Path : am I doing it wrong ? Is my object too complex ?

[berdeter]

Hi all,

I found Marz plugin the fretboard and it helped a lot. I'm trying to prepare the production on a chinese 3040T. I have to print in 2 passes because fretboard is too long for the CNC. I divided it in 2 parts for that.

I'm trying to find my way into the procedure. I coud find some solutions but :

- the top face is not actually flat. I' could set a mill face but I fear it could not do the job
- i could find no tool accepting to do the sides (should not cut the thing in 2 !
- For the fret slots that should be 0.7mm wide I plan to use e 0.7mm endmill. Seems to do nothing. Do I need a 0.5 ? Quite fragile beast.

I've tried with both 0.18 and 0.19 with no real success.

Bugs ? Too complex for current FreeCad ? Bad manupulation ?

Can anybody help ?

Great thanks for this fantastic software and for your help.

Bernard

[GeneFC]

This looks pretty difficult, but here are a couple of hints.

Tools must be able to fit in the space to be pocketed. Simply declare that your 0.7 mm tool is a tiny bit smaller than 0.7 mm.

Pocket_Shape will only work with pockets that have flat faces on the bottom. You will need to use Pocket_3D for cutting the frets.

I did a very simple test on a single fret groove, using the hints above, and it seemed to work.

Good luck!

[Edit: The file you posted was made with FC 0.18. FC 0.19 is much, much more capable with 3D operations.]

Gene

[berdeter]

This looks pretty difficult, but here are a couple of hints.

Tools must be able to fit in the space to be pocketed. Simply declare that your 0.7 mm tool is a tiny bit smaller than 0.7 mm.

Pocket_Shape will only work with pockets that have flat faces on the bottom. You will need to use Pocket_3D for cutting the frets.

I did a very simple test on a single fret groove, using the hints above, and it seemed to work.

Good luck!

[Edit: The file you posted was made with FC 0.18. FC 0.19 is much, much more capable with 3D operations.]

Gene

Great hint thank you. Indeeed the tool has to be smaller than the pocket. So I'll buy a 0.6mm tool for my 0.7mm pockets.

The file was actually made from 0.19 but I had done several tries with both 0.18 and 0.19 to see if one of both versions would do beter.

I still have a problem for the other operation. I would like to contour the fretboard but only on lateral faces, not all around. Contouring all around would cut it in 2 pieces. I found no tool in the Path worbench that accepted to do so. I've just tried it again on a simple block. Trying to create a "Profile entire model, selected faces or selected edges" on a side face I get the folloging exception :

15:59:45 Path workbench activated
16:00:15 centroid_post gcode postprocessor loaded.
16:00:15 centroid_post gcode postprocessor loaded.
16:00:22 centroid_post gcode postprocessor loaded.
16:00:32 Profiling Select Mode
16:00:53 <Path.Area> Area.cpp(1318): project failed
16:00:53 <Path.Area> Area.cpp(1460): empty projection
16:00:53 Traceback (most recent call last):
File "D:\Apps\FreeCAD_0.19.22522-Win-Conda_vc14.x-x86_64\Mod\Path\PathScripts\PathUtils.py", line 62, in new_function
res = function(*args, **kwargs)
File "D:\Apps\FreeCAD_0.19.22522-Win-Conda_vc14.x-x86_64\Mod\Path\PathScripts\PathOp.py", line 515, in execute
result = self.opExecute(obj) # pylint: disable=assignment-from-no-return
File "D:\Apps\FreeCAD_0.19.22522-Win-Conda_vc14.x-x86_64\Mod\Path\PathScripts\PathAreaOp.py", line 401, in opExecute
aOS = self.areaOpShapes(obj) # pylint: disable=assignment-from-no-return
File "D:\Apps\FreeCAD_0.19.22522-Win-Conda_vc14.x-x86_64\Mod\Path\PathScripts\PathProfile.py", line 495, in areaOpShapes
shapeEnv = PathUtils.getEnvelope(shape, depthparams=custDepthparams)
File "D:\Apps\FreeCAD_0.19.22522-Win-Conda_vc14.x-x86_64\Mod\Path\PathScripts\PathUtils.py", line 316, in getEnvelope
sec = area.makeSections(heights=[0.0], project=True)[0].getShape()
<class 'IndexError'>: list index out of range

I've tried all the tools but none can do it.

