Getting from Inventor to copper is maddening

[paulvdh]

FreeCAD has quite a steep and long learning curve.
The KiCad Step Up workbench is quite good though.

If the methods shown to do it directly in KiCad are adequate for your purposes, you make it easier for yourself to stick with that.

If you need the extra flexibility of FreeCAD, then use that of course. If you’re curious towards FreeCAD as a replacement for that other mechanical CAD program, then go ahead of course. I still do feel that FreeCAD is not mature enough to be used for paid jobs where time equals money. The first “ready for production” version of a program is usually V1.0 and FreeCAD is currently at V0.20.

Instead of experimentation, you can make some calculations of the line width you want in KiCad (which determines some of the rounding in the corners), and then calculate backwards how big you have to make the graphics in your CAD program, to get the end result in KiCad that you want.

“Stuff” can be copied from one footprint to another in KiCad.
In the screenshot below, I first selected some random electrolytic capacitor in the footprint editor, dragged a box around it and copied it to the clipboard.

Then I selected some other footprint (a switch) and pasted the contents there.

In KiCad, the PCB outline is traditionally not a part of the footprint, but of the PCB project itself. You can also import graphics in Pcbnew and use it as the PCB outline. Just put it on the Edge.Cuts layer.

[straubm]

@Velvetgeorge

Finally, my pcb requires an 8mm hole. I added a NPTH pad

Check with your board house if 8mm drill ist ok. Most cheap manufacturers have limits like 6.3mm or so.
No problem, you can always draw a circle r=4 on Edge.Cuts so a hole will be routed out.

[BlackCoffee]

@paulvdh

FreeCAD has quite a steep and long learning curve.

That depends on User’s knowledge of other CAD programs. I came to FreeCAD after 20yrs of using and teaching Pro-E, SolidWorks, Cadam, Cadkey and Inventor (and others). I’ve been using FreeCAD for 10yrs, now…

The real Mystery of FreeCad lies in knowing where the tools are located and how to make the GUI usable. Unlike the other CAD programs, tools are spread out into different Workbenches. But, you can create your own GUI or Move Toolbars and Tool-Icons as desired. Thus, given that PartDesign workbench provides the best similarity to the big Cad programs, it’s simple to place the Tools/Icons into PartDesign Workbench…

For an experienced CAD user, Thirty minutes of exploring is Payday! All the extrusion, cutting, datums…etc are there and are used in the same way as done in the other CAD programs. Often the tools are called something different, e.g., “Extrude” in SolidWorks is called "Pading: in FreeCAD. But, doesn’t Kicad also have it’s unique Syntax for things…

Thus, if user has Inventor experience then, learning FreeCAD is quick and not painful, just a bit of Head-Scratching as user wonders why this or, that is called one-thing or another and where to find it…

Here’s examples of my Tweaked FreeCAD GUI…

[Velvetgeorge]

Thanks for the insight. I learned in Inventor and and am really fast with it. I understand all the 3D CAD conventions. It’s just a matter of applying them in FreeCAD i.e. finding what things are called and applying parameters.

I’ll make time to get my head around FreeCAD. I really want to use it to place my STP files into footprints. And also to export boards to STP with traces and screen printing. If I’ve read correctly StepUP does this.
Do date I have had to export a STP from KiCAD, export a PDF or SVG of the F.screen and do my best to align. The screen file exports huge and is miserable to work with. Not to mention, placing it as a decal in Fusion 360 has never scaled and placed correctly.

Text on the board is crucial for creating wiring diagrams.

[paulvdh]

I don’t want to say (too much) bad things about FreeCAD.
I have managed to conquer some of the workbenches, and I can do a lot with it, but it simply has too many loose ends at the moment to be called “mature”.

The biggest pain is that you can slap a sketch to a face, but if you change the underlying object, then the face gets renamed and the connection is broken. My current workaround is to make the origin of a body visible, then add a datum plane, and attach it to some coordinate and put a sketch on a dataplane. And there are far to many of such things you have to jump through exactly the right hoops to make something that works reliably.

Sketches made in old FreeCAD versions break regularly when opened in newer version. This is a logical result of improvements in the solvers and the way constraints are handled, but it’s a pain to use if you have to keep repairing your scetches all the time.

