Questions about Path WB

[cnc_learner]

I am reading the tutorial example for Path WBhttps://www.freecadweb.org/wiki/Path_Wa ... patient/de. I have a couple of questions about the Path module. First take an image from the tutorialhttps://www.freecadweb.org/wiki/File:Pa ... Window.gif.

Question 1: Using predefined curves as toolpaths: those green lines are the toolpaths generated by FreeCAD. Can I use predefined curves as toolpaths in FreeCAD? That is, these toolpaths are not generated but defined by some curves?

An associated question with this question is that: if FreeCAD allows predefined curves as toolpaths, is it necessary to do 3D modelling for converting these toolpaths to gcode?

Question 2: Multi-axis machining: say when machining an exterior surface of that cubic, can the part rotate around Y-axis gradually from angle zero to a specific angle?

Questions 3: Customized cutter: can FreeCAD allow user define customized cutter tools? What I am going to machine are plastic, I will use profile cutters for efficiency.

Thanks for help!

[chrisb]

Hi cnc_learner, welcome learning about CNC!

ad 1: You can use e.g. a sketch or draft in a plane and apply a profile from edges operation on that 2D geometry.

ad 2: It is not integrated in FreeCAD yet, but sliptonic has shown a prototype for that, look at his video channel. User apeltauer has posted a video in the video section of the forum, where 5 axis machines are used.

ad 3: Arbitrary shaped cutters are not respected yet.

[RatonLaveur]

to chrisb's answer I would add, tentatively:

ad 1: You can use e.g. a sketch or draft in a plane and apply a profile from edges operation on that 2D geometry.
---- If all you want to work on is wires, you can also use the "Path From Shape" tool, that will output raw G-code based on wires.

ad 2: It is not integrated in FreeCAD yet, but sliptonic has shown a prototype for that, look at his video channel. User apeltauer has posted a video in the video section of the forum, where 5 axis machines are used.
---- Sliptonic's work on 4th axis is demonstrated to work, his video on the topic of PVC machining is a stellar example.
Also, checkout Russ's work in the https://forum.freecadweb.org/viewtopic. ... 2542bf848d
It is very experimental, but will show you the exact status of the most advanced multi-axis FreeCAD can do at the moment.

ad 3: Arbitrary shaped cutters are not respected yet.
----Yup.

[chrisb]

If all you want to work on is wires, you can also use the "Path From Shape" tool, that will output raw G-code based on wires.

Good to hear that it is still working on your side.
Although I did not change it EnableExperimentalFeatures all of a sudden vanished. Even after reenabling PathFromShape did not reappear - I remember it was in the supplemental commands, right?
Is this due to OpenCamLib not being installed, which requires EnableExperimentalFeatures as well?

OS: macOS 10.13
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.16694 (Git)
Build type: Release
Branch: master
Hash: cd74f2e92908e94f9f7bc718e1be52939647b844
Python version: 3.7.3
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: German/Germany (de_DE)

[chrisb]

Can anyone see what I made wrong?

[herbk]

Hi Chris,

Can anyone see what I made wrong?

On my system it's still there.
But i have only the line "EnableExperimentalFeatures" at the Parameter Editor for Path WB since some time.

[sliptonic]

Can anyone see what I made wrong?

Nothing. It looks like a side effect of PR 2157. I think the intent was to attempt the import and write a helpful error to the console if OCL didn't successfully import. Instead, if OCL doesn't import, it returns False for the experimentalfeatures in general.

[chrisb]

Thanks for the info. It's easier to accept an issue , if I know the reason for it.

[cnc_learner]

Thanks everyone for the helpful advice.

@chrisb, I found sliptonic's short video demonstrating 4/5-axis machining, he didn't tell how he did that in that video.

@RatonLaveur, most paths are wires like with one exception: the part to be machined will tilt around Y-axis with either a fixed angle or a changing angle.

Here is an amateur question about generating 4-axis gcode: can I generate 2/3-axis gcode first, then manually add angle A or B to the generated gcode?

Can anyone point me to the right direction in learning how to generate 4-axis gcode programmatically?

Thanks again!

[sliptonic]

@chrisb, I found sliptonic's short video demonstrating 4/5-axis machining, he didn't tell how he did that in that video.

Can anyone point me to the right direction in learning how to generate 4-axis gcode programmatically?

You're right on the bleeding edge of feature development! Information is going to be spotty and subject to change.
I did the video using my own implementation of a 4th axis carve. https://github.com/sliptonic/FreeCAD/tr ... e/4thcarve

At the same time I was working on my implementation, Russ was working on Surface improvments and included 4th rotation as well. These two threads have some information:
https://forum.freecadweb.org/viewtopic.php?f=15&t=36018
https://forum.freecadweb.org/viewtopic.php?f=15&t=26469