Is CNC cheating

[JasonBModerator @jasonb]

Neil, you have based the poll on cheating in MODEL ENGINEERING but Fizzy did not mention ME which is why I asked earlier if his comment was about home shop machining in general or Model Engineering

[NJHParticipant @njh]

Then your "poll" Neil is meaningless. Outside competitions there ARE NO rules hence there cannot be any cheating.

I would say that in " non- competition" mode ANY means employed to satisfy the maker's ( or maybe comissioner's !) objective is valid .

For my own part I want to do as much as possible as that is why I practice the hobby. Others may achieve satisfaction in other ways and if that involves "buying " parts / expertise that' s OK so long as they don't claim it to be "All my own work" when competing against others.

Norman

Edited By NJH on 02/09/2016 14:51:45

[Mark CParticipant @markc]

Perhaps the question being asked should be "are you entitled to an opinion if you have not tried yourself".

Could possibly role that out in it's own right?

Mark

[blowlampParticipant @blowlamp]

Often, CNC is simply the best thing for the job – it's a genuine multi-purpose tool. Why look any deeper into it than that?

For instance, how do you mill an elliptical pocket with conventional machines in a home workshop?

Martin

[JasonBModerator @jasonb]

NJH Depends how the person defines cheating. If you are saying CNC is a shortcut or easy riute to a completed item then it does not matter if its in a comp or not.

 

We should not forget that there are those who want to get onto the track or rally field as quickly as possible and may not have an engineering background so staying in a shed for 4yrs turning handwheels may not appeal to them. But should they be excluded from the hobby, I personally think not.

What about youngsters comming into the hobby (maybe even young Harriet) they will be far more savy about CNC, 3D printing, using modern materials but should they be turned away from the club because they have not made the model on a treadle lateh?

Edited By JasonB on 02/09/2016 14:45:45

Edited By JasonB on 02/09/2016 14:53:09

[NJHParticipant @njh]

 

Jason

I was posting about 3 posts up before seeing your reply!

My take is that there must be rules before there can be cheating. As far as I know anyone can make "stuff" in their workshop and there are no rules. In competitions there ARE rules and they should be followed. (Perhaps those rules  need updating?) 

As far as CNC goes it may or may not be a short cut but it is certainly a valid way of making stuff ( ? though the costs of a set up?)

It is academic though as I doubt that I will ever go there! ( CNC or competitions! ) I'm just a humble knob twiddler and bodger.

Norman

 

Edited By NJH on 02/09/2016 15:20:54

[JasonBModerator @jasonb]

I suppose each individual can have their own standard and what they feel is the right way to do things and these would become their rules. So is another person does things differently to the first persons standards then in their view that person has cheated.

J

[NJHParticipant @njh]

Sorry Jason

I think you can ONLY cheat if you break the rules – if there are no rules then you cannot cheat. The questionnaire is thus invalid.

Norman

[duncan webster 1Participant @duncanwebster1]

Posted by Michael Walters on 02/09/2016 11:07:50:

Posted by duncan webster on 01/09/2016 19:22:00:

Posted by Michael Walters on 01/09/2016 08:23:27:

Posted by Hopper on 01/09/2016 07:20:06:

Electric motors! That's where the rot set in! If you don't treadle it yourself and soak the job in your own sweat, you haven't really made it yourself!

 

Yes! I knew they were the work of the devil! Them motorcaring city folk just don't know whats good for em anymore.

Seriously though, if i can teach someone with no machining experience to run a cnc program, then surely, even the proponents have to tell you that there is obviously a descrepancy between the two. You can't argue they are equal skills.

Michael W

Edited By Michael Walters on 01/09/2016 08:27:19

But I can teach someone with no machining experience to drive a manual machine tool. I see no intrinsic difference between twiidling a handle so many turns plus so many divisions and telling the computer in G code to do it. You still have to know appropriate speeds, depth of cut, feed rate etc, and don't think you can just let the machine get on with it under computer control with an unskilled man supervising, seen what happens when the unskilled guy didn't know it wasn't supposed to make that noise, ruined tens of thousands of pounds worth of components. Sensible management puts skilled guy on, just gets more productivity.

