example cad dwg files for cnc cutting

charonme · Post by **charonme** » Tue Jul 03, 2007 10:26 pm

I would like to have some things cut by a cnc service i found, but naturally they need a cad dwg drawing. Does anybody have some examples - like a case or a side panel with cut marks in a .dwg file? After I draw the thing I need to cut, how do I draw the cuts? Thanx

BIONIC_EARS · Post by **BIONIC_EARS** » Wed Jul 04, 2007 12:42 pm

All you need for CNC is a simple vector drawing of the design, perhaps indicating from a point on the drawing the distance to one vertical and one horizontal edge of the side panel for positioning. Or you can include an outline of the side panel in the drawing.

The cuts should be self-evident, but you could shade the empty space (or the panel area) for clarification.

efcoins2 · Post by **efcoins2** » Thu Jul 05, 2007 2:30 am

I use

http://www.vectorengineer.com/

cheap/free not that good but it works

charonme · Post by **charonme** » Fri Jul 06, 2007 2:28 am

This is my first try, it's a jpeg screenshot from the dwg file (click to enlarge). White lines outline the low profile heatsink with its fins that I want to cut, red lines are the required cut. I sent it to the cnc cutting shop, but it will take a while for them to answer.

Any suggestions please?

BillTodd · Post by **BillTodd** » Fri Jul 06, 2007 3:35 am

Well, that drawing alone would not be sufficient for me to make it!

Initially it looks like you are dividing the heat-sink into six parts, but you have a confusing/misleading vertical red line that only partially bisects the part.

There are large white rectangles which are presumably hidden detail (i.e. detail that is hidden in this view of the object) if so, they should be dotted/dashed lines.

Your drawing has to convey ALL the information the machinist will need to make the part, he will not want to guess what you require or have to make assumptions like the above.

For instance: Your red line cuts have no thickness, but the cutter will remove material so, do you want it to follow to the left of the line, right of the line or equally?

Dimension important parts clearly .

Give at least three orthoganal views of the object; http://en.wikipedia.org/wiki/Orthographic_projection http://en.wikipedia.org/wiki/Engineering_drawing

Above all, talk to the person making the part for you, provide him with all the information he needs to make it.

http://en.wikipedia.org/wiki/Technical_drawing

BIONIC_EARS · Post by **BIONIC_EARS** » Fri Jul 06, 2007 5:11 am

What is your plan? To cut a 2D design out of a panel, or make a 3D object (heatsink)?

If it's the latter, then you will definitely need a fully dimensioned CAD drawing.

Or is it a 3D design out of the panel?

charonme · Post by **charonme** » Sat Jul 07, 2007 1:55 am

Thanx for suggestions. My plan is to take an existing heatsink and cut it to more small pieces. All "partial" cuts are intended as they are drawn. I'll work on the 2 other projections, make dotted lines where they are not visible and fill solid parts with grey color, add dimensions. When the cutter will reply to my email, I'll ask him about the thickness of the cut lines.

TMM · Post by **TMM** » Sat Jul 07, 2007 6:26 am

If you already have the heatsink and all you want to do is a few basic cuts, don't get it CNC'ed, just cut it with a hacksaw.

Meato · Post by **Meato** » Sat Jul 07, 2007 7:02 am

TMM wrote:If you already have the heatsink and all you want to do is a few basic cuts, don't get it CNC'ed, just cut it with a hacksaw.

^^woohoo saw time! just be sure to clean up the edges

BillTodd · Post by **BillTodd** » Sat Jul 07, 2007 7:22 am

TMM wrote:If you already have the heatsink and all you want to do is a few basic cuts, don't get it CNC'ed, just cut it with a hacksaw.

That's what I'd do

I cut the heat-sink for my PVR with bench saw (wood saw). Just make sure you lubricate the blade. The Edges were pretty good, didn't require much finishing.

The two bits formed the side of the PVR's case:

You can see the size of the thing here, on the spare bit I used for the VESA ITX case (unfinished):

BIONIC_EARS · Post by **BIONIC_EARS** » Sat Jul 07, 2007 9:48 am

I've cut small heatsinks with precision using a basic metal saw. It's not at all difficult. Aluminum and copper are soft.

Make sure that the heatsink is not put together in such a way that the fins will come apart when it's cut up.

If you insist on having the CNC service do it, dimension the cut lines, make the heatsink outline less prominent (grey/fainter), and perhaps include a drawing of the pieces separated from each other slightly to provide a clear visual of the final result.

example cad dwg files for cnc cutting

example cad dwg files for cnc cutting

first try

thanx