The FreeCAD people are now working on the 4th implementation of the assembly workbench.
There have also been several paper workbenches for preparing stuff to be printed, and I don’t know if they’ll stick with the current implementation.

Yet another thing I still can’t completely wrap my head around is the difference between a “Part” and a “Body”. Why is there even any distinction between those two?

Another problem that that FreeCAD is quite slow. My new 5600G is not a slouch and it is sufficient to do most things in FreeCAD, but it’s a 6 core 12 thread processor, and I suspect that FreeCAD only uses some 8% of those horse powers.

I also find the way objects are nested quite confusing. FreeCAD remembers the whole editing history in a tree, For example, create a sketch, make a pad from it (extrude), Apply chamfers, add holes, and you can view the intermediate steps. During some editing operation (or making (in)visible) I regularly have the wrong object in the tree because I find them hard to keep apart.

And there are a lot more gotchas in FreeCAD that prevent you from “learning it in half an hour”.
FreeCAD is the only real 3D drawing program I’ve ever used. I was quite fluently in Autocad versions 10 through 12 (back in the DOS days) and even did a bit of 3D stuff in it.

On the plus side:
FreeCAD is a quite powerful program and you can already use it for lots of stuff. If the problems menioned above are solved then FreeCAD is surely ready for V1.0

[BlackCoffee]

@Velvetgeorge Take a look at some of my Tut’s (link to them). You’ll notice the similarity of doing things you currently do in Inventor.

Some of the tuts start out without a Part>Body (but, often they get moved into a Part - did this way only to show users that can be done as an After-thought.

If you watch some, your Inventor hat will stay on your head… so to speak…

The tuts show how to do Text (that’s perhaps the PITA part of it (it’s done in the Draft Workbench)

[BlackCoffee]

@paulvdh , I don’t mean any criticism… But, it seems to me you’re missing some basic understanding of FreeCAD - the stuff that leaves you with shortcomings you mention.

You wouldn’t have ‘Breaks’ if you know how to correctly do the work. Do you know how to fix them? How to Re-Map them? How to use the Validation tools…

[paulvdh]

@BlackCoffee

But, it seems to me you’re missing some basic understanding of FreeCAD - the stuff that leaves you with shortcomings you mention.

You are completely right here.
I know that I’m missing some parts and that I just can’t wrap my head around doing certain things.

Here an example of one of my own drawings.
It’s for a CNC router which would weigh approx 350kg if made in steel.
I used dual rails for the Z-axis to get both stiffnes when working close to the table and have a high reach, for example for drilling holes with a long drill.
Later I designed a simpler version. I’m not sure If I’m ever going to build one of those machines.

@BlackCoffee

You wouldn’t have ‘Breaks’ if you know how to correctly do the work. Do you know how to fix them? How to Re-Map them? How to use the Validation tools…

I’m having the greatest trouble with repairing simple mistakes. If a sketch gets oriented in the wrong coordinate system, then repairing it is a nightmare for me.

I just recently learned the workaround for the face renaming bug. I read it on the FreeCAD Wiki, and that made me realize I have to use a more structured approach to learning FreeCAD.

I hope I’m not hijacking this thread too much…

[Velvetgeorge]

I’ll make time to when I can, thanks!

This project has become an albatross at this point. I’ve spent endless hours attempting to export specifically designed elements from Inventor as something I can utilize in Kicad. I’ve come to export DXF files as AUTOCAD 2000 compatible, it’s surest way I’ve found to maintain scale when importing into Inkscape or Corel.
Once imported, the files have to converted to vector and cleaned up of segments that appear from thin air. OK, done. I know when an object is a closed path as it can be filled.

Today, I have imported all of the elements of this design (which were exported from Inventor as DXF) into Inkscape. Verified the scale. Aligned each object. Assigned to correct footprint layer using SVG2Shengzhen. Export to Kicad…

Only the edgecuts geometry appears. I tried with Kicad 5 and 6. This is nonsense. EVERYTHING almost works. I’ve reached 90% complete on this project a dozen times so far. Only to hit some ridiculous brick wall.

I’ve abandoned my usual habit of taking notes so I can repeat a workable process. There’s no point.

Sorry to rant. I’ve come full circle. As the post title states: the incompatibility between CAD and anything vector-based (in this case Kicad) is maddening.

[Velvetgeorge]

I understand the frustration. Inventor does seