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How to avoid CNC crashes Answered

Hey.

I am wondering if it is possible to define particular areas on the bed of my CNC machine which I do not want the toolhead to pass over.

My setup is an Arduino powered CNC pen plotter running GRBL. I am generating GCode in inkscape.

I know I can set a safe height for the tool to pass over work safely but what if that height doesn't suffice. Can I define an area that the tool must not pass through?

As a simple example:

Before running a file the tool is at the origin. On sending the file the tool will take the most direct path to the first line to cut/draw. Imagine there is an obstacle that would cause a collision if the tool takes this direct path. Can I do something to ensure the tool navigates around that obstacle?

I hope that makes some sort of sense :)

Any ideas appreciated

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steveastrouk

9 months ago

Its always a problem, I use $6000 CAM software to generate tool-paths - and its possible to create exclusion areas in THAT, but not in hand-crafted Gcode.

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Henri.Lacostesteveastrouk

Reply 9 months ago

I have had a play on RhinoCAM, from what I understand is very similar to VisualMill, and have found avoid areas. I'm not sure they are able to do what I want them to. When I add an avoid area all that seems to happen is that the clearance height increases to avoid the region, is there a way to navigate around the region instead. My gantry has a greater clearance than my tool, so it would be good to be able to generate gcode that moves around obstacles, rather than over them. Is there a way to do this in VisualMill/RhinoCAM?

I'm not able to add an image here for some reason so here is a link to a render that might aid my explanation: https://postimg.org/image/clnmh0oed/

Thanks for your help :)

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Henri.Lacostesteveastrouk

Reply 9 months ago

Thanks, I just had a look on MechSoft's website and I can demo their software. Can you give me any clues as to how I can setup these exclusion zones? Any videos or sources that may help?

Will VisualCAM/VisualMill be suitable for creating a Gcode file from a vector line drawing such as a .dxf .dwg .svg file?

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steveastroukHenri.Lacoste

Reply 9 months ago

If you use the Artcam extension, I think so. Their non-paid for programming is pretty limited sadly.

If you create a polyline surrounding the area you want to exclude, and surround it with a polyline where you want to work, when you select the machining operation, and click the two polylines, it should automatically exclude the area you have walled off.

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Henri.Lacostesteveastrouk

Reply 9 months ago

Thanks for you reply. I think for now the only way I can think might work is to generate seperate Gcode files for areas I want to work in and join them with a piece of Gcode that navigates a safe path between.

Not sure if that is going to work though!

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bluehawk6465

9 months ago

I have four CNC machines and only one works. They have been in and out of the repair shop

more than I care to think. Fantastic when they work. Good luck.