Re: [CAD_CAM_EDM_DRO] Basic questions

On 1/2/2012 2:23 PM, Gordon Anderson wrote:

> Hello, I have been lurking on this list for sometime and I have a
> couple of dumb questions that I hope someone can answer for me or
> point me in the right direction. I am very close to buying a DIY CNC
> router kit like the blueChick. I have read a lot about the machines
> and control software but my questions are pretty basic and most likely
> dumb, here goes:
> 1.) How do I hold material on the table? I will be cutting thin wood,
> liteply and balsa wood. I will be cutting through the wood to cut out
> parts. My question is how do people hold the material in place and
> what do you put under the part you are cutting to make sure you do not
> cut into the bed of the machine.
> 2.) I have old drawings with patterns for formers (mostly from model
> airplanes) that I would like to convert to gcode files to enable
> cutting the parts. Is this possible? If so where can I learn more
> about the process. I hope I can scan them in and then convert them to
> gcodes.
>
> I hope these questions are appropriate for this list and appreciate
> any input.
>
> Thanks!
>
> --Gordon

How you hold things depends on the machine. My homemade router has a
wooden bed. I consider it a consumable and replace it when needed. I
either screw the material directly to the table in the scrap areas, or
use edge clamps.
If your table is not sacrificial, you can add a sacrificial layer, like MDF.

BTW, the type of cutting you describe is called profiling or profile
cutting. It is a 2D or a 2.5D process. Most routers are capable of 3d
cutting, as well.

Your old drawings can be redrawn in CAD. Scanning may be an option, but
I'd have to research it to see how to do it.
I sometimes use photos or scans in CAD and draw over them. This involves
scaling and rotating to get the orientation right.

The CAD files are sent to a CAM program to generate the G-code. Or
simple G-code can be hand written.

I just Googled Blue Chick. That design is made of MDF. MDF will absorb
moisture from the air in a humid climate and swell. It seems pretty
pricey considering ether are no electronics or motors.
I don't know what size you are looking for, but have you seen this:
http://www.zenbotcnc.com/

--


Ron Thompson
On the Beautiful Florida Space Coast, right beside the Kennedy Space Center, USA

Think, Draw, Print. 3D printers ROCK!

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