Getting started with Path in v0.17

Here's the place for discussion related to CAM/CNC and the development of the Path module.
GeneFC
Posts: 67
Joined: Sat Mar 19, 2016 3:36 pm
Location: Punta Gorda, FL

Re: Getting started with Path in v0.17

Postby GeneFC » Tue Dec 13, 2016 12:53 am

I am not suggesting mixing units. I have merely observed that almost all quantities in FreeCAD are shown with units attached to the number. There does not appear to be a good reason to strip the units from quantities displayed in the Path Workbench.

Gene
jcf
Posts: 35
Joined: Tue Nov 15, 2016 10:34 am

Re: Getting started with Path in v0.17

Postby jcf » Tue Dec 13, 2016 8:53 am

For people in Europe it is quite difficult to understand the mm / inch problems.
From my experience I can tell that it is a good idea to stick to one system, like the SI units in technical or scientifical calculations.
Or mm in technical drawings.
I think it would be a good idea to work with mm internally and convert them on demand in the GUI.
Or to omit the unit and interprete everything as numbers (a more mathematical approach), so the user himself has to take a decision about the units he wants to use. I'm working with a simulation program for system analysis, and I always tell my students that they must decide for themselves if they use seconds or minutes for example for the time scale. When they do this systematically, they don't have problems.

But I an new here and I don't want to push my opinion foreward. It was only a suggestion.
sliptonic wrote:I have a pull request (376) pending now that made some changes and improvements to how depths are handled. With that, I don't see your 10x problem. (I'm not saying that fixes it since the problem might be elsewhere, but please test with that and let me know)

Does that mean I have it in freecad-daily when I update? (I'm not used to git things, still have to learn a lot ;) )
chrisb
Posts: 1668
Joined: Tue Mar 17, 2015 9:14 am

Re: Getting started with Path in v0.17

Postby chrisb » Tue Dec 13, 2016 10:25 am

jcf wrote:For people in Europe it is quite difficult to understand the mm / inch problems.
From my experience I can tell that it is a good idea to stick to one system, like the SI units in technical or scientifical calculations.
Or mm in technical drawings.
I think it would be a good idea to work with mm internally and convert them on demand in the GUI.
Or to omit the unit and interprete everything as numbers (a more mathematical approach), so the user himself has to take a decision about the units he wants to use. I'm working with a simulation program for system analysis, and I always tell my students that they must decide for themselves if they use seconds or minutes for example for the time scale. When they do this systematically, they don't have problems.


The problem might arise when exchanging models with third parties like 3D-Printers, lasercutters, etc. So getting back to your original question viewtopic.php?f=15&t=18628&start=10#p148689 I think you definitely should omit the units there, because it would be wrong for "imperialists".
sliptonic wrote:I have a pull request (376) pending now that made some changes and improvements to how depths are handled. With that, I don't see your 10x problem. (I'm not saying that fixes it since the problem might be elsewhere, but please test with that and let me know)

Does that mean I have it in freecad-daily when I update? (I'm not used to git things, still have to learn a lot ;) )

I will test and report here.
chrisb
Posts: 1668
Joined: Tue Mar 17, 2015 9:14 am

Re: Getting started with Path in v0.17

Postby chrisb » Tue Dec 13, 2016 10:53 am

The error as described here: viewtopic.php?f=15&t=17768&start=30#p142250 still exists.
If someone can help me getting started with the GUI I will look at it. I have never used the GUI, only the python console and macros. So be patient with me. I will do my best but the first steps are always the hardest.
So the first steps for me are
1. finding the appropriate GUI.
2. Learning how values are transferred from and to the GUI.
GeneFC
Posts: 67
Joined: Sat Mar 19, 2016 3:36 pm
Location: Punta Gorda, FL

Re: Getting started with Path in v0.17

Postby GeneFC » Tue Dec 13, 2016 2:30 pm

jcf wrote:For people in Europe it is quite difficult to understand the mm / inch problems.


My comment is not related to the mm / inch problem. As I have said in previous comments I am thoroughly bilingual in measurements.

FreeCAD offers support for several measurement systems. Even in purely metric systems the length can be chosen as mm, cm, or m.

It is simply bad practice to use bare measurement numbers without units attached.

Gene
jcf
Posts: 35
Joined: Tue Nov 15, 2016 10:34 am

Re: Getting started with Path in v0.17

Postby jcf » Wed Dec 14, 2016 2:37 pm

About the post processor:
You only need to put your post processor into your macro directory. As long as the post follows the naming convention <something>_post.py Path will find it there.

Unfortunately this seems not to work for me.

My macro folder is
/home/jcf/Desktop/FreeCAD/Macro/path

And my postprocessor file (modified) is here:
/home/jcf/Desktop/FreeCAD/Macro/path/linuxcnc_post.py

Has anyone an idea what has gone wrong?
sliptonic
Posts: 597
Joined: Tue Oct 25, 2011 10:46 pm

Re: Getting started with Path in v0.17

Postby sliptonic » Wed Dec 14, 2016 3:54 pm

Hmm. I retested with current Master and it is working.

After switching macro directory, I had to save/apply. Exit settings, and re-enter. Then switch to path settings. It was then showing the contents of the Macro directory and the default post processors. If you don't change the name, you'll have two linuxcnc posts in the list. Make sure you're getting your modified one and not the original.
chrisb
Posts: 1668
Joined: Tue Mar 17, 2015 9:14 am

Re: Getting started with Path in v0.17

Postby chrisb » Wed Dec 14, 2016 6:38 pm

It seems that the system directory is always searched first on my system.
  • If I have a post processor with the same name, I see it only once in the selection box and the system file is used for export.
  • If I want to use the local version, I have to move/delete the system's post processor and the corresponding .pyc file.
  • So it's sensible to use a different name for the local version.
BTW is postprocessor or post processor the correct term?

OS: Ubuntu 14.04.5 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.9184 (Git)
Build type: None
Branch: master
Hash: 14e32213747928d3a01ab95cf09f611fa383981e
Python version: 2.7.6
Qt version: 4.8.6
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17
jcf
Posts: 35
Joined: Tue Nov 15, 2016 10:34 am

Re: Getting started with Path in v0.17

Postby jcf » Tue Feb 07, 2017 12:16 pm

Sorry to say that, but I am somewhat in despair:
I thought I had understood mostly how I should do to get my gcode, as I summarized here:
http://staff.ltam.lu/feljc/software/fre ... t_to_g.pdf

But now I run into new difficulties, as I get errors when using the workflow described in the document.

To me it seems as if it had to do with something deep inside FreeCAD that has changed, as the error statements include mentions of edges, lines, curves ...
Even if I try to get a contour path for a simple box, it doesn't work.

I don't blame anyone for this, as I am using the unstable version 0.17

But I am wondering how to get on...

Is there any prevision when the 0.17 version will be stable?
chrisb
Posts: 1668
Joined: Tue Mar 17, 2015 9:14 am

Re: Getting started with Path in v0.17

Postby chrisb » Tue Feb 07, 2017 11:20 pm

jcf wrote:But now I run into new difficulties, as I get errors when using the workflow described in the document.

To me it seems as if it had to do with something deep inside FreeCAD that has changed, as the error statements include mentions of edges, lines, curves ...
Even if I try to get a contour path for a simple box, it doesn't work.
Did you try to create all path related stuff from scratch? That is sometimes necessary when internal structures have changed.
Is there any prevision when the 0.17 version will be stable?
No, but it is probably still far from now.