first started, I must of snapped 10 carbide endmills because I no longer had direct feel on the handwheels. It really drove home the need to know speeds and feeds, chip load per tooth, etc. However, once you learned those, you can save it to a file and apply them to the future.
CNC machining is the ability to precisely reuse what you learned previously.
The person doing this is a machinist. The guy that is far removed from the process and simply loads parts is a machine operator. In the home shop or one man shop, the machinist does both.
Manual machining can require involved jigs, CNC is no different. Manual, the emphasis is on producing the ability to do something, with CNC it's about work holding and referencing an accurate location.
A machine can turn handwheels far faster and more accurately than I can, so why not let it do it? It frees up my time to do more design work, or maybe prepare stock on a manual machine. It allows complex cutting paths without the use of jigs, it allows me to put contours on things to look nicer that I would of skipped on a manual machine because the effort was more costly than what it would gain for the part.
Manual machines really shine when you need to quickly remove some material on a part, fix something, etc. If you are designing something from the ground up and using 3D CAD in the design phase, it's very easy to slap on some CAM tool paths while you're at it. If you were going to manually machine the part, you'd spend just as much time producing 2D dimensioned drawings to use.
CNC is just another tool in the HSM toolbox with some amazing benefits.
The joy for me is holding the finished part and seeing what I designed on the computer exist in real life. It's appreciating the fit and finish, being validated on each machining operation. A lot of people say the fun is turning the handles, I feel it is a perfect analogy to being a jet pilot with flying by turning dials.

[DR]

I do all my machining on my CNC's. Recently I needed to make a set of keys for locating a milling vise to the mill table, 5/8" square bar to fit the vise base held in the vise so the top could be milled to 7/16" to fit mill table slots. . It was cold and rainy so I decided not to go the 50 feet to my backyard shop to use the CNC. Used a manual vertical mill in the basement. I started by using an edge finder to locate the both edges of the stock, did some calculations to determine how much needed be removed from each side of the blank. Tediously took the cuts measuring occasionally while cranking the dials. When the milling was done I used a file to round the sharp corners. Total, more than an hour. At reasonable shop rates $75 for a pair of keys.

After I was done I realized how spoiled I was by CNC. On the CNC I would have used the probe to locate the stock. Using a frame cycle in conversational I would have milled down to 7/16" with corner rounding. All told maybe ten minutes, loading a tool and programming. $15 or so.

I have years doing manual machining and I've come to hate it.

[RB211]

I do all my machining on my CNC's. Recently I needed to make a set of keys for locating a milling vise to the mill table, 5/8" square bar to fit the vise base held in the vise so the top could be milled to 7/16" to fit mill table slots. . It was cold and rainy so I decided not to go the 50 feet to my backyard shop to use the CNC. Used a manual vertical mill in the basement. I started by using an edge finder to locate the both edges of the stock, did some calculations to determine how much needed be removed from each side of the blank. Tediously took the cuts measuring occasionally while cranking the dials. When the milling was done I used a file to round the sharp corners. Total, more than an hour. At reasonable shop rates $75 for a pair of keys.

After I was done I realized how spoiled I was by CNC. On the CNC I would have used the probe to locate the stock. Using a frame cycle in conversational I would have milled down to 7/16" with corner rounding. All told maybe ten minutes, loading a tool and programming. $15 or so.

I have years doing of manual machining and I've come to hate it.

Only thing I do on my Bridgeport as of late is face mill. Just bought a face mill for the CNC.

[A.K. Boomer]

CNC is just another tool in the HSM toolbox with some amazing benefits.
The joy for me is holding the finished part and seeing what I designed on the computer exist in real life. It's appreciating the fit and finish, being validated on each machining operation. A lot of people say the fun is turning the handles, I feel it is a perfect analogy to being a jet pilot with flying by turning dials.

A purebred CNC machine with no manual input handles is like a stealth bomber pilot that needs constant computer assistance to fly, kinda like some parts can only be built by CNC,

but if the machine is equipped with both and the part can be made manually then one runs into choices of what mode they want to create the part in,,, so since your the Jet pilot that has both auto-pilot and manual what do you call more fun? I guess total menial tasks it's not about "fun" and just let the AP pick up the tab,,, but when skilled maneuvering is needed I bet you like to toss that pig around a little???