I presume all the naysayers refuse to use the leadscrew when screwcutting, as that would be taking the skill out of it.

Thats where you're wrong duncan, alot of machine shops allow unskilled operators to mind the machines…so what i said still stands, you don't need to understand it. No more than the operators at key cutting services need to understand the cnc, i asked one guy and he said he had no idea, he just puts it in the machine and it does the rest for him.

With a turn handle you need to count the turns in your own head, you need to know what a decent cut looks and feels like. You don't necessarily need to do any of that with CNC. You can have one skilled guy setting it up and 3 guys minding a fleet of machines. Whats more, it saves you on the wage bill because you can treat the minders like dirt knowing you could replace them in a heart beat.

Michael W

 

Edited By Michael Walters on 02/09/2016 11:14:55

On repetition work there have always been unskilled or semi skilled workers operating machines. Dare I say this, even WOMEN capstan operators. I look up the correct speed on a chart (or work it out in my head if I'm feeling like some mental exercise), work out the feed rate depending on cutter speed and number of teeth, then use DRO, as counting turns is dead boring. If I'm taking a number of cuts I'll even set up the self act with end of travel switch so I can get on with something else. Typing all this lot into G code is just another way of doing it.

The only argument in my view is if you've bought bits in, or even perhaps downloaded someone else's G code. If you're then entering a competition you should declare it

 

 

Edited By duncan webster on 02/09/2016 16:28:04

[SillyOldDufferModerator @sillyoldduffer]

Perhaps some of the heat is because people may have very different motives for model engineering.

If your object is to demonstrate your personal skills, perseverance, craftsmanship and talent using classic methods, then techniques like laser cutting and CNC aren't for you.

If your object is to create the best possible model, then anything goes. CNC is just another tool in the armoury.  (Unless there are rules that forbid it.)

I find much to admire in both approaches, even though I don't aspire to either.

Dave

Edited By SillyOldDuffer on 02/09/2016 17:08:03

[Raymond AndersonParticipant @raymondanderson34407]

This thread seems to now be about how easy ??? cnc is. It might be easy if someone else does the programming and toolsetting then it is just a case of keeping your eye on things, or in the case of bar feeders it might be a "lights out " operation. The best operators programme / toolset their own machine for the job in hand. It saves the firm the cost of separate programmers.. Try doing that on a multi axis machine with maybe 60 or more tools and we would soon see how "unskilled " !!! it is. The learning curve is very steep, or in my case " vertical " The brother served his time on manual machines in the seventies and it was more or less learning a new skill set when they went CNC in the late eighties. I think there is a few folks on here that must be members of the Flat earth society.

[BC ProfParticipant @bcprof]

Of course CNC is "cheating" after all the "proper" way is to use a manual machine and twiddle the handles or a file or hammer or ……… After all time and precision are not important in our file to fit hobby are they?

On a serious note , if a cnc machine is the best tool for the job, and you have the skills to use, it then why not make use of your skill.

[brickyParticipant @bricky]

I don't have the computer nohow to be ever be able to wright a programme for cnc.I know that it is a skill and surely any skill that will produce items in hours that takes me days, and better than I can do I applaud.It can only be good for the long term future of the hobby to encourage the younger generation to take over in their own way,we have to keep moving forewards.

[SillyOldDufferModerator @sillyoldduffer]

This is how they they did things 50 years ago before CNC confused us with ethical concerns:

Severn-Lamb are an interesting discovery, new to me anyway. They still exist – shame their goodies look to be a bit beyond my means…

Cheers,

Dave

[Ketan SwaliParticipant @ketanswali79440]

I wonder what purpose this thread really serves, other then to create heated arguments in places, setting one person against another?

I wonder if the opening posters objective has now been met. If so, would it be appropriate to request one of the moderators to consider closing this thread, before it really gets out of hand?

