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Re: WHO NEEDS CNC?

Posted: Tue Sep 25, 2018 12:19 pm
by Bill Shields
Giggle:

this is another one of those endless discussion threads...

The Swiss were doing very accurate watch work long before any control method other than gears and cams was available....and if you are making very large numbers of the same part, the old multi-spindle, mechanical cam machine will still eat everybody's lunch.

Re: WHO NEEDS CNC?

Posted: Tue Sep 25, 2018 1:49 pm
by SteveR
Dave's work shown here (and that chucker is a real beauty) isn't really a good comparison to what CNC really brings to the table; the ability to run multiple axes simultaneously. In the video here, we see the lathe cutting in a single axis each time. On a manual mill, we (I) cut one axis at a time. CNC can cut 5 different directions at once.

The CNC also doesn't get tired as fast as I do. Sigh.

Re: WHO NEEDS CNC?

Posted: Tue Sep 25, 2018 3:41 pm
by Trainman4602
I can make that handle without the use of CNC

Re: WHO NEEDS CNC?

Posted: Tue Sep 25, 2018 4:06 pm
by Bill Shields
Only 5 directions?

A somewhat limited machine.....

Re: WHO NEEDS CNC?

Posted: Tue Sep 25, 2018 5:51 pm
by AnthonyDuarte
Practically anything that can be made with CNC can also be made with manual equipment, but it would be silly to suggest that the old ways are just as easy. Granted, in some cases they are neck and neck as far as cycle times and unattended running are concerned (the automatic cam-driven screw machine has come up), although even then, cam driven can only keep up with certain kinds of parts, whereas the modern CNC swiss lathes have much greater versatility.

A fine example of where CNC unquestionably has the advantage is turbine impellers. The earliest photograph I can find of impeller manufacturing is from May 1945. The amount of setup and labor that went into it is truly astonishing and no doubt inspiring, but let's not forget that set up and labor are the two biggest costs of a machine shop. CNC reduces those dramatically.

This has been a very interesting discussion, but as far as our hobby is concerned, I don't feel that it's productive. Discussing the economics of CNC vs Manual is only useful if it's putting food on the table. This is a hobby. The most important thing for its survival is that its participants and suppliers are interested in building. How this is accomplished is irrelevant.

Keep on making chips every one, whether it's with a chisel or the most cutting edge technology, just keep on doing it.

IMG_0406.JPG
Impeller Manufacturing in 1945
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5-axis CNC Impeller Manufacturing

Re: WHO NEEDS CNC?

Posted: Tue Sep 25, 2018 8:55 pm
by JBodenmann
Hello My Friends
Use the materials and techniques that you are comfortable with. The important thing is that YOU ACTUALLY MAKE THINGS, and don't just wag yer' chin. My hat's off to those that make things. The methane producers and criticizers well....
Happy model building.
Jack

Re: WHO NEEDS CNC?

Posted: Wed Sep 26, 2018 7:20 am
by Steamchris
Hi Guys,

i wont missing the advantages of CNC, if i havent use a cnc for milling my frame of the 611 it wont be possible to use roller bearings on axles and rods. You cant produce 2 parts with a tolerance under 0.01mm with a standard Mill. Im going with Jack,to do something is important!!

And everybody who things CNC is easier then normal milling is wrong, it is different.


With best Regards
Chris, professional CNC worker

Re: WHO NEEDS CNC?

Posted: Wed Sep 26, 2018 9:31 am
by Trainman4602
I agree about the difficulty in machining a part on any machine be it CNC or manual. What I do disagree on is that You say you would not be able to make your frames without a CNC mill if that is the way I read it.

Re: WHO NEEDS CNC?

Posted: Wed Sep 26, 2018 12:07 pm
by Steamchris
Hey,

it is possible, but not with the tolerances i want to have for using roller bearings all out on my timken runing gear.
You need the accuracy nearly zero who to use roller bearings.
You can mill all the radii and difficult shapes of the frame with only 1 tool, if you're trained to program the machine you do it in a very acceptable time and the accuracy of CNC is the biggest advantage in my eyes. One Problem i
have, im not so good in the manuel way, so my hat is of to all the guys out there , doing the jobs by the old school way.
I think it is no shame to use new and useful manufacturing technology for our hobby.
Best thing you can combine both arts.
So dear Trainman keep that good stuff coming , i like watching your Videos, you are an "old" school master guy
i always learn something. :idea:

All the very best
Chris

Re: WHO NEEDS CNC?

Posted: Wed Sep 26, 2018 2:10 pm
by Geezer
Trainman4602 wrote:
Tue Sep 25, 2018 3:41 pm
I can make that handle without the use of CNC
Yes Sir, I could also make a one piece handle on a Chucker.

Re: WHO NEEDS CNC?

Posted: Wed Sep 26, 2018 3:44 pm
by Trainman4602
To make that exact type handle I would make it in two pieces

Re: WHO NEEDS CNC?

Posted: Wed Sep 26, 2018 5:19 pm
by SteveM
I can't imagine the setup involved in manually machining that turbine impeller.

Steve