Time for a name change?

[VicParticipant @vic]

As expected there are some interesting points of view on the subject but some folks have lost sight of the fact that this is "Model Engineer" not "production engineer" or "jobbing engineer".

[EmgeeParticipant @emgee]

Posted by roy entwistle on 05/01/2016 11:32:46:

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

I have old hat Emco cnc machines, Compact 5 lathe and F1 mill, both operate using G&M codes either manually entered on the control panel or downloaded from a computer.

In reply to Roy the following 4 lines of code take less than a minute to enter and will face the end of a bar and turn it down on diameter for the given length. The program below is in Incremental mode but could also use Absolute mode, or a mixture of both. The tool is at known diameter and on line with the end face.

M03 Start spindle (0,3,-,INP) 4 keystrokes at panel

G X Z F H (code, X axis/cross slide, Z axis/saddle, feed rate, division of cuts)

G88 -1000 -100 100 50 Facing cuts 2 passes at .50mm DOC to face off 1mm total at 100mm/min

G84 -200 -2100 100 50 Longitudal turning 4 cuts of .50 DOC reduce diam by 4mm for 20mm length on bar.

M30 END of program, also stops spindle.

G88 and G84 are both cyclic codes and the tool returns to the origin after each cycle. It's possible to change spindle speed and feed rates during the program run.

Having used manual machines for many years and cnc for a few my vote is for a mixed machine workshop, like most thing it's great to have a choice.

Emgee

[Halton TankParticipant @haltontank]

I must admit that I find the OP view disappointing and myopic. It would appear he thinks that hobby should only consist of using hand tools and manual machinery, and anything that smacks of automation is heresy. As other posters pointed out CNC, especially home/hobby type has moved skill into different areas.

I do sometimes wonder if this sort of die hard attitude to anything is one the reasons for the decline of the hobby, I see quite a number of clubs have the word 'Experimental' in their title, but I do suspect quite a number of their members would accept any thing only on the pain of death.

I accept that the title of 'Model Engineering' for the hobby is a bit of misnomer and we should take broader view rather than the literal meaning, but the important thing to remember is that it is a hobby and we partake it in to enjoy our selfs. So whether you prefer spending your time twiddling the handles of your lathe or banging away on the keyboard, it really does not matter as long as you are enjoying yourself. The only thing I would ask is that you respect that other people have different view of the hobby, as you would expect them to respect your view.

Regards Luigi

[BazyleParticipant @bazyle]

ME has multiple subsets covered in the magazine –

TEME – Traction engine model engineering
CME- Clock model engineering
BME- Boat model engineering
LME- Locomotive model engineering
and so on.

If you want to change the name you could follow the Americans with Home Shop Machining.

I think it would be really bad for us, the consumers, to encourage any such divisions as that makes the publishing house managers think they can spawn another magazine for the speciality. That dilutes the original ME, sucks advertising revenue out of our suppliers and subscriptions from us for what is a fairly limited and only just adequate number of authors.

[Brian AbbottParticipant @brianabbott67793]

For me its simple ( Like me ), I want to produce a model that is pleasing to me using whatever skills I have to hand ( or can learn ).

I would get no more pleasure spending 2 days crafting a part which I could produce in 4 hours using Vero and a Hurco,

Cnc to me is a fantastic development, I work in a factory which employs high speed machining and 5 axis laser cutting, etc, etc, and I find it all fascinating.

and when i am called to the latest smash up in the press, and I have little to no time to reverse engineer all the broken bits back together I am quite happy to reply on the modern approach.

[Another JohnSParticipant @anotherjohns]

Posted by Roger Provins 2 on 05/01/2016 10:26:43:

… 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.”

Roger – I would suggest (nicely, no malice intended) that the expression "walk a mile in my shoes" applies here.

How many of the detractors of CNC have actually:

1) used manual machines to make things,

AND

2) used CNC machines to actually make things?

