Does anybody use the Mach3 control software? If so, do my soft limits work on machine or work coordinates?
I don’t know Mach 3. I, however, would imagine soft limits should work all the time. Given that they are soft, your steppers might lose steps and their your limits out of whack from time to time.
Hm. Might need to do some more investigation on that. If there go by work coordinates and I use an offset than my soft limits will be different all the time and/or out of limit switches. It need to hit the soft limit before the limit switch gets hit. So it would make sense to me if they are going by machine coordinates but I’m just not sure one it. Well I suppose a couple trails and a play with the settings might show me more.
@Sandro_Kuehne
a machine can use more than one set of coordinates at a time. Computers have a knack with numbers. But soft limits do rely on you homing your machine properly before operation. Although software can remember coordinates between sessions too.
I do know all that. I just thought that would be a straight forward answer but officially it’s not. I do home my machine into the far right hand corner on XYZ-0 and than apply an offset so that XYZ-0 goes to my front left corner. The only reason for that is so that I don’t have to add a minus into my g-code. I just find it easier to program into the plus. But when it comes down to my soft limits they need to stay on machine coordinates so the XYZ is still in the far right corner. This way I can apply any offset I like but my soft limits will stay where they are. So regardless on my offsets the soft limits should not allow me to go past my set machine coordinates. But that of course only works if they do use machine coordinates. I hope that makes it a bit more clearer.
@Sandro_Kuehne
because of some demo code I started homing my machine in the middle. It had negative coordinates in the code, so I set my machine up positive, and negative, so I could run that demo. It kind of limits my travel in the positive direction. But at the same time I like working in the middle of the machine too. So I don’t know how to feel about it all right now.
One thing someone taught me was you can touch off all axis. X, Y, and Z. Which can change the relative offsets. I don’t know why that never dawned on me, but it didn’t.
Homing the machine in the centre of the bed? Hm, never thought about that. I can see that working if you can somehow locate you work piece in the same position all time. For now I probably will carry on the way how I set up my bed. And for the soft limits I probably have to run some demo codes to find out on what coordinates they are based on.
This is the screen for setting limit
missing/deleted image from Google+
@Sandro_Kuehne
I mainly do decorative engraving so close enough is close enough. I do usually fly over the work piece and watch the tool path on the screen. Just to make sure my pattern is going to go where I want it to. But if I needed more accuracy than that I could just step off the work piece with an offset.
Like any milling job is setup. I usually work in about the middle of a mill table. So a CNC machine is about the same.
I didn’t have a home switch when I was using Mach3. And the soft limits never did work… thinking about it now that’s probably why it never really work. I switched to PathPilot from Tormach now …