PDA

View Full Version : mach 3 scaling issue



terry1956
14-09-2016, 04:55 PM
Hi chaps.i am having trouble scaling my work usinits far to mach3. I have used artcam 2017 to design the part and write the g code.checked the g code in cam editor and it looks ok, showing the correct tool path and measurements which are in MM.
Mach 3 is set up for MM. I have checked the measurements of the motor movements using the Mach 3 set up and they are correct in all axis.
But once the g code is loaded and starts to run, the machine makes the pattern far to large. Yet when I load the road runner test piece its far to small.
What am I doing wrong?????.

JAZZCNC
14-09-2016, 05:22 PM
Terry post the file as Txt file and I'll take a look.

The road runner is set for imperial units so it's correct that it would be small if using metric units. ie 1 inch would equal 1mm.
If you want to see the road runner cut correctly then type G20 in the MDI before running the code. Warning check the extents to make sure it will fit within your cutting area. Also Type G21 after it's cut to put you back in Metric.

Regards your G-code Did you use Post processor designed for Mach3.? And was it Metric.?

terry1956
14-09-2016, 08:00 PM
(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
14-09-2016, 08:19 PM
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
14-09-2016, 09:14 PM
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
14-09-2016, 09:45 PM
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.

19194

terry1956
14-09-2016, 10:34 PM
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
14-09-2016, 10:50 PM
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
14-09-2016, 10:57 PM
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.
19197

Neale
14-09-2016, 11:06 PM
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
14-09-2016, 11:27 PM
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
14-09-2016, 11:39 PM
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
15-09-2016, 08:53 AM
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.

Neale
15-09-2016, 09:08 AM
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.

Sorry - all bets off, then! Good chance that the 54mm/56mm means that steps per unit settings are wrong but this doesn't explain why the gcode doesn't do as expected. Let's see what a Mach3 reload does for things.

stirling
15-09-2016, 10:37 AM
Any chance you're using an "exotic" license?

terry1956
15-09-2016, 11:05 AM
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.

stirling
15-09-2016, 11:47 AM
OK - if you post your settings file here from your c:\mach3 folder. It's usually called Mach3Mill.xml

AndyGuid
15-09-2016, 12:45 PM
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.
@terry1956:
As an outsider looking in please would you mention whether you tried any of the previous well considered suggestions and/or the results of those suggestions, so we can all learn.
Thanks, Andy

terry1956
15-09-2016, 03:21 PM
Ok.update on this so far. The mach3 software is my own. The proxxon mill cuts to scale on all the test g codes to set up in mach3. The over upscaling comes into play when I used g code written by art cam express and used this program to post the g code in mach3 tap format. Using a cam edit software to view the g code turned up know errors.but mach 3 did not like the code and upscaled the work. To make sure it was not the mach software at fault I used an old test g code which resulted in the mill cutting the design correctly..at the moment it looks to me like the fault lays between the art cam way of writing g code and mach3 reading the art cam g code.
I am going to try a second program later today to write the g code.Will post how I get on later this week.

JAZZCNC
15-09-2016, 03:21 PM
Terry like Andy ask's did you try any of the suggestions and do the corrections.?

The G-code works fine so it's not the code. it's also very simple code nothing fancy.
There are very few settings in mach3 other than wrong steps per that will make it do what you describe. I've mentioned most of them.

terry1956
16-09-2016, 01:31 PM
I have done all the tests. On the machine coordinates test.the machine moved the correct distance. Using a demo from lazy cam the machine cut correctly. Any other g code it scales to large. Today I am going to reload mach3 on the machine pc. And try the tests again and try some project g code.