Time for a name change?

[Roger Provins 2Participant @rogerprovins2]

[Roger Provins 2Participant @rogerprovins2]

What's you view on the proliferation of computer controlled machinery into model or hobby engineering? When so much equipment can now be bought to eliminate hand skills might not a better name be computer numerical controlled model engineering – CNCME?

 

As Brian Abbott recently said in post about part of his project…

“Thanks both, unfortunately the only skill I applied to these was to program the machine and clamp them in the vice.”

Edited By Roger Provins 2 on 05/01/2016 10:27:53

[Geoff TheasbyParticipant @geofftheasby]

Where's the skill? I deliberately bought manually controlled lathe and mill, metric too, on the basis that, if I didn't understand how they worked, and how to use them, then I might as well pay someone else to make my projects. If you want to learn how CAD/CAM works, then fine, go CNC, but now I know that my inefficient, clumsy, hand-crafted projects are all my own work and I'm learning fast. I'll never make a good modeller, but I'm having great fun!

Geoff

[Ralph HParticipant @ralphh]

I cannot speak for the majority due to age but I have nothing CNC or similar, the most up to date being a Micro 2000 micrometer. The majority of my kit is Inches / English, very old or antique and making things manually using the "old ways" has always been my interest. I think the proliferation you speak of will have the ultimate effect, particularly if starting out with only skills in that area, of severely "de-skilling" things. This is certainly the way it has gone, as I have seen, in industry.

Catchy name though.

[David Clark 13Participant @davidclark13]

If you can't use manual machines you should not be using CNC as you won't be able to use them to their best ability. I used to know severel CNC millers who could not manual mill. Totally useless.

[Roderick JenkinsParticipant @roderickjenkins93242]

Roger,

Whilst I would love to add a cnc mill to my workshop arsenal I can't afford to buy a ready made item (yet!) and am not willing to spend the time modifying a manual mill. I expect this applies to many "model" engineers. I suspect that the proliferation of CNC is not as widespread as you suggest. It would be interesting to poll the readership as to how many actually have a cnc machine in their workshop (and that doesn't include those who use cnc for paid work, John and Andrew, and can write off their investment against tax). It would also be interesting to know how many of those who do have cnc have it for it's own sake or actually use it as part of their wider activities, be it modelling, motor cycle repair, car repair, making bits for telescopes etc. etc.

Cheers,

Rod

Edited By Roderick Jenkins on 05/01/2016 11:13:49

[Peter G. ShawParticipant @peterg-shaw75338]

I've long thought that the name "Model Engineering" is wrong seeing just how wide is the spectrum of activities that are covered. Whilst I prefer "Home Engineering", or something similar, it is a fact that "Model Engineering" is now a fixture and it will take a lot of time and effort to persuade people to change so I think we are stuck with it.

In respect of CNC, I'm one of those old dinosaurs who wish to get my hands dirty experimenting with techniques, learning how to use manual tools and get the best out of them. Don't get me wrong, my mill has an electronic controller, but that's about as far as it goes. I do have a pair of digital calipers, but I'm not exactly happy about their resolution and the fact that the power cells just don't last. As a consequence I much prefer my manual measuring tools.

Furthermore, I've no wish to go programming – I did a small amount many years ago and know I can do it, but it no longer interests me. End of story!

Agree totally with above contributors.

Regards,

Peter G. Shaw

[JasonBModerator @jasonb]

I think you will find there is a completly different skil to produce the parts from CNC its not just press a button and out comes the finished iten.

You need the ability to draw the part up in 2D or 3D depending on its complexity.

You then need to programme the machine with type of tool, speeds feeds etc then set up all the tools so the machine knows where the end of the tool is.

Then you mighty be able to produce CNC parts.

Also worth considering that any new blood comming into teh hobby is unlikely to have any hand or machining ability but will be able to work their computers

I came very close to getting a CNC machine over the christmas but I the end decided that at the moment I don't want to dedicate the time to learning how to get the best from it so at present am sticking to manual.

[VicParticipant @vic]

I wonder what CNC'ists say when someone says " did you make that yourself?" – "well yes, I pushed the start button"?!

Edited By Vic on 05/01/2016 11:26:30

[Martin ConnellyParticipant @martinconnelly55370]

There is a halfway point in home CNC between fully manual and fully CNC. I think a lot of home machinists who have CNC will work this way.

I made my machines CNC for times when CNC allows me to do things that are hard or possibly impossible to do without CNC. A lot of the time I use them with MDI (manual data input). There is not a lot of difference between turning a handle 1mm by hand and telling the computer to turn the handle 1mm.

