In preparation for learning how to do the whole process from conception to milling, I wanted to take a first step in dabbling with 3d CAD. I found several free packages to try out at http://freeware.intrastar.net/cadsoftware.htm . Has anyone used any of these, and if so, could you recommend which ones to use or which ones to stay away from? Thanks.

MINOS 2
BEHEMOT
POV RAYTRACER
CADSTD
DESIGN WORKSHOP
TURBO CAD LITE
FREECAD
DESI - III
BEAMBOY
1D STOCK CUTTER
INSTACAD
CORNER
A9CAD
POWER SYSTEM SIMULATOR
DWG GATEWAY

Do you have any 2D CAD experience? If not, I'd recommend starting with A9CAD. I have it installed on my PC, and it functions very much like AutoCAD, although with a MUCH smaller feature set.

Most of the stuff on that list are not CAD programs, some are dead links.

You mentioned 3D CAD, but I think you'll find that 95% of what you see made on this site with routers is 2D, or 2.5D. You may not even need 3D at all.

POVRay is an opensource rendering program, not really intended for any kind of CAD use.

Thanks y'all. No, I don't have any 'true' CAD experience although I believe I understand the mechanics of CAD drawings. I just don't have experience using a 'CAD' product. You're right, 2.5D is all I'll probably need for 95% of what I want to do.

I've had A9CAD installed for a while for the sole purpose of viewing DWG, etc. files but I've had difficulty trying to actually use it. I'll spend some time with the manual. The LAST thing I wanted to do is to pick one myself (flip a coin) and weeks later find out I could have made a much better choice. Thanks again.

Rance

"The LAST thing I wanted to do is to pick one myself (flip a coin) and weeks later find out I could have made a much better choice."

Excellent point. It is a shame to spend time learning the intricacies of a program only to find that the same energy could have been invested towards mastering a better product.
With that in mind, Rhino has a free trial , it only allows 25 saves but the trial is full featured and otherwise unlimited. Caution . . . by the time the 25 saves have been used you'll be Googling for Rhino retailers.

Hey Rance,

I just wanted to give my experiences. I am a sign maker and run a computer all day, so I thought that going to a CAD program would be easy. HAHAHAHA! Not quite, I found a whole new world. The sign program I run is very intuitive, it is obvious what the icons stand for, etc... Cad programs are not this way. Most assume you have mastered autocad, THIS REALLY SUCKS! I had not even looked at autocad before dableing in CAD.

Now that I have vented my frustration :), here are my picks from the list: Cadstd for 2d, Minos for 3d. I tried several on your list and uninstalled them but I found these decently easy to understand. I am by no means proficient with either one but they both have decent options and user interfaces. Minos is amazing considering you could run it on a 286 machine. Definately download the manual. Cadstd has a very good online tutorial that you can even take a test on the individual chapters of the tutorial.

There is my 2 bits worth, hope it helps.
Jimmy Southern

Here's a quick A9CAD tutorial.
1) there are 4 buttons at the bottom. ORTHO constains your lines to vertical or horizontal when on. Click it off to draw at other angles. OSNAP will automatically snap the cursor to different points. You set the options in the snap toolbar. I'd recommend turning on Endpoint, midpoint, perpendicular, and centerpoint. I personally don't use grid and snap.

2) use either the draw line tool, or draw polyline tool. To start at a specific coordinate, just type it in, EX: 5,3 will start from X=5, Y=3.

To draw to a point relative to where you are, enter @6,2, which will take you from 5,3 to 11,5. Hope that makes sense.

You can always enter exact coordinates, x,y and relative coordinates @x,y. To draw an angle from a point, use @ again for relative, and enter distance>angle. To draw a line 5" at 20°, enter @5<20.

These few things should make things a lot easier to get going. If you need any help, ask away. I've never used it before, but it works just like AutoCAD, as far as I can tell.

Oh yeah, one last thing. after you're done drawing your line, just right click to end the command. Much quicker. :)

Other people have recommended some of the other packages. Since I'm familiar with AutoCAD, I like A9CAD. For 2D (2.5D), it should work just fine for what you need. Imo, once you get the basics down, you should be able to do things quicker in A9CAD than just about anything else. If you still can't get the hang of it, I might be able to do a little tutorial with pics to help you out. Let me know.

I start to use autocad lite (2D) and can do some basic drawing.

But how to go from here?
I've been reading and it looks like you have to draw just as it will be cut: startpoint, direction etc. Also you might need to compensate for the tool radius and...

Suppose I want to route a few rectangles and drill 8 holes of 2 different diameters.
What's the best and easiest way to make the drawing and convert to G-code.
I know of the following:
ACE, but needs to be drawn for tool compensation.
Sheetcam, looks complicated for a beginner.
Kcam4?

Thanks,
Luc.

But how to go from here?
I've been reading and it looks like you have to draw just as it will be cut: startpoint, direction etc. Also you might need to compensate for the tool radius and...

Suppose I want to route a few rectangles and drill 8 holes of 2 different diameters.
What's the best and easiest way to make the drawing and convert to G-code.



You are pretty much correct. With just about any of the free converters I've seen, you draw it like you want it cut. Use the offset command in your CAD program to compensate for the tool radius.

The next step up would be SheetCAM. While it may look daunting, if you do the tutorials to find out how it works, you'll find it's not that difficult at all. And it will give you a lot more control than you can get with ACE.

God