I would expect about zero of the detractors of CNC have actually produced things from both CNC and Manual.

I think that Brian (in your quote) is simplifying things somewhat – for instance, the learning of the skills required to make it look easy is always a time-intensive, educational process.

As Martin, JohnS and others have said – they are all tools, and we use them to produce our models/products/whatever.

Another JohnS.

[Roger Provins 2Participant @rogerprovins2]

… well that got the sort of replies I expected and woke the place up for a few minutes

[AjohnwParticipant @ajohnw51620]

Having heard some very expensive machining centres being set up I know that David Clark made a good point early on.

Speeds, feeds, cutters etc have to be chosen and cnc as far as I am aware doesn't really offer anything at all in that direction. It still needs a skilled setter especially if it's being used for manufacture as time costs money, as does the machine. CNC in this respect isn't much different to old style auto's and capstan machines etc. They need a setter and an operator as in many cases a person who is sufficiently skilled at setting would have little interest in actually operating the machines all day churning out parts. CNC in real terms removes the need for a semi skilled operator.

Not at our level but cnc can be more flexible. One single machine can mill and turn and even grind. The grinding was an attachment on one smaller machine I have heard of but in real terms that could be built in too. However there is some indications that cost wise special purpose machines can beat them or even old style labour intensive methods at times. That area was also likely to use special purpose equipment. I suspect the bean counters don't like employing people who can design them.

John

–

[Raymond AndersonParticipant @raymondanderson34407]

Hi JS, Just noticed that in an earlier post you said that there are no apprentices trained on manual machines these days, all cnc, Well I beg to differ, because one of me brothers [who is a foreman turner ] at his employers all the apprentice turners and millers are grounded on manual machines first then move on to cnc 3/4/5 axis

All the manual machines are DSG, Bohringer, Cincinatti, Parkson , the cnc ones are a real Dolly mixture of , DMG Mori Seiki, Gurutzpe ,Hermle , Waldrich Siegen and WFL, They are used for making large, to very large, oilfield components. That concept might be a rarity now but thats how it is there , and they produce some cracking operators. Many have went on to start their own firms , so it does still happen.

cheers.

[Ralph HParticipant @ralphh]

It is definitely a question of perspective. I look at CNC as an immensely useful and beneficial tool for every purpose, be that at work or home, but it is not my personal interest to use it. I think if everyone used it the hobby would be de-skilled, but not in so much as CNC being less skilled but the ability to make things by hand would be lost over time. CNC requires a different skill set, many of the skills needed for manual and hand work are simply not needed and it cna be used to make geometrically complicated components vastly more easily and efficiently than by hand. At the end of the day this is a hobby, not a job, and it is personal preference and interest that dictates. I do a lot of CNC at work where it is indespensable, but none at home because my personal interest is in older technology and hand skills.

[Ralph HParticipant @ralphh]

And Raymond yes, you are right. That is still done for the most part these days, at least everyone I have been. Colleges teach with manual machines, you go onto CNC after a grounding in what they term the "basics".

[Ian S CParticipant @iansc]

I can imagine that early in the twentieth century there was similar argument when electric motors were being stuck on lathes, replacing the foot motor. The CNC machine is just another tool that is available to the model engineer, along with 3D printing, I don't suppose there are too many who have their own water jet cutting plant(yet).

Ian S C

[John Stevenson 1Participant @johnstevenson1]

If one reads my posts carefully, something rare on this board I think ? You will see I'm not advocating CNC over manual or manual over CNC but say that we should accept the new technology as it arises.

To many people are putting their own prejudice's forward as the views everyone should take.

That is not the way, there will always be a divide, much like the metric / imperial argument but all one needs to do is see both sides of the argument and then make you mind up how it affect YOU and not preach.

[Ralph HParticipant @ralphh]

I think that is well said John and Ian S.