What I get from CNC on the lathe is never having to mess about with change gears anymore. I can cut imperial threads or metric regardless of what gears I have or the leadscrew pitch. I can chose a feed per revolution and if it's not quite right I can try a bit more or a bit less on the next pass or even during the pass if it is long enough. Want to turn a bar down taking a lot of passes or bore out a small hole to a large hole? I can use a wizard and let it do the bulk of the work and take over for the manual input when I approach target dimensions. Recently I was asked to make a bellmouth for a carburetor intake **LINK** . It required an elliptical curve on the inside and a circular curve on the outside. I spent some time working out the maths equation for the coordinates for the cutter to follow then wrote a small program for the lathe. No sitting down with a PC and just putting a DXF into a CAM program. Formed the complete curve inside and out with a 6mm button tool without pausing between start of the curve and the end of the curve.

On the mill I can do a similar thing, use MDI to treat it like a manual machine with input through the keyboard instead of turning handles. Does winding a handle manually from x=100mm to x=200mm take more skill than telling the computer to move the table 100mm from 100mm to 200mm? I can tell the spindle to move down at a rate of 0.05mm per revolution to a specific depth when drilling a hole and tell by the sound and swarf coming off if it should be faster or slower feed. Does it really mean I have less skill than someone who is doing the same thing by winding a handle? I have still chosen the rpm of the spindle to suit the cutting tool the same as anyone working without CNC.

CNC does not de-skill someone, it just changes the skills used for achieve an end product. How much computer power is used to get to the end product will vary from person to person but for what I do it is only a small step away from manual machining. Hobby machining is a very wide spectrum of ability and processes.

Martin

[roy entwistleParticipant @royentwistle24699]

I get the impression that CNC is ok for manufacturing in bulk In a lot of cases, you could make the part manually in the length of time it takes to write the programe

I could be wrong

Roy

[Ady1Participant @ady1]

If you ever watch any of those zombie apocalypse type movies or series no-one can ever make anything useful.

They are all ex-service industry people, the only skilled people our society has after armageddon are nurses and doctors as far as the movie industry is concerned

They all wander about scrounging and cannibalising whats left of our modern society unable to restart human self-sufficiency because there's no-one left who can actually make stuff anymore

Ray Mears does interesting stuff on the old ways and self sufficiency of indigenous peoples and their dying skills all over the world, but he never does anything on our own societies fading skillbase

Britain has made everything by hand from shirt buttons to supersonic airliners over the last couple of hundred years and these are skills we should preserve

[John Stevenson 1Participant @johnstevenson1]

Rod makes a good point, it is for a wider audience from the support and training that I have undertaken with many people.

David's comments, with the greatest of respect are utter rubbish.

For the last at least 15 years every operator of CNC equipment in the factories we have and yes we still have a lot, has been trained on CNC machines only, no manual stuff at all.

So David is saying that everything Rolls Royce, BAE Systems and the many F1 industries based around Northampton and Bracknell that lead the world, has turned nothing but rubbish out ?

Incredible !!!!

CNC is a different skill set, just like woodworking is different to metalworking.

For a start in CNC you have a far different 'menu' to work to. In many cases with modern equipment and materials you can run at optimum speeds which makes the speeds and feed charts we have a joke.

What would you push a 1/8" or 3mm end mill thru steel at manually ? Me probably 1,800 revs and quite slow with a maximum of between 1mm and 1/16" cut, Mixing units here to please both camps.

Commercially today our intrepid CNC hero's who according to David know sod all, they would belt this thru at 25,000 revs at a speed of 28 in/min or 725 mm/min which would remove 0.00057" of material per tooth at a power loading of 0.1 HP and a maximum tool deflection of 0.0001" so well safe.

Your manual machinist would stand far more chance of breaking a tool.

Just a different skill set.

[Roger Provins 2Participant @rogerprovins2]

Posted by Martin Connelly on 05/01/2016 11:31:14:……………

CNC does not de-skill someone, it just changes the skills used for achieve an end product. ………..

Martin

I quite agree Martin. It moves the main skills needed away from mechanical engineer to computer programmer.

I've no quarrel with that – I spent much of my working life as an computer network manager.

Maybe that's why I prefer not to have computers in my hobby workshop.

Rog

Edited By Roger Provins 2 on 05/01/2016 11:47:33

[Martin ConnellyParticipant @martinconnelly55370]

Roy, most of my work on my CNC modified Smart and Brown and Rong Fu mill is done without a program. I go into the workshop and switch on the power to the laptops and machines and then do the same sort of thing any manual operator will recognize, set up a workpiece, set up the tooling. Work out the tooling position relative to the workpiece to know how much to move it to get the desired result, check the result as the work progresses. The difference is that I cause the tool to move by instructing the motion through the CNC program manual data input instead of by turning handles. No time spent programming at all for basic machining.

