Problem during a 2.5D job

Chrisprols
Posts: 38
Joined: Thu Mar 27, 2014 7:48 am

Problem during a 2.5D job

Post by Chrisprols » Tue Jul 28, 2015 2:19 pm

Hi,


I'm posting this message in this section, but if it belongs to another one, please move it !

The problem is the following : during a pocket operation, my spindle went completely out of track ... going much further than the pocket limits and pushing the boundaries of my shapeoko 2 ... well that didn't go well.


My problem now is that I reproduced the issue. I re-zeroed my cnc, zeroed the Z axis and ran the g-code again ... and the same problem happened.
... but ... I don't understand what is wrong.

no missed steps, that wouldn't make the spindle go further than it should in the x (or y) direction.
no "not understood code" on the g-code sender.
no crazy coordinates in the g-code (... maybe I'm wrong ?)

The machine is fine, the code looks ok (but I'm absolutely no expert), the design went ok (inkscape), the CAM went ok (Cambam), the g-code sender should be ok (simulation looks good), the arduino uno is ok (grbl 0.9 running correctly).
img01 (Large).jpg
img01 (Large).jpg (256.05 KiB) Viewed 2076 times
Maybe some incompatibility at the header ?
img02 (Large).jpg
img02 (Large).jpg (252.45 KiB) Viewed 2076 times
if you might need the original g-code, I attached it as well :
pince crimping & ferrules.nc
(450.64 KiB) Downloaded 36 times


If you have any idea ? ... idea of solution or what I should troubleshoot ...
Shapeoko 2 #4852 with Bosch Colt
Location : Rouen, FRANCE

Chrisprols
Posts: 38
Joined: Thu Mar 27, 2014 7:48 am

Re: Problem during a 2.5D job

Post by Chrisprols » Tue Jul 28, 2015 2:23 pm

oh and just an additionnal image of the catastrophy :
IMG_20150728_155840 (Small).jpg
IMG_20150728_155840 (Small).jpg (36.41 KiB) Viewed 2076 times

FYI, I'm milling some pockets in foam to the shape of some hand tools. Those pieces of foam will go in the drawers of my toolbox.
I'm aiming for something like this :
http://foamfittools.com/graphics2/F1S-0 ... ches_1.jpg
Shapeoko 2 #4852 with Bosch Colt
Location : Rouen, FRANCE

WillAdams
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Location: Pennsylvania --- south of the Turnpike, East of US-15
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Re: Problem during a 2.5D job

Post by WillAdams » Tue Jul 28, 2015 2:32 pm

Anyway to get Cambam to not emit the Tooling commands which aren't supported by Grbl?

Code: Select all

T0 M6
Verify your G-codes against the ones noted as supported by Grbl? http://www.shapeoko.com/wiki/index.php/G-Code
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

Chrisprols
Posts: 38
Joined: Thu Mar 27, 2014 7:48 am

Re: Problem during a 2.5D job

Post by Chrisprols » Tue Jul 28, 2015 2:48 pm

Thanks for your answer and advise.
I didn't check my code against the wiki page ... I didn't know how to do it.
... so for this time, I only looked by hand (if there is any automated way, I'd be happy to know) even though I'm not sure what I should be looking at.

The only discrepency I can see is G64 in the first lines (path control mode = constant velocity mode ... ?)
Then the tool change you spotted TO M6.
And the spindle spindle direction and speed which I can't see if there are supported or not (M3 S1000).

I didn't see some other potential problem (but my eyes are blurry from all those g-code lines)
I don't see why the simulation from g-sender went ok and then the job went banana.
I don't see why those particular command would push my spindle till some crazy coordinates (X6200 and Y6500 ...)

I will look in CAMBAM can be customised to include only GRBL g-code.

EDIT : I can see on google some posts on cambam forum about its post-processor and compatibiliy with GRBL and arc questions ... I would beleive since grbl 0.9 this is not the issue, but I'm going to try my code again with isung only (tiny) lines instead of arcs. We'll see it that does it better.
Shapeoko 2 #4852 with Bosch Colt
Location : Rouen, FRANCE

RobCee
Posts: 587
Joined: Wed Jan 08, 2014 11:33 am
Location: Birmingham, UK

Re: Problem during a 2.5D job

Post by RobCee » Tue Jul 28, 2015 5:07 pm

I think that the behaviour you are describing (other than the display of coordinates) really sounds like missed steps - your spindle is not where it thinks it is, so it is moving more/less than you expect in one direction.
Your gcode looks ok, although removing the G64 from the CamBam postprocessor setup will help, as grbl is currently ignoring that entire line. The tool change lines can be ignored safely as they do nothing with grbl.
I would check the temperature/current of your stepper drivers and see if you can eliminate the possibility of thermal shutdown. Are you cooling your board?
ShapeOko2 #3400 - Chinese 800W AC Spindle - Stiffened X-Axis - TR10 Z-Axis - Inverted Z Motor - Hall Effect Limits - Drag Chains & Custom Brackets