[John Stevenson 1Participant @johnstevenson1]

If say 15 to 20 years ago you had gone to the Model Engineering Exhibition at Wembley or Ally Pally and some one had stood up and given a lecture and said that in 15 to 20 years time into the future a Model Engineer could easily have a CNC lathe, CNC milling machine, laser cutter and a 3D printer in his little shed he would have been burned at the stake as a heretic.

And before someone pops off about cost, add all those 4 things together and it's less than I dare say many on here, me included have spent on a new car, or in my case "The Donald ™"

Another 2 years and that will be ready for the scrapyard whereas all 4 items I have mentioned will probably well outlast me.

The most valuable commodity we have now is time. Without getting personal or morbid as you get older it runs out quicker. There is no longer 24 hours in a day as they were when we were younger.

When we were younger we could do a lot in 24 hours, but as we get older and slow down then we can't fit it all in a day. Some days I only manage a 5 hour day

We have more trappings around us that require attention. Two cars to clean instead of one. I'll bet many of us can remember early on living in rented accommodation where it was the landlords job to do the upkeep.

Now we have bettered ourselves from the two up, two down, arse on the step putting your boots on on the pavement. However it all takes time.

I'll bet we can all remember skiving off into the shed [ never had workshops them ] 4- 5 nights a week and probably part of the weekend. Doesn't happen now does it ? And we won't mention IKEA or Dunhelm Mills.

This is where the new technology can help. Take CAD, many here use it and it's not got the Darth Vader reputation like CNC although it's only 2 steps away. So you sit there at night whilst DeadEnders is on the BBC because if you skive off again it doesn't go down a bundle. So even if you have drawings, transposing them into CAD gets the part in your mind and you do all the mental moves ready for when you cut metal by what ever method. This will probably save you time in the shop and also you should be getting good at spotting pratt falls before you scrap a part.

[VicParticipant @vic]

Posted by Ralph H on 05/01/2016 13:41:53:

It is definitely a question of perspective. I look at CNC as an immensely useful and beneficial tool for every purpose, be that at work or home, but it is not my personal interest to use it. I think if everyone used it the hobby would be de-skilled, but not in so much as CNC being less skilled but the ability to make things by hand would be lost over time. CNC requires a different skill set, many of the skills needed for manual and hand work are simply not needed and it cna be used to make geometrically complicated components vastly more easily and efficiently than by hand. At the end of the day this is a hobby, not a job, and it is personal preference and interest that dictates. I do a lot of CNC at work where it is indespensable, but none at home because my personal interest is in older technology and hand skills.

Very well put Ralph.

[Roger Provins 2Participant @rogerprovins2]

Posted by John Stevenson on 05/01/2016 14:35:39:

If say 15 to 20 years ago you had gone to the Model Engineering Exhibition at Wembley or Ally Pally and some one had stood up and given a lecture and said that in 15 to 20 years time into the future a Model Engineer could easily have a CNC lathe, CNC milling machine, laser cutter and a 3D printer in his little shed he would have been burned at the stake as a heretic.

And before someone pops off about cost, add all those 4 things together and it's less than I dare say many on here, me included have spent on a new car, or in my case "The Donald ™"

Another 2 years and that will be ready for the scrapyard whereas all 4 items I have mentioned will probably well outlast me.

The most valuable commodity we have now is time. Without getting personal or morbid as you get older it runs out quicker. There is no longer 24 hours in a day as they were when we were younger.

When we were younger we could do a lot in 24 hours, but as we get older and slow down then we can't fit it all in a day. Some days I only manage a 5 hour day

We have more trappings around us that require attention. Two cars to clean instead of one. I'll bet many of us can remember early on living in rented accommodation where it was the landlords job to do the upkeep.

Now we have bettered ourselves from the two up, two down, arse on the step putting your boots on on the pavement. However it all takes time.

