mach 3 scaling issue

[terry1956]

(motormouting inside motor hole profile 4 hole g code)(Material Size) (X=55.000, Y=55.000, Z=0.000)
(Tool Number:1) (3.000 mm dia. slot drill)
G017 G21 G49 G80 G90 G91.1
G0Z5.0000
M3 S15000
G0 X4.4000 Y26.6000 Z3.0000
G1 Z-1.6667 F240
G3 X28.4000 Y2.6000 I24.0000 J0.0000 F600
G3 X52.4000 Y26.6000 I0.0000 J24.0000
G3 X28.4000 Y50.6000 I-24.0000 J-0.0000
G3 X4.4000 Y26.6000 I0.0000 J-24.0000
G1 Z-3.3333 F240
G3 X28.4000 Y2.6000 I24.0000 J0.0000 F600
G3 X52.4000 Y26.6000 I0.0000 J24.0000
G3 X28.4000 Y50.6000 I-24.0000 J-0.0000
G3 X4.4000 Y26.6000 I0.0000 J-24.0000
G1 Z-5.0000 F240
G3 X28.4000 Y2.6000 I24.0000 J0.0000 F600
G3 X52.4000 Y26.6000 I0.0000 J24.0000
G3 X28.4000 Y50.6000 I-24.0000 J-0.0000
G3 X4.4000 Y26.6000 I0.0000 J-24.0000
G0 Z3.0000
G0 X1.5000 Y6.9641
G1 Z-1.6667 F240
G1 Y48.0359 F600
G3 X6.3284 Y48.6716 I2.0000 J3.4641
G3 X6.9641 Y53.5000 I-2.8284 J2.8284
G1 X48.0359
G3 X48.6716 Y48.6716 I3.4641 J-2.0000
G3 X53.5000 Y48.0359 I2.8284 J2.8284
G1 Y6.9641
G3 X48.6716 Y6.3284 I-2.0000 J-3.4641
G3 X48.0359 Y1.5000 I2.8284 J-2.8284
G1 X6.9641 Y1.5000
G3 X6.3284 Y6.3284 I-3.4641 J2.0000
G3 X1.5000 Y6.9641 I-2.8284 J-2.8284
G1 Z-3.3333 F240
G1 Y48.0359 F600
G3 X6.3284 Y48.6716 I2.0000 J3.4641
G3 X6.9641 Y53.5000 I-2.8284 J2.8284
G1 X48.0359
G3 X48.6716 Y48.6716 I3.4641 J-2.0000
G3 X53.5000 Y48.0359 I2.8284 J2.8284
G1 Y6.9641
G3 X48.6716 Y6.3284 I-2.0000 J-3.4641
G3 X48.0359 Y1.5000 I2.8284 J-2.8284
G1 X6.9641 Y1.5000
G3 X6.3284 Y6.3284 I-3.4641 J2.0000
G3 X1.5000 Y6.9641 I-2.8284 J-2.8284
G1 Z-5.0000 F240
G1 Y48.0359 F600
G3 X6.3284 Y48.6716 I2.0000 J3.4641
G3 X6.9641 Y53.5000 I-2.8284 J2.8284
G1 X48.0359
G3 X48.6716 Y48.6716 I3.4641 J-2.0000
G3 X53.5000 Y48.0359 I2.8284 J2.8284
G1 Y6.9641
G3 X48.6716 Y6.3284 I-2.0000 J-3.4641
G3 X48.0359 Y1.5000 I2.8284 J-2.8284
G1 X6.9641 Y1.5000
G3 X6.3284 Y6.3284 I-3.4641 J2.0000
G3 X1.5000 Y6.9641 I-2.8284 J-2.8284
G0 Z3.0000
G0 X0.0000 Y0.0000 Z5.0000
G0Z5.0000
G0X0.0000Y0.0000
M5
M30




this is the g code I used. it looked ok on CAMotics, but Mach 3 made it far to big. whats wrong ?????

[JAZZCNC]

Can't see anything wrong there and it loads into mach fine here. Roughly 54mm square.

If you can't find any obvious reason ie Step per Settings etc then I'd install Mach3 again seen daft things like this happen before. just install over top of existing setup all settings will be retained.

Sure this won't be the case but you haven't set scale factor have you.? If you have the scale LED's will be flashing at you so will be obvious.

[terry1956]

Hi.i am looking at the mach3 manual, but it as nothing on scale. In what position are the scale factor leds. Apart from looking at the scale factors, and reloading mach, is there anything else I need to look at. As stated the tool moves correctly when setting the auto measurements of axis. Thanks for helping.

[JAZZCNC]

See pic for scaling location.

To test if moving correct distance use the MDI and command a move. Try this.
First Zero the axis you wish to move. In this case lets say X axis. Type these commands in order written below push enter after each.

G21
G90
G1 X54 F500

If it doesn't move correct distance then it can only be that your Steps per are not set correctly.

It's very easy to calculate the steps per. Take the micro step setting on the drive and divide by the pitch of the ballscrew. If uses ratio this will need be taken into account.

[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.