[marklavin]

Hello,

I am a designer/builder & permaculturist now prototyping a garden product I think will be a big seller based on the feedback I'm getting. I'm now looking at the manufacturing process and debating whether to go CNC, or just using traditional power shop tools, in this case a Festool circular saw, drill-press and biscuit grinder. The product pieces which are made of plywood are simple enough that the power tools have worked fine in building the prototypes, though I'm definitely seeing the advantages of automating the manufacture and hoping to help fund some intrepid DIYer doing free energy research with their CNC router via paying them to make my parts.

So my question is this: does anyone know the difference in terms of ecological impact of using one method over the other? Thanks.

[awerby]

I don't see a lot of difference in terms of ecological impact between making wood products with a CNC machine and making them with regular power tools. Of course, if you get more product out of your materials, for instance by nesting the parts you're cutting out, that would be a point for the CNC machine. But if you're running the CNC machine constantly but the other tools intermittantly, that power saved would be a point for the semi-hand-made method.

If you can use fewer workers by utilizing CNC technology, then you can't be blamed for the impact the workers you didn't hire have on the environment. And unemployed people probably drive less, and don't eat as much meat, so I suppose you could take credit for that, although it might not be a very popular claim to make right now...

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software

[thedave]

I know from manual machining on my own product, that CNC is much more efficient. It takes me 2 weeks of manual work to produce a batch of 100. With CNC I can do the same work in 1-2 days. Besides the machine itself, I am running fans, lights, compressor, and lots of other equipment. At the least you would be saving a ton of electricity with an automated system.

[Geof]

But you have to take into account the ecological impact of manufacturing the CNC machine in the first place.

[fizzissist]

But you have to take into account the ecological impact of manufacturing the CNC machine in the first place.

Judging by what I've seen in the marketplace, the functional life of CNC machines is much shorter than manual too, meaning more frequent replacement of the CNC machine tool.

A 1955 Monarch 10EE can make parts as accurate and as quickly as a 2010 10EE ( I'm being relative here, you know)...whereas a 1985 Wasino L3J is looking like a candidate for the scrap yard. The controls go south, the software is outdated, and the iron is tired from the production demands to justify it's original expense.

You can get your 10EE rebuilt to new, current standards easily. I don't hear of anyone sending in their 1985 Mazak in for a complete retrofit.

I think it's just an easy case of you don't get something for nuthin'. CNC is more efficient, and a little harder on the environment, but in the long run the net benefit to our quality of living outweighs the negatives. That's my humble opinion.

[underthetire]

While the monarch is a good example of metalworking, may not apply to woodworking. routers havnt changed much in years, and even so, software like Mach 3 to update the controls is cheap. And you can use that old computer sitting in the corner that was too slow for windows 7. That's re-using!

[fizzissist]

I got to thinking about routers.....
In the "old" days, you'd use a pantograph....

But manual or CNC, one aspect that throws the perspective is that a CNC spindle and axis control eats power....but pumps out the product!

A manual machine, on the other hand, may use less power, BUT, you have to run it a lot longer for the same toolpath.
... And my coffee consumption tripled when I started running CNC.... so you have to factor in the pot wattage, extra trips to the store for beans...