I'll bet we can all remember skiving off into the shed [ never had workshops them ] 4- 5 nights a week and probably part of the weekend. Doesn't happen now does it ? And we won't mention IKEA or Dunhelm Mills.

This is where the new technology can help. Take CAD, many here use it and it's not got the Darth Vader reputation like CNC although it's only 2 steps away. So you sit there at night whilst DeadEnders is on the BBC because if you skive off again it doesn't go down a bundle. So even if you have drawings, transposing them into CAD gets the part in your mind and you do all the mental moves ready for when you cut metal by what ever method. This will probably save you time in the shop and also you should be getting good at spotting pratt falls before you scrap a part.

With the greatest respect John you have depicted one live style, probably yours, but this is not representative of us all. Certainly bears not relationship to mine.

I can still mange 10 hours a day when needed, I'm 73.

Have only one car not two and the rain cleans that.

Never had rented accommodation.

Never had a two up two down.

Never had to skive off to a shed, my wife never complains – she has her own hobbies.

Never shop at Ikea or Dunhelm.

Never have watch TV if I don't want to and I can't imagine my wife watch Eastenders or other crap.

So, as has been said, we're all very different.

Rog

[Michael GilliganParticipant @michaelgilligan61133]

I have no desire to answer Roger's provocative question, but I would like to share what I consider to be one of the finest examples of CNC and hand Craft being used in sympathy … each in its proper place.

Have a look at the three-legged Bridge in Fig. 11 of this article.

MichaelG.

[MalcBParticipant @malcb52554]

Another plus from me for Ralph H.

Was heavily involved with the introduction of our first CNC in the early 80's, being one of the first programmer/setter/operators, moving on to planning and production engineer, then works manager with Director status responsible for then for the full CNC justification and implementation programme within the company with a much hands on throughout.

In those early days it was exciting times with much training and development to be done by myself and those following along. The company still does operate conventional machines along side the CNC because as others have stated full programming and setting cannot always be justified in production costing. All our operators are fully competent programmer/setter/operators.

Now that I am semi retired I actually find it more exciting going back to the basic machining skills gained in my earlier toolroom years.

Would I have CNC in my home workshop ( if I had room ) – No Thanks, I love the basics albeit I do find DRO so good in there.

I do have a lot of respect and understanding for people who do want to go down the CNC path who havnt yet done it, it is very exciting and challenging learning the new skills and disciplines required. There is a real feeling of achievement when things go right.

There will always be people who want to do go that way, but I suppose there are people also like me who after having heavy CNC involvement find it refreshing to get away from it.

[colin hawesParticipant @colinhawes85982]

If I had a CNC mill I would occasionally use it, not only because it can produce profiles that would require tedious effort to machine manually, but for it's ability to do so in 3D and also engraving. However , most of our models were originally made using manual machines and so CNC is not essential for those, but the satisfaction of seeing a CNC carrying out your carefully planned instructions is considerable and you can do your bench work while the machine gets on with it's work. Will I buy a CNC?…. no, because it takes too long to create the program for the sort of work I do and when I design something I ensure that it can be machined on what I have. Before I retired I used NC and then CNC machining centres for small batch runs and was happy to let the machine do the work. I still like to use my old manual machines just as much though .

Newcomers to engineering should note that old machines can produce excellent work; you don't need to spend a fortune on machinery for hobby use. Colin

[Trev67Participant @trev67]

Hi all

The question of new technology, and whether it should be adopted and whether it is cheating has cropped up over and over again.

Consider this:

In LBSC's day with limited equipment many would buy, say a loco frame stretcher casting, file the ends square drill and fit.

Nowadays maybe you would draw it in CAD, get it laser cut, braze together etc, or maybe model it in 3D CAD, write code maybe with CAM assistance, set up and CNC machine it from solid.

or another case:

Buy a wheel casting, machine and fit

or

Model in CAD, CAM and CNC machine from solid.

Who made more of it themselves?

Staying with locos, what about laser cut platework and frames, ready made boilers, lost wax castings etc.