Martin

[duncan webster 1Participant @duncanwebster1]

Perhaps we need a section called ' dinosaur engineering' for people who see merit in doing by hand what you can get a machine to do under your instruction. Tubal Cain once did a series on how to build a steam engine without a lathe, using a lot of hand skills. Perhaps those who object to CNC will sell up their lathes, millers etc and just use files, chisels etc. In the meantime, I'll continue to boldly go, even tho' I don't have any CNC stuff I've considered it.

[Martin ConnellyParticipant @martinconnelly55370]

Good call Duncan, CNC is just another tool.

Martin

[Mark P.Participant @markp]

Horses for courses?

[John Stevenson 1Participant @johnstevenson1]

Just to add to my last post and make it clear that I'm not all about having a shop full of CNC machines at the expense of manual ones. These compliment each other.

My day job is predominantly emergency repair engineering where something comes into the shop in 7 bits and is expected to go out 10 minutes later in 1, or rather that's what they would like.

My daily work horses are a TOS 14x 40 lathe and a Warco WM 40 Bligeport type Chinese mill, heavily modified.

Both of these are manual but the CNC's are there for the jobs that are hard to do on these two machines, gear cutting of special gears is one.

From doing a lot of conversion and training of people in this hobby I find that CNC fits in with all of them otherwise they would not have chosen the path.

Where is does fit in is that many are able to enjoy more of their hobby as drawing and programming can be done safely indoors and Gert can't accuse them of being in the workshop every night as you are sat there with her, with your laptop. The result is when you are let off the lead you are ready and raring to go.

Many parts that require machining are multi sides or need 2nd or 3rd opp work like tapping etc. Now if you were doing 100 off you would set up for the 2 or 3 different operations but with only one or two complex shapes it's quicker to get the CNC to do the hard bit and then you manually finish off whilst it's doing the next part so you work smarter and faster.

Actually this way you are better than the all manual guy or the all CNC guy as you know more and are in more control.

Just the same way a DRO will speed things up.

It all depends on what you want. If you are totally old school and enjoy working with manual machines then fine, no one is saying that you have to change but if you are interested more in the finished article then CNC is one way forward. We are all different.

I know people who have used CNC or a kit built to make a loco as they want to drive it, that's their interest.

I also know people who once they have built a loco, promptly sell it and start another. They have no interest in driving it.

The worst thing anyone can do is transpose their feeling onto someone else's views. Cannot be done, we are all different and have to accept that CNC is here, is affordable to some, will not go away and has a place.

Whether it is your place is a different matter.

[Mike PooleParticipant @mikepoole82104]

For a job that can be made on a CNC or manual machine then surely what ever tool you have or enjoy using most is the way to go, CNC really comes alive when making things that are near impossible to make by hand only methods. NC was originally created to make the complex shapes and contours needed for aircraft but once the machines were built all the other uses were found.

Mike

[VicParticipant @vic]

That's interesting Martin. Not something I'd thought of.

[John Stevenson 1Participant @johnstevenson1]

Did two of these last week, no picture but these are two I do a few years ago.

Not easy to do manually to get the profile equal on both and the engraving to follow on.

Blank turned on the manual lathe then swapped over to the first X3 that got converted to CNC when ARC used to sell the kit, so not even a commercial or production machine.

No programming time as it had already been done and paid for. 45 minutes to do the profile and engraving which did require a tool change but I was doing something else.

[Neil WyattModerator @neilwyatt]

I bet they said the same things about cameras and paintbrushes.

Neil

[John Stevenson 1Participant @johnstevenson1]

Going further.

Who mines their own iron ore ?

[David Clark 13Participant @davidclark13]

I said the CNC manual millers I came into contact with were useless, not all CNC millers.

Yes, it can take longer to program a component than to make a manual component, it is all different now, all programmed on a computer. 20 or so years ago we programmed manually and a couple of days to write a program was not unusual.

Conversely it is often faster to program and make a one off than it is to do it manually. Depends on the complexity of the program.

My argument is that if designers did not use computers to design these complex components we would not need computers to make them.

A typical CNC job I did was replacement parts for a Nimrod. One batch of these were about 18inches long. They were surfaced all over, nothing was flat. The people who made the computer drawing (no paper drawings existed) had literally taken a part from an old Nimrod and put it on a CMM to produce the drawing. When they made the original Nimrod I doubt they had surfacing facilities. I think I was making brand new components that were 30 years old.

I had been working on these components for 3 weeks on nights and I came in for my shift and one of these so called CNC millers had skimmed the bottom of the components flat as they were distorted. No it wasn't distorted it was correctly surfaced. He had scrapped 3 weeks work. Not my problem fortunately.

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