FreeCAD WorkBench to import CBfiles

[dave benson]

Hi All
To be clear, I've done all my testing with 0.17 as that's what Carlo's using, but as a "Daily Driver" I use 0.18 as I'm very Interested in the A2plus Workbench and there are
differences between 0.17 and 0.18 (improvements)  not least of which is the QT5 and Python3.

Because I started early with Freecad, a lot of my drawings needed to be migrated to 0.17 and 0.18  from 0.15 and 0.16

One of the biggest pitfalls is to have a "sketch attached to a face" rather than a Datum plane (this is ok for simple geometry that's not going to change later on in the drawing)
But if you modify the face (that your sketch is attached too) later on in the drawing, and there's no longer any solid surface under the sketch your drawing will break.

IF you are going to use Sketches you should start your drawing with a PART and a BODY,  this way you can use the transform tools which don't show up in the
drop down menus  otherwise.

From the Freecad site:

Advice for creating stable models
The idea of parametric modeling implies that you can change the values of certain parameters and subsequent steps are changed according to the new values.
However, when severe changes are made, the model can break due to the topological naming issue that is still unresolved in FreeCAD.
Compared to previous FreeCAD versions, breakage can be minimized when you respect the following design principles:

Avoid as much as possible mapping sketches to faces of the model. Place your sketches on standard planes, or on custom datum planes.
Sketches attached to planes are less at risk of being unexpectedly reattached to a different reference.
When creating datum geometry, do not base it on the part topology, base it on standard planes/axes and/or sketches.
Use a "master sketch". That is a preferably not too complicated sketch which contains basic geometric elements of your model.
These elements can be referenced when modeling subsequent features.
Such a master sketch will often be the first sketch in the Body but it doesn't have to be; in fact you don't even have to use it at all for anything else but being referenced.
If you inevitably have to reference an intermediate feature, e.g. the result of a thickness operation, use the first reference possible in the list of subsequent features
where the referenced geometric element occurs. From FreeCAD 0.17 on you don't have to use the latest feature.
If you take an early feature as reference, all changes to intermediate steps won't break your model.
And again it is better to reference a sketch than edges and vertices of a solid.

Dave

[EddyCurrent]

The only reason I installed FreeCAD was to help Carlo with his project, my CAD software is actually Rhino 3D.
With that in mind, is it better if I install FreeCAD 0.17 or FreeCAD 0.18 ?

[dave benson]

HI Eddy
I just tried 0.18 and compared it with 0.17 and as far as I can tell they perform equally well.
So Perhaps you could continue with 0.18 and I will continue with 0.17, for windows at least, Freecad
behaves pretty well, but there may be more issues across  different OS's rather than between versions.
There are many flavors of Linux and I think this is where the trouble lays.
Dave

[onekk]

HI Eddy
I just tried 0.18 and compared it with 0.17 and as far as I can tell they perform equally well.
So Perhaps you could continue with 0.18 and I will continue with 0.17, for windows at least, Freecad
behaves pretty well, but there may be more issues across  different OS's rather than between versions.
There are many flavors of Linux and I think this is where the trouble lays.
Dave

Hi Dave benson, in Linux, the AppImage is a good way to go, to avoid many problems, only a quite recent libc and X are required and used by FreeCAD, all the remaining libraries are included in the AppImage (as you can see if you decompress it as I've done).

The thing is different if you plan to develop, as version of Qt compatible with those installed is needed to build the Interface builder i.e. to develop a "preferences" Tab under FreeCAD.

And this is a problem because you have to compile FreeCAD from scratch only to use the part used by Qtcreator to build the dialogs that have to be incorporated in some place of the FreeCAD interface.

In my case using Devuan (the packages are the same as Debian Stretch) and not Ubuntu make the thing quite difficult and time consuming (To compile FreeCAD from scratch you have to compile many "base" libraries like OCE and VTK much newer than those shipped with the OS).

This is the little I know about FreeCAD (for now, i hope to know more in the future).

My working is in progress (a little late as I'm developing some little things on CamBam, and I need to "retarget" my brain to C#), and I plan to release the new beta next week. This WE is very busy due to family "work".

TIA for the interest to all and Regards

Carlo D.

 

[pixelmaker]

In the "../Mod/OneCAM-FreeCAD" folder there is a file called "OCB_Gui.py"

Open the file in the text editor change the line with "from PySide import QtCore, QtGui" to
"from PySide2 import QtCore, QtGui", save the file.

In the "../Mod/OneCAM-FreeCAD" folder, Delete all files with *.pyc extension if exists.

                                Run FreeCad.

   Armando

Done, now I get a new error if I choose the OneCAM Workbench: 'module' object has no attribute 'qApp'

ralf

[onekk]

There are some differences between Qt4 and Qt4 despite the fact Qt5 manifest says that the migration from Qt4 to Qt5 is easy.

Many Widgets are migrated from QtGui to Qwidget so the transition is not difficult.

sayd so, I have to use the Qt4 version as my distribution is using it but i plan to see if it feasible to work even with 0.18 in the "near future".

For now it is a heavy experimental "piece of code", mostly an exercise to learn FreeCAD internals to make WorkBenches, but as it is decently usable to make simple works, as the main goals is to import CamBam entities and related them with MOPs to obtain a 3D extrusion of the pieces to work on them with FreeCAD tools.

These pieces are meant to be cut with my hobby router table so are simply 2.5D operation with no exotic things, mostly pocket and profiles.

Plus as FreecAD itself is a WIP code, and many internals are not well documented (slightly better than in CamBam, but not fully diocumented yet and "subject to change") my help on some errors are limited to be able to reproduce on my "working machine"

I'm working on a version that could take account of some differences between Qt4 and Qt5, via some "if then else" in the problematic pieces of code but I need help with OS and version different from those I use, Linux and 0.17 AppImage.

To worse the things, in Linux there are many "distributions" and some of them make the things difficult by packaging they own version of the program patching the code to make it work on the actual combination of libraries "officially supported" by the distribution, so the AppImage is a safe foundation to work on.

So the AppImage is based on a some basic "component" like the glibc and X infrastructure, where the things are more stable and not changing too soon. The relevant libraries such Qt(4 or 5) and OCE and Coin and Python and so on are contained in the AppImage, plus you can decompress it and see the "building tree".

All said is to explain to those don't know how the thing are working under the hood of many actual "pieces of codes" around.

Thanks for your help and interest on this "experiment".

Soon I will publish a copy of OneCAM with the "MOP data extraction" working, I'm developing the "working code" to extract them from the xml file.

Regards

Carlo D.

[onekk]

New beta:

Maybe some chances that it will work on Qt5 (I've put a line that is used to discovery the qt version) and added two check when creating some widget.

Added the first attempt to parse the MOPs, for now it is limited to a simple display of the part an mops (profile and pocket for now) and retirieve and display "name and related primitives"

TIA for the comments and test and my best Regards to all.

Carlo D.

[EddyCurrent]

Works okay on;

Windows 10
FreeCAD 0.18
Qt 4.8.7
Python 2.7.14
Pyside

But it sounds like we need a new cb test file with MOps