Finished my build, but 1st test plot went horribly wrong.

[pmowry911]

Well, maybe not horribly but the sounds still scared the hell out of me.  Reminded me of my first RC airplane crashing into the ground only recovering the engine. 

The build was fun and I spread it out over the week due to work.  This gave the cat time to run off with the m3 washers and nuts so just needed a quick trip to lowes when I was putting the control box together =)

 To test alignment I used Inkscape  just to put text and shapes in a box on letter sized page.  I used its Gcodetools -> Engraving extension with my Z-depth set to 0 and a G00 Height of 5 hoping to make it act like a plotter.  But I should have looked at the code since the 1st think it did was smash the pen into the table.  removing the pen and setting Z-zero up an inch or two on the machine I see a lot of unnecessary z movement, and kinda musical sounds while doing so.  I took a video, but don't want to post it to social media as get my family's attention just yet and figured it was too big(83mb) to post here .  Some of the code from the start looks like this: 


M3

G21 (All units in mm)


G00 Z5.000000

G00 X146.929829 Y66.147077



G01 Z-4.999990 F100.0(Penetrate)

G01 X139.355859 Y62.362957 Z-4.999990 F400.000000

G01 X139.069488 Y62.219898 Z-4.999990

G01 X132.241263 Y53.219069 Z0.000000

G01 X139.069488 Y62.219898 Z-4.999990
....
G01 X146.929829 Y66.147077 Z-4.999990

G00 Z5.000000



G00 Z5.000000

G00 X135.595163 Y35.923193



G01 Z-0.033980 F100.0(Penetrate)

G01 X134.613679 Y34.512082 Z-1.015492 F400.000000

G01 X134.613679 Y28.867638 Z-1.015492

G01 X134.613679 Y27.456527 Z-1.015492

G01 X134.613679 Y26.045415 Z-1.015492

G01 X134.613679 Y25.615817 Z-1.015492
...

Anyone using Inkscape with suggestions on what I did wrong? I converted text, spiral, circle, square and star shapes to paths.  It tries to do the star first 

In the short term can I just change all the negative Z values to 0 and expect a good run?  My only positive Z is the G00 Z5 lines.  Most of the negatives are between 0 and -1.1 but it does go to -4.999 in several places.

Thank you,

[Derek the Admin]

Z-4.99999 means that it's plunging 5 mm into the stock. If you zerod the pen to the top of the stock then it was trying to drive down below that. The unnecessary Z movement that you refer to is the machine following the instructions in the code you posted. It is being commanded up and down several times. Take a screenshot of what your inkscape setup looks like and post it please.

The musical noise that you describe is normal and just the noise of stepper pulses. I've actually used the M3 and a "song generator" in a CNC program to play songs in the style of old cellphone ringtones.

[pmowry911]

Jul 25, 2017 17:28:44 GMT Derek the Admin said:

 Take a screenshot of what your inkscape setup looks like and post it please.

The musical noise that you describe is normal and just the noise of stepper pulses. I've actually used the M3 and a "song generator" in a CNC program to play songs in the style of old cellphone ringtones.

It sounded like the theme from Castlevania on the NES =)  I just can't figure out why Inkscape decided it needed a bunch of little up and down movements in steps like this
G01 X126.869953 Y26.694978 Z-1.113508

G01 X126.638559 Y27.352528 Z-1.099538

G01 X126.563234 Y28.585895 Z-1.024213

G01 X126.558633 Y28.743770 Z-1.019612

Inkscape is ver .91, but I don't think the extension has been updated in a while.  I'll upgrade to .92.1 anyway.  Here is a screenshot of my test image and gcodetools settings.  The engraving options tab was defaults (scale along z: 1,Offset along Z: 0, minimum arc radius: 0.05000)




Maybe I confused it when I set the Z depth to 0.  I used the engraving instead of path to gcode thinking engraving would only scratch the surface.

Edit:  Oh, and just for reference the machine is working great.  Nice and clean until I run it in to something.  I'm sure the file in the Quickstart guide will complete with no problems but I did not have any scrap wood around.  Hence trying to make it into a plotter.  Looking at the Inkscape tutorial in Resources I see you using 2 points mode on the Orientation point page where  i used 3.  I'll try it again with that setting when I can.

