Very Basic CAM Questions

[kochevnik]

I've got some idiot questions about CAM software ... basic things I've never understood. Keep in mind that up till now I've never used CAM software on my mills, just straight GCode.

So one of the things I don't understand is: say you have a simple part like a 6 sided cube that needs milling on all six sides. And let's say if I was just writing GCode I might have six different programs one for each side. Since this parts needs to be rotated each time (and assuming each of the six sides needs different milling processes) - how does the CAM software handle this situation ? Does it create six different programs as well ?

And the other basic question - related to the situation above - how does the CAM software know where your part is located on the table of the mill ? Is this a parameter that is entered ? Or what ?

Thanks.

[FranH]

Take a pin, chuck it, lower the spindle and move table until the fixed jaw of your vise rubs against a piece of paper between the pin and jaw. Lift the spindle out of the way and move the table one half the pin diameter. Establish zero in that plane. Do the same thing on the left end of the fixed jaw.

You can 'window' the part in the cam program and move it to x0 y0 by assigning the top left corner to be the x0 y0 position.

Now the x0y0 of the part is within .003 of being x0y0 of the vise (which is the machine 00).

[FranH]

MMMMM..... six sided part My cad/cam is decades old BUT it works by usage of layers. Layer zero is all the part geometry. With 254 layers (same as tracing paper over the original). Assuming there is no 4th axis (rotary table).

Place the part top left at XY00, program surface one. Make all those outlines, pockets, islands, toolpaths, to machine the part. Then make those layers inactive.

Place surface two top left at XY00, program surface two. If you used 10 layers to program surface one, they are now invisible. Your next outline, pocket etc will start on layer 11. Finish and machine and then make those layers inactive.

Do the same with the rest of the surfaces.

A 2 1/2 axis machine will stop after each cut and wait for you to do a tool change (or wait for you to rotate the part in the vise).

[Mike Stevenson]

Originally Posted by FranH Take a pin, chuck it, lower the spindle and move table until the fixed jaw of your vise rubs against a piece of paper between the pin and jaw. Lift the spindle out of the way and move the table one half the pin diameter. Establish zero in that plane. Do the same thing on the left end of the fixed jaw. You can 'window' the part in the cam program and move it to x0 y0 by assigning the top left corner to be the x0 y0 position. Now the x0y0 of the part is within .003 of being x0y0 of the vise (which is the machine 00).

WTF?

[DareBee]

Koch
I am quite sure you already know how to set up your machine considering you have been running mills for years and just hand coding.
All CAM will have different features and most Cam users will be able to do this in many different ways.
Initial part location is done by using a "set MCS" command which allows you to locate X0Y0 of your part (or stock block) with a few mouse clicks and maybe a number input. Then tell the Cam to output your FO number (G54, G55,...).

In the most basic software it is likely easiest to make separate programs. It is also possible to program the part as 4 or 5 axis and then hand code a M00 in between sequences to allow you to move the part. This can be dangerous because it requires the programmer to think a lot and add the right code in the right place (risk of error is high).
Cam will also allow you to flip/rotate the WCS between Mops which will work effectively the same as the 4/5axis scenario.

Maybe go to MecSoft.com and download their demo of VisualMill 6 and play with, it using the online tutorials.