If I select the top face it goes all around.

See my new attachement JobTest.FCStd

[GeneFC]

Indeeed the tool has to be smaller than the pocket. So I'll buy a 0.6mm tool for my 0.7mm pockets.

The file was actually made from 0.19 but I had done several tries with both 0.18 and 0.19 to see if one of both versions would do better.

I did not say the tool needs to physically be smaller. You just need to fool FreeCAD by entering a slightly smaller size. In this case I would tell FreeCAD that the tool size is 0.699 mm and then go ahead and use your 0.7 mm tool for the actual cutting. Of course you can use a smaller tool if you wish.

The file you posted was definitely made with 0.18. That information is contained directly inside the file.

First file posted:

<Document SchemaVersion="4" ProgramVersion="0.18R4 (GitTag)" FileVersion="1">

Latest file posted:

<Document SchemaVersion="4" ProgramVersion="0.19R22522 (Git)" FileVersion="1">

Gene

[berdeter]

Indeeed the tool has to be smaller than the pocket. So I'll buy a 0.6mm tool for my 0.7mm pockets.

The file was actually made from 0.19 but I had done several tries with both 0.18 and 0.19 to see if one of both versions would do better.

I did not say the tool needs to physically be smaller. You just need to fool FreeCAD by entering a slightly smaller size. In this case I would tell FreeCAD that the tool size is 0.699 mm and then go ahead and use your 0.7 mm tool for the actual cutting. Of course you can use a smaller tool if you wish.

The file you posted was definitely made with 0.18. That information is contained directly inside the file.

First file posted:

<Document SchemaVersion="4" ProgramVersion="0.18R4 (GitTag)" FileVersion="1">

Latest file posted:

<Document SchemaVersion="4" ProgramVersion="0.19R22522 (Git)" FileVersion="1">

Gene

Thank you Gene. Again I'm new to CAM and new to FreeCAD. I'm tryiong to find my way.

Any idea for the other problem ? I'm trying to contour the fretboard but not all around, just 2 faces. I had the idea that I could just extend the fretboad by a plate that I'd separate by a grove and do a pocket operation in that grove. Maybe that pocket operation can be a 3D pocket that includes the top of the fretboard that is not flat.

I'll try that this WE...

[berdeter]

I've tryied enclosing the fretboard so cutting lateral faces would actually be equivalent to making a grove.

Can't find any way to let the job cut it either... See attached file.

[GeneFC]

Your file has a problem with circular dependencies. It cannot be used further without correcting the dependency errors.

Capture.PNG (66.98 KiB) Viewed 183 times

Those red arrows show the circular dependencies. For example. "Slice" is dependent on "BaseFeature", and if you follow the arrows you will see that "BaseFeature" is dependent on "Slice".

You may need to go back and get a better understanding of how to build a robust model.

Gene

[berdeter]

Your file has a problem with circular dependencies. It cannot be used further without correcting the dependency errors.


Capture.PNG


Those red arrows show the circular dependencies. For example. "Slice" is dependent on "BaseFeature", and if you follow the arrows you will see that "BaseFeature" is dependent on "Slice".

You may need to go back and get a better understanding of how to build a robust model.

Gene

Thank you Gene for that graph. Can it be done from FreeCAD to check on the problem ?

I understand my trial and errors caused that. I'll keep that in mind. It would be great to have access to that graph as a function in the product so that you can understand what's wrong.

Bernard

[kisolre]

Can it be done from FreeCAD to check on the problem ?

Std_DependencyGraph