What does CAM do? Do we need CAM programs?

[Gerald_D]

Somebody shyly asked me in an e-mail:

I may have an opportunity to pickup MasterCam version 8.0 for a very inexpensive price (used). This is my first experience with CNC and I don't even know what the software will do for me. I've been in the CAD only business for about 10 years of my life but never CAM or CNC.

This is a lot easier to try and explain to someone who already has CAD background http://www.mechmate.com/Forum/clipart/happy.gif . . . . .

Lets say you have drawn a square 100mm x 100mm [4x4"] with your CAD system and now you want your CNC to cut it out of 18mm [3/4"] thick plywood. You can need a way to convert your .dxf file to "machine commands" which is going to tell the machine:
1. take a 6mm [1/4"] diameter cutter
2. move the router head above the surface of the wood to the bottom left corner of the square.
3. switch on the router
4. plunge the cutter vertically to 6mm [1/4"] deep
5. move the cutter along the left side of the square at 50mm [2"] per second.
6. travel a distance of 106mm [4.25"] before turning sharp right.
7. do step 6 four times
8. go another 6mm [1/4"] deeper
9. do step 6 four times again
10. go another 6mm [1/4"] deeper
11. do step 6 the last four times
12. pull cutter vertically up
13. switch off router
14. move "head" to "home" position

a CAM program takes your dxf and spits out a long list of machine instructions for you. It asks you some questions along the way....eg. it may ask you what cutter diam and move speed you always use for 18mm plywood and then for future jobs it will use the same parameters.

Notice that step 6 added some extra distance to move the cutter so that the remaining square was on size - if you wanted a hole that size, the CAM program would make a different adjustment.

A CAM program makes life a heck of a lot easier for CNC work. Some CAM's are way more efficient than others - some handle 3D, others don't. Some are very pricey, others are free.

MasterCam is one of the top CAM programs, but I have no experience of it.

[reza forushani]

What is the process of generating G-code. For example if I use a software like Vcarve, how do I get that to Mach?

Let's put it this way. What programs do you use on your Mechmate?

Now that I have Mach3 installed, what do I need to do to set it up for Mechmate?

[Gerald_D]

You just tell VCarve right at the beginning that you want a G-Code output. And then you always get a file that you can load directly into Mach.

We do use VCarve at times, also SheetCam, MeshCam and Vector. Most of the time we are in AutoCad though, but that was our forté before the CNC came along and we stuck with it.

Choosing the right software depends on the type of stuff you want to cut, but 99.9% of all software will give you a G-Code file that can be read directly by Mach. That is the beauty of working in an "industry standard" like G-code.