mach 3 scaling issue

[terry1956]

Just completed the test.the tool pointer moved 56mm, so a little bit of adjustment needed.but this does not answer why the machine is cutting far to large.the fault must lay in the way mach 3 is reading the artcam software.could it be that the g code needs to be in a different format .....

[JAZZCNC]

Terry the code is fine I loaded it into mach it cut air perfectly.

I wouldn't mess around just install mach again. Then try but first make sure the steps per setting is correct. This figure isn't just some randon number or one that can be close. It must be exact or the machine will never move correct distance.

[JAZZCNC]

There is one thing you could try but I don't think it will be the problem but hurts nothing to try.
The code uses IJ mode for the arc moves so could try changing the IJ Mode setting in general config. However usually when the IJ mode is wrong you'll get large circles on the screen.

Go to General Config change the IJ Mode to opposite of what it's set to now. See pic where to find.

[Neale]

I was looking at Terry1956's machine earlier this week. It's a Sieg X1 and appears to have 3mm pitch trapezoidal leadscrews. Drivers are set to 1600 microsteps/rev, and Mach3 was configured with 533.333 steps/per. System set to mm, of course. We didn't actually measure movement at the time. I would double-check that the steps/per figure is still set OK, just in case something has changed there. Certainly not obvious why that gcode shouldn't run just fine, though.

[JAZZCNC]

It's a Sieg X1 and appears to have 3mm pitch trapezoidal leadscrews.

Did you actually check the movement.? Could it be multi start lead screw.?

[Neale]

Didn't appear to be multi-start. I quickly checked pitch with a caliper, mainly to make sure that it was 3mm and not 8tpi, bit it's not the most accurate measurement to do. The x54 move giving about 56mm movement is slightly odd as that doesn't tie up with either pitch. Unless steps per has got itself changed. The current motor mounts are a bit crude (plan is to remake) but I can't see how any flexibility in that or missed steps would give too much movement. X and y axes seem to move smoothly enough. Should have done a bit more testing...

[terry1956]

hi, this is on the proxxon mill, not the sieg mill. I was hoping to make the mounting plates on the proxxon. will reload mach3 today, and see what happens.

[terry1956]

hi. just an update. I made a small demo shape using lazy cam and then used this on the proxxon. the machine cut the shape. so it must be a fault in the way the artcam g code is being read by Mach3, and not the machine itself or the way Mach3 is set up on the machine.
anyone any ideas on this.