[aforww]

Your other option, use an option to remove all Z commands. Derek could probably point you there. I don't remember the website. Basically, you upload your gcode and it spits it back out with all Z movements at zero.

[Derek the Admin]

Laseroko app is what that's called. You can google it. Be advised that it will place a couple things in the header than you don't want (I think some low feed rate command if I remember right).

I'll look back at your settings when I get a chance.

[Derek the Admin]

Jul 25, 2017 18:41:35 GMT pmowry911 said:

Jul 25, 2017 17:28:44 GMT Derek the Admin said:

 Take a screenshot of what your inkscape setup looks like and post it please.

The musical noise that you describe is normal and just the noise of stepper pulses. I've actually used the M3 and a "song generator" in a CNC program to play songs in the style of old cellphone ringtones.

It sounded like the theme from Castlevania on the NES =)  I just can't figure out why Inkscape decided it needed a bunch of little up and down movements in steps like this
G01 X126.869953 Y26.694978 Z-1.113508

G01 X126.638559 Y27.352528 Z-1.099538

G01 X126.563234 Y28.585895 Z-1.024213

G01 X126.558633 Y28.743770 Z-1.019612

Inkscape is ver .91, but I don't think the extension has been updated in a while.  I'll upgrade to .92.1 anyway.  Here is a screenshot of my test image and gcodetools settings.  The engraving options tab was defaults (scale along z: 1,Offset along Z: 0, minimum arc radius: 0.05000)


View Attachment

Maybe I confused it when I set the Z depth to 0.  I used the engraving instead of path to gcode thinking engraving would only scratch the surface.

Edit:  Oh, and just for reference the machine is working great.  Nice and clean until I run it in to something.  I'm sure the file in the Quickstart guide will complete with no problems but I did not have any scrap wood around.  Hence trying to make it into a plotter.  Looking at the Inkscape tutorial in Resources I see you using 2 points mode on the Orientation point page where  i used 3.  I'll try it again with that setting when I can.

Glad the machine is running well. I was just about to commend that I see that the orientation points in your workspace show a -6.## as the z bottom. That may be part of the problem. I never used the engraving feature. I always used path to g code. I've found inkscape's gcodetools to be a little cryptic sometimes on any feature except the "path to gcode." I personally got my start using gcodetools, but it's my recommendation that you move beyond it quickly to a more refined CAM package. I still use inkscape for some design, but usually export it to do my CAM work in fusion or other programs.

[pmowry911]

Thanks for the help,  and yes I need to move on to better software that will protect me from myself.  I used the the Laseroko app to zero out the negative Z points and then did a search/replace to change the laser off to G00 Z5 and then G01 Z0 after the move.

That worked great and it ran again just fine until it hit the 1st of two lines with Y-231.872 and it tried to run off the end.  Did not think to check the other axis for neg values or positive to large.



Are their pins where I can add contacts to keep it from trying to run off either end, or a way to create a bounding box in grbl so it halts on invalid commands to protect itself?  Or is there another app to test movements stay within a box before sending it to the machine?  I have Inkscape and blender already running on this PC was the only reason I used them.  The picture is a little warped but the test accomplished what I wanted.  No text written backwards and everything looked straight.  The reason some things are missing from the top is the that strip was actually pushed down into the t rail just a bit when I taped down the corners.  Since my pin was just touching at the bottom left to start with contact disappearing at the rail gives me confidence at least the x/y plane is aligned with the bed.

[aforww]

You can setup soft limits in GRBL to keep from going beyond it's limits. I use them. However, it can cause you some problems. When you hit a soft limit using UGS it locks it yup. You can't soft reset. So you end up having to reset everything thus losing all your WCS zero. That translates into a lost project if it hits them.

What I have made a habit of doing is checking travel before I hit go. In UGS-p you can right click in the visualizer and send your machine to any position you want. For projects are closer to the edge, I'll check that it's in my work area my sending the spindle to the farthest extents.