Anyone here that has moved from CAM in Fusion 360 to FreeCAD Path Workbench? I want to make that move and would like some information about what to expect.
I have made that move.
It’s a bit like going from Windows/Mac to Commandor 64 in some cases. What I mean FreeCAD is not as polished in graphics but does what you would expect.
Okay, what do you want to know?
Some data of my needs:
- I mill mostly in aluminium on a router so feeds and speeds, multiple passes, depths etc. not to break the bits but be able to use the router to its maximum capacity is important.
- Postprocess to Mach4.
- I use a lot of 2D Adaptive in Fusion 360.
- Rest machining (or workarounds to do get the same result).
- Doing “arrays” or similar (repeat a process step with coordinate offsets).
- Wold be great to insert custom G-code directly in the job without using macros.
- Mill from a stock modelled in FreeCAD or imported from step.
- Do not need 3D operations today.
I could simulate the generated G-code in an external simulator if needed.
The “not so polished graphics” is not a problem.
Have you felt the need to go back to Fusion 360 in come cases?
Just want to make one thing perfectly clear, why I moved.
It has to do with them rewriting the Licence to use F360 freely and the realisation that it would not be the last time the licence would be rewritten.
I am school trained in CNC has as a profession to run CNC machines.
With this background, I think that FreeCAD 0.18 creates enough good NC code for me, the later versions are better, but I can not handle the new GUI that has been introduced in FreeCAD 0.2—> and the lack of texts explaining the function I intend to use.
I have also fixed my own NC code checking programme, so that the NC programme is more easy to work with.
I just use FreeCAD as a driver to get NC code to make fun things on my little table top CNC milling machine.
Sorry, this was long.
I have been a paying Fusion 360 customer for years and Autodesk just increased my monthly subscription fee by 170% without even notifying me so I’m looking for alternatives.
That’s what I suspected would happen, I’m glad I left Fusion 360 Autodesk.
Here’s a video on what looks like a good page to find out RPM and feeds, NOTE haven’t had time to test this myself.
Online Feeds & Speeds Milling Calculator
https://youtu.be/L3t1_4VyLXY
Have run out NC code to Mach3 and it has worked fine.
Do not have Mach4, so I can not answer that.
FreeCAD’s Adaptive Milling is okay.
Rest machining is moving into the newer version of FreeCAD as I understand it.
I have not tried “arrays”, so you will have to hope for someone else’s experience.
You can do this in the simple NC code editor that appears the step before the NC code file is saved.
This is how I prefer to work, I think it works fine.
There is an NC programme simulator in FreeCAD, which is good enough for me and I want more control:
https://nraynaud.github.io/webgcode/
I decided that I would sell my cnc mill for scrap before I gave Autodesk another dollar. It is a clear case of cutting off my nose to spite my face, but I’m old and cranky enough to stand by my principles… plus I do this stuff as a hobby now.
I give money to the Freecad developers instead and don’t have any regrets about it. That’s me though.
Often Path Profile can be used as a workaround
- Doing “arrays” or similar (repeat a process step with coordinate offsets).
PathArray can do linear or two dimensional repititions.
- Wold be great to insert custom G-code directly in the job without using macros.
You can insert arbitrary custom G-Code between other operations.
I still have Fusion installed but don’t find much need for it. It’s good software if you don’t mind the cloud and the company behind it.
FreeCAD’s simulator is frankly not very good. Camotics and NC Viewer fill that gap. It’s not either/or, they do different things.
https://ncviewer.com/
https://camotics.org/
Rest machining is a missing feature at this time but it will happen. As Fusion continues to split features off into various tiers and packages FreeCAD will continue to improve and continue to be open source.
Have tested some more in the Path WB and so far it is looking great.
Have yet to find the work flow that I want going from a model in FreeCAD or step to a CAM program, where I want to keep the model/step file separate from the CAM file. Need to learn some more FreeCAD to find this workflow.
Use Links.
Create your new empty CAM file and save it. Switch to your model document and select the body / part you want to cut. Switch back to your new CAM document (use the document tab at the bottom of the screen to switch so you don’t lose the selection).
Click the link button.
2023-07-07_07-08.png
This places a linked copy of the object in the cam document. Treat the linked object like any other and create your Path job from it. The link is parametric and will update if the source document updates.
Thanks,
Using Link and the SubShapeBinder solved my workflow issues. I needed to make some additions to the model but without affecting the source model to make effective rest operations.
Rest machining seems to be ready to go in the next version. Right now we are in a dead feature period waiting on a release.
I’d still give freecad a good future, even though it has shortcomings in some area.
If your object has lots of round shapes and you are under time pressure — go for Fusion 360
If it’s a rather simple object and you have time to get into it go for FreeCAD.
I designed an SMD Pick and Place machine with an accuracy of around 10-20 micrometer including 8mm SMD Feeders and did all the CAM stuff with FreeCAD (I also wrote the PNP Software and controller firmware for the machine and feeders myself). There were some very challenging parts involved, and some design decisions in FreeCAD I don’t agree with due to poor performance (eg. extensions in the path module). I’m running my own version for a longer time, it took me around 1 month to study and modify FC according to my needs.
Fusion would have been way easier - but my problem was that I was new to machining as well and wanted to keep the cost as low as possible (in case of a failure I wouldn’t have lost too much money, however the project succeeded, the machine is being operated regularly now).
It turned out that the biggest cost was the tooling cost.
Long term I’d definitely advise to learn FreeCAD. Study some Python and C++ code of FreeCAD if possible.
Do you think this hold also for round shapes in XY-direction? The limits there don’t seem to be too serious.
My 8mm aluminum feeders have cutouts and top / bottom pockets. FreeCAD/opencascade is building up complex situations over time within a single BREP structure itself.
To resolve those situations someone can explode and sew the faces together again in the Draft workbench, that’s how I got the loading time down from 30 minutes to a few seconds again.
It would be better to have an option to rebuild an object; however I think this might add another issue with tolerances from time to time.
The other time consuming killer was the path extensions, I completely rewrote that for my purpose – no auto detection anymore which performed the cpu intensive isInside check (on a complex model it’s painful).
No progress so far. There was no chance to get anything usable out of Freecad path workbench so far. 
This isn’t helpful or accurate. People are using Path successfully every day. Do you want to talk about something specific and actionable?