[RB211]

A purebred CNC machine with no manual input handles is like a stealth bomber pilot that needs constant computer assistance to fly, kinda like some parts can only be built by CNC,

but if the machine is equipped with both and the part can be made manually then one runs into choices of what mode they want to create the part in,,, so since your the Jet pilot that has both auto-pilot and manual what do you call more fun? I guess total menial tasks it's not about "fun" and just let the AP pick up the tab,,, but when skilled maneuvering is needed I bet you like to toss that pig around a little???

I don't get to do anything of the sort unless it's in the sim for recurrent. If it's in real life, it's a REALLY bad day.

[A.K. Boomer]

I don't get to do anything of the sort unless it's in the sim for recurrent. If it's in real life, it's a REALLY bad day.

Makes sense --- I sometimes forget about all the responsibility that's heaped upon you... I would crack under the pressure... I always try to thank the pilots when exiting the aircraft....

[olf20]

I'm not a machinists but I have (converted) a Bridgeport type mill to CNC.
I used Vetric software and have created lots of projects in both metal
and wood.
I agree that seeing something come to life from something you put into
a computer program is very satisfying. When I do a project I learn something
every time.
I'm very grateful to all the people on this site!! You have taught me LOTS!!
olf20 / Bob

[polaraligned]

Even the simplest tasks I go to my CNC Bridgeport. My manual BP collects dust in recent years. I can turn the MPG or do a quick G-code input for simple tasks like a quick facing cut, etc.

[RB211]

Even the simplest tasks I go to my CNC Bridgeport. My manual BP collects dust in recent years. I can turn the MPG or do a quick G-code input for simple tasks like a quick facing cut, etc.

Haven't used it yet but the Centroid controller on my mill has conversational programming

[BCRider]

I don't get to do anything of the sort unless it's in the sim for recurrent. If it's in real life, it's a REALLY bad day.

Oh come on, I'm sure the thought of doing something like replicating Tex Johnston's 707 barrel roll has tickled the back of your head at times. But the forebrain countermands those baser urges....

[A.K. Boomer]

Oh come on, I'm sure the thought of doing something like replicating Tex Johnston's 707 barrel roll has tickled the back of your head at times. But the forebrain countermands those baser urges....

I was wondering about having to go skeleton crew to shuttle aircrafts and if you had a willing crew then im sure it could be allot of fun - then I remembered that everything gets recorded so not worth getting canned i guess....

[Dan Dubeau]

The thought process to plan out a part is the exact same between manual and CNC. You have to know how to work through the proper steps in the proper order to achieve good results. CNC isn't the magic most people think it is. It doesn't magically just make good parts. You still have to tell it EXACTLY what to do, the same as you do your hands while spinning handles. It DOES allow for some fantastic options for metal removal that would otherwise be difficult or impossible with a manual. Things like helical interpolation for counterbores/holes etc. Trochoidal milling...amazing in certain situations. Conversational programming is wonderful too. Don't forget making a duplicate part, or other multiples, or mirror images. Being able to walk away and do another task while it's doing it's thing...If you truly put the time and effort into learning how to utilize CNC properly and all the benefits that come with it, you will never go back. It's just another tool and skillset to learn that unlocks amazing potential. Or it stacks up scrap much faster than you can by cranking handles. You get out what you put in there is no magic.

[RB211]

Oh come on, I'm sure the thought of doing something like replicating Tex Johnston's 707 barrel roll has tickled the back of your head at times. But the forebrain countermands those baser urges....

My thought process is really simple, "what do I need to do to continue to collect a pay check?"

For all the crazy thoughts, that's where my VR simulator cockpit comes into play with DCS World, VR, Force Feedback, and tactile transducers.

[RB211]

I was wondering about having to go skeleton crew to shuttle aircrafts and if you had a willing crew then im sure it could be allot of fun - then I remembered that everything gets recorded so not worth getting canned i guess....

Oh yes! The airplane records everything, and phones home. I believe I've frequently voiced the opinion that I'd retire tomorrow if I could.

[polaraligned]

Haven't used it yet but the Centroid controller on my mill has conversational programming

Yeah, I run Centroid too. If I need something more than very simple, I just use CAM instead of conversational, it only takes a few minutes longer and I know it will be right. I am not used to using the Centroid conversational and I would probably screw something up.