The perception that cnc isn't skilled or isn't your own work seems to be a fallacy, especially when the hobbyist may have built or converted the machine themselves, learnt CAD, CAM, G code and how to set the machine up.

Anyway each to their own, and it's better to be making stuff or learning something than watching deadenders all evening

Trevor

[JasonBModerator @jasonb]

As I'm not one to bash out yet another LBSC or Greenly design but prefer to make something that has not been modeled before or maybe an existing design to another scale CNC would be very usefull to me as it would allow me to produce "castings" from a solid piece of the most suitable material that would otherwise take a lot of time & effort to cut from solid or have to compromise on material so that it can be soldered if made from several parts. How many here don't buy castings for their trains and make all the bits manually themselves, not many I should think!

I could also have it carve out say small steam/fuel fittings rather than again solder them together and also quickly cut a pair of nest jaws from say nylon so that I could then easily hold the odd shaped fitting while I manually turn/thread the connections. Again how many buy ready made fittings that may do the job but don't really look the part as they are not available or would take a lot of work with manual methods.

And for the rivit counters what about being able to thread mill all your studs to have exactly the same length of thread with no risk of the short ones spinning round in the chuck as you try to thread them

Its a pity we don't have more model makers on here who show how they integrate CNC with manual, other forums I frequent have quite a few, maybe if you saw there work it would convert the odd boubting Thomas.

J

[John HaineParticipant @johnhaine32865]

I'm a bit trepidatious weighing in to this thread, but here goes anyway! As I work in front of a computer all day long I never thought that I'd get interested in CNC, but 20 years or so ago I started to put a workshop together and got involved in "model engineering" (though I've never built a model and don't suppose I will). Initially I was getting fed up with changing change wheels on the lathe and never having a fine enough feed so started to investigate "digital screwcutting". The lightbulb moment was when Tony Jeffree published his ML7 CNC conversion and I realised that it would be just as easy to add a second stepper to the lathe and just use a general purpose driver like Mach3 rather than a single-use package. Since then I've added a CNC mill (not converted by big VMB yet) and digital dividing.

I really don't recognise what some people are saying about CNC in this thread. In my experience….

It isn't about "programming". I seldom or never directly write G-code. I use the wizards in Mach3 Turn a lot, but I must say that you need to keep a careful idea on their output otherwise the tool can do some unnerving and dramatic moves you don't expect! If I have to turn to a shoulder, that takes about 2 minutes setting up the wizard which generates the code and the machine runs. But setting the tool accurately, selecting the right feed rate and DOC, are key to getting the result you want, and you need to use the wizards as just a starting point if you really want accuracy. This takes skill and experience – just as much IMHO as manual turning, and at least you don't have to stand in front of the lathe inhaling coolant fumes while you twiddle handwheels. As for threading, there is no comparison – just look at the endless debate on change wheels on this forum, and "can you cut metric threads on an imperial lathe?". With CNC, it's a doddle, any (sensible) pitch, at normal turning speed, up to a shoulder, the machine does the pickup.

"CNC is only for quantity production" – rubbish. I have just started making Woodward's Gearless Clock, with the count wheel (which looked to me the hardest bit). I could have crossed it out with a piercing saw and filed to the line once I'd cut the teeth. But I would probably have made a mistake and might have had to start again. But I spent an enjoyably challenging hour or so writing a spreadsheet to work out the dimensions for any 4-spoked wheel cross-outs and directly generate the Gcode. I made a simple jig to hold the wheel, held it down with a bolt and some shellac, and did the crossing out on my little CNC mill. A job I found full of interest, and much more appealing than hunched over a cutting-V breaking saw blades and getting brass dust in my socks. There will be another interesting challenge in producing the 'scape wheel, and I'm especially looking forward to the design of the daisy wheel! When I've finished I'll have some jigs and programs to make more clocks if I want…

A while back I looked at producing gear cutters using the "button" method, and posted on here describing how I did it (the practical bit at least). Again that involved writing a spreadsheet that started with Mike Cox's formulae and generated the Gcode to drive the tool to turn the profile on the cutter. With this I don't have to make different buttons for each module, I can make cutters for modules and pressure angles that are impractical by the conventional method, and this would have not been possible without CNC! Similarly I've generated code for tapers that can't be made with the Mach 3 wizards. I have a plan for a pendulum compensation scheme that needs a carefully shaped cam – not possible manually, trivial with CNC.