Ketan at ARC.

[Raymond AndersonParticipant @raymondanderson34407]

Good idea Ketan, close it down before the luddites & flat earth members crash and burn.

[BowberParticipant @bowber]

I haven't been on here for a while due to work and lack of time but the first thing I see when I come on here is the age old argument about is this or that cheating. Seems to me that the OP is having a good laugh at the moment.

My opinion for what it's worth is that CNC is not cheating.

Let me explain with an example.

My dad has no formal training in engineering at all, he just bought a lathe years ago to help make motorcycle bits, he's a bit of a perfectionist and does take advise where he can get it so over the years (and a few machine upgrades) he's made 100's of parts for motorcycles and bicycles.
He cares little about feeds and speeds and just uses his lathe and mill with the experience gained over the years and can make very nice parts. Ask him what surface speed he used or feed and he'll look at you like you're daft though. I've seen him 4 flute carbide cutters on Aluminium and make it work.
He does have some idea what he's doing but the long and short is that he's used to his lathe and tools and how they work.

If I was to present him with a CNC lathe and mill he's be stuffed and there would be broken cutters and crashed tools flying along with the language, so he would have to start learning about speeds and feeds and correct tool usage, chip clearance etc, so in other words he would have to relearn a skill he thinks he already has plus how to draw the parts on a computer and then calculate the speeds and feeds, pick the correct cutter, and account for swarf clearance and waste material dropout issues in closed pockets. Once you've clicked the go button you have to have everything right.

So after completing the machining of a part with the INTENDED results he would have gained new skills and learned a lot more about the theory behind machining materials, that is NOT cheating.

Steve

[nigel jones 5Participant @nigeljones5]

There was no objective in the OP other than to experience the views of others, and to that end I now have an insight into this.

[Mark McCreaParticipant @markmccrea21094]

It may not be easier to cnc a single part, time spent drawing , creating tool paths and setup, only become efficient when multiples are made.

[Involute CurveParticipant @involutecurve]

I'm saddened that some want this fantastic hobby of home engineering to die with them, a lot of good stuff doesn't get posted on this site because of them.

Shaun

 

I'm a cheat……………….

 

 

 

Edited By Involute Curve on 02/09/2016 19:37:00

[Tony Pratt 1Participant @tonypratt1]

Posted by Mark McCrea on 02/09/2016 19:28:22:

It may not be easier to cnc a single part, time spent drawing , creating tool paths and setup, only become efficient when multiples are made.

Mark,

Got to disagree, drawings or otherwise would exist however the part was machined, set up would mainly be the same & most CNC machines have 'standard' tooling pre set. Programming can now be done incredibly fast nowadays.

It is a common but false misconception that CNC is only good for multiple parts.

Tony

[MuzzerParticipant @muzzer]

Posted by Tony Pratt 1 on 02/09/2016 19:39:03:

It is a common but false misconception that CNC is only good for multiple parts.

Indeed, try machining an oval cavity, domed surface, non-circular curve etc on a manual mill. Some CNC operations take minutes to set up (see Tormach "conversational" for example). Even if you managed to half-bake the job manually, you'd spend hours setting the work up for each different operation.

[JasonBModerator @jasonb]

A lot would also depend on the part, simple rectangular hole may not be a lot of difference but as mentioned earlier if that hole were eliptical the CNC would win hands down for a single and just get better the more there were

 

Edit Muzzer beat me to it

Edited By JasonB on 02/09/2016 20:08:36

[Neil WyattModerator @neilwyatt]

Posted by NJH on 02/09/2016 14:40:47:

Then your "poll" Neil is meaningless. Outside competitions there ARE NO rules hence there cannot be any cheating.

I made a post saying just that but i don't think anyone read it

Neil

[john swift 1Participant @johnswift1]

with so many demands on our time these days

the use of CNC tools could make the difference between embarking on a new project

or deciding you don't have enough time left in this lifetime

John

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