Chrisprols
Posts: 38
Joined: Thu Mar 27, 2014 7:48 am

Re: Problem during a 2.5D job

Post by Chrisprols » Tue Jul 28, 2015 5:36 pm

Hi again,


No mean to contradict you, RobCee, but I'm milling foam. Ok it's a hard foam rather than the usual foam you can find in a basic cusson/pillow but it's really easy to mill.

In the meanwhile I have gone back in my workshop and re-generated the code with a change in CAMBAM settings : I asked the software to convert any arc in a serie of tiny lines (each being straight).

For those wondering, it's in the post processor thing. Right below the "styles", you have the post processor and I edited the default to put the "Option" > "Arc output" set to : "convert to lines"
I checked the length value and it was 0.01 ... ok fair enough to me.

http://www.cambam.info/doc/plus/cam/PostProcessor.htm

Then I re-generated the code. It more than doubled the size and quadruppled the lines.
Half a mega to more than a megabite.
12k lines to 44k lines.
........... But ..... it all went fine. I sent the file to the usual g-code sender and it all went good :
IMG_20150728_182631 (Medium).jpg
IMG_20150728_182631 (Medium).jpg (64.85 KiB) Viewed 2056 times


However I join you in the idea that the line being completely ignored because of G64 is maybe a problem.
I'd have to check, to be proactive ... but my CNC time is very limited. For now I'll stick to the arc-to-line conversion.
Shapeoko 2 #4852 with Bosch Colt
Location : Rouen, FRANCE

RobCee
Posts: 587
Joined: Wed Jan 08, 2014 11:33 am
Location: Birmingham, UK

Re: Problem during a 2.5D job

Post by RobCee » Tue Jul 28, 2015 5:47 pm

Hi Chrisprols, I am always happy to be wrong and it sounds like you have found a working solution, which is great.
ShapeOko2 #3400 - Chinese 800W AC Spindle - Stiffened X-Axis - TR10 Z-Axis - Inverted Z Motor - Hall Effect Limits - Drag Chains & Custom Brackets

Chrisprols
Posts: 38
Joined: Thu Mar 27, 2014 7:48 am

Re: Problem during a 2.5D job

Post by Chrisprols » Tue Jul 28, 2015 6:07 pm

hey

yes I guess it's more related to arcs and lines and how grbl handles them and how cambam produce them ... maybe
Shapeoko 2 #4852 with Bosch Colt
Location : Rouen, FRANCE

RobCee
Posts: 587
Joined: Wed Jan 08, 2014 11:33 am
Location: Birmingham, UK

Re: Problem during a 2.5D job

Post by RobCee » Tue Jul 28, 2015 7:57 pm

I still think that your issue sounds like missing steps. Not due to the difficulty of cutting, but to do with the rapid movements of the axes associated with the arcs. I would still check out the temperature of your stepper drivers if you can. They get very hot when holding or moving the motors, particularly if there are many small adjustments in a short time.
I have used CamBam with grblShield and UGS for 18 months and had no issues with them working together nicely, after initial setup.
I did however, run into a Z-Axis issue of lost steps when I tried to do some 3D Carving (using VCarve Pro), which required a lot of small Z-Axis movements. I suspect overheating and have ordered some heat sinks to help with the problem.
ShapeOko2 #3400 - Chinese 800W AC Spindle - Stiffened X-Axis - TR10 Z-Axis - Inverted Z Motor - Hall Effect Limits - Drag Chains & Custom Brackets

rodcar125
Posts: 67
Joined: Fri Feb 06, 2015 5:00 pm

Re: Problem during a 2.5D job

Post by rodcar125 » Wed Jul 29, 2015 1:18 pm

I think is the line where you get the first error.
When GRBL runs into a command that it is not known/supported, the whole line is ignored so in your case, the G21 G90 and G40 are ignored meaning that mm mode and your absolute coordinates are not being applied. If you have your machine set up in inches at boot up, that may be the problem. I would suggest to delete G64 and any other commands that are not supported when they come in the same line with other commands.
In the case of the T0M6, its also ignored but since its alone in a single row with no other commands it has no relevance to the program.

You can do a semiautomatic tool change using chilipeppr.com/grbl since its the GUI who detects the M6 command and not grbl

Hope this helps and let me know how it went

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