# CNC question



## Brutal (Oct 19, 2010)

I have a question about cnc machines. I want to know how much detail in depth one of them can do with doing a picture. and if any one here has done any art or pictures with one?


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## JAAune (Jan 22, 2012)

The most obvious limitation of CNC is in the size of the cutter. If the detail is smaller than the tip of the cutter it can't be produced. If the bit does fit inside, then the CNC can do it with more precision than any human. Time is a factor though as producing fine details can use up a lot of machining time.

Regarding pictures, the software will have a big impact upon how much detail can be had from converting photos. I've not used mine for anything more than converting line art to vectors yet so I can't tell you much on this subject. Some software is simply better than others but it'll likely cost more. I don't know which ones are good though.


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## LepelstatCrafts (Jan 16, 2011)

Hi Brutal,

CNC machine resolution depends on two main things. First is the servo / stepper increments and the second is the guide screws / threaded rods. If you have a servo that can step in say 1/4" per rotation versus a servo on the same guide rod that is 1/32" per rotation; the second will provide a better resolution. Now with the treaded rod, the more threads per inch can increase resolution too. The more threads per inch will also reduce back lash. Back lash occurs when the direction on a threaded rod is changed. It is the distance between the opposite sides of the tread engaging. CNC machines in my personal experience can go down to easily 0.0005" but they run well over $75,000. For a CNC router entry level pre-built machine you can start out at around $2,000 - $4,000 that can hold about 0.005" or so.

You also might want to research the difference between a stepper motor and a servo motor to see which system might work best for you since each has different advantages and disadvantages.

As you can imaging you need to really look into what you want as your resolution / control to determine your best path to go.

I hope this helped a little.

MIke


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## hydro (Aug 9, 2013)

If you are interested in doing relief carving, make sure that you have a good software package and a reliable post to the CNC of your choice. Everything has to work together. ArtCam has some interesting software and Laguna Tools had some very nice relief work being demonstrated at the IWF show last year.


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## DS (Oct 10, 2011)

Whenever I've done relief "carving" on a CNC machine, I've relied on my traditional carving experience to translate it. I use larger tools to block out the blank and then use different profile bits for the appropriate detail cuts, just as I might do with my carving chisels. Each gouge or chisel I might use will have its CNC equivelant. Still, there are limitations to what the machine can do, so, I always figure to touch it up by hand afterwards.

Alternatively, there is software out there that will "raster" an image using a single bit. Usually, the bit is a small tapered bullnose bit with about a 1/16" tip and it makes passes a line at a time-removing a very slight amount of wood per pass. This method typically is less regarded as artistry, or woodworking, as much as it is image reproduction-much like the output of a photocopier machine would not be called a sketch, or art.

Still, if you are producing a single piece, a CNC will likely prove more work than traditional carving. If you are producing two, or, two thousand pieces, then writing the g-code will be more worthwhile.


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## oldnovice (Mar 7, 2009)

I haven't done any duplicates but I have done some test runs and Doug is correct. If you are just doing one, it's more fun without a CNC but if you are going to make more then a CNC is fun too!

There is a lot of software available for almost any CNC "adventure" but, it is NOT FREE and becomes an investment like any WW tool!


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