How many plans have been published for ball turning tools? A hardy perennial. Redundant with CNC. You want to turn an ellipsoid? a hyperboloid? Easy.

Having a CNC mill, I was easily able to knock out an engraved plaque for a Jubilee Oak Tree in our village. And to produce a small memorial plaque for my woodworker father-in-law's ashes engaved on a sliver of oak from the Victory (don't ask how he got it).

[John HaineParticipant @johnhaine32865]

"It's very expensive". Hmm. Well I already had a normal lathe, converting that cost me probably less than £150 and half of that was a second hand PC for the workshop. Based on my experience with the Novamill converting a mill can be done for not a lot more than £150 (there's an extra axis) if you already have a computer (less if you don't mind sharing the drivers between lathe and mill). The electronics isn't rocket science, and you can buy pre-built boxes if you want to. As for software, yes I bought a Mach3 licence which costs a bit, but you can get LinuxCNC for free (but it's tricky to set up). I'm still trying to get to grips with CAD/CAM, but manage pretty well with g-simple CAM (free), the wizards in Mach3 and my own spreadsheet methods.

But I guess that when flint-knappers saw people smelting copper and tin and making fine, sharp bronze axes, they said that you could never make a proper bronze one unless you'd served an apprenticeship chipping flints…. I read Geoffrey de Havilland's autobiography a long time back, and he had a stroy about an apprenticeship exercise (at Cranwell?) for aircraft fitters where they were given a couple of lumps of steel, files, hacksaw and cold-chisel, and had to make a mating nut and bolt! (No, I don't know how they'd do it either!) Why deny ourselves the use of the best tools around just because we are amateurs?

Twas ever thus. Ours is a broad church, and we need to recognise we all have different interests and methods. I've spent most of my life doing professional engineering which by its nature mainly uses paper, pen and computer, with no requirement since my days on the electronics bench for hand work. At this stage it's too late for me to build up the manual skills, but it's huge fun learning about computer controlled tools and how to apply them. But equally it is great to see the wonderful things that people produce from more "traditional" tools.

[Bob RodgersonParticipant @bobrodgerson97362]

Up until a few years ago I would never have thought I would end up using a CNC machine in my workshop. However, with increasing requests to making things like crank cases and other 3-D shapes I thought that I might benefit from CNC's capability.

I imported a Tormach Mill about 2 years ago which initially I did not use because I had to rearrange my entire workshop to accommodate it which took at least 6 months. Once I got the workshop started out I started, very slowly, to learn how to use it. I spent a lot of time learning about G-codes, 3-D drawing and CAM software and continue to do so but the more I learn the more I find I am using it.

Conversational programming in Tormachs Path Pilot is very good and you find that you can make one offs almost as quickly as you can on a manual machine once you learn how to set up the machine and input tool offsets etc. Like John I try to avoid making up my own G-code but I also couldn't find a wizard for machining a tapered bore (I have a duality lathe that fits onto the bed of the mill that can be used as a CNC lathe) so I developed my own G-code, I also have had to develop another programme for facing a L.H. facing surface.

I can make anything in metal (or just about anything) by hand and I have found the new challenge of learning how to use CNC machining techniques very rewarding, if not a little time consuming. I am sure given another year or two and I will be using the CNC machines every day along with my manual machines and fitting techniques.

[Author]

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