View Full Version : 4 axis rotary

05-09-2015, 01:46 PM
i dont think i got this in the right section ... please move if not

here goes ...

what im trying to understand on a rotary axis is how is the g code defined

for example , ive read (or watched you tube vids) that when using for example aspire vectric , that the x axis ( for example , could also be Y ) is unplugged and the rotary axis is plugged into this axis , so really the machine becomes a y and z linear machine and x rotary (so still a 3 axis machine not 4 ? )

but now if you had to use solidcam, camworks, etc then you could have a true 4 axis machine , so you could rough a piece of material lets say at 0 degrees, then rotate it 180 degrees and rough it again. Then do a finishing pass using the rotary axis ?

is that the way it works ?

05-09-2015, 09:09 PM
A proper cam program, depending on the post processor of course, will define the 4th axis as "A". So you have X, Y, Z, & A, and of course B, C if you have 6 axes.

Now the movement in "A" may be in mm or in degrees depending on your machine settings. There is a tick box in mach3 for that.

05-09-2015, 10:26 PM
If you're hand coding you need to start out understanding how the G-Code works, if you have a decent CAD/CAM package you just need to get the config right and the code comes out right.
There are so many ways to skin this cat, you can rough and finish a 4-Axis job in 3 Axes with manual 90 degree indexing, without using a 4th.

- Nick

06-09-2015, 09:17 AM
As the guys said, you'll have an x,y,z and a axis. Best bet is to do all the roughing in 3 axis mode and just index 90 degrees each time, then do your finishing in 4 axis mode to optimise the surface finish. Solidcam has some nice features where you can finish parallel to a curve or to an axis or you can let your toolpath morph from the shape that defines one side of a face to that or the other. So if one end of the face was an arc and the other a straight line, your toolpath woud start as an arc and gradually change as it machines the face to straight lines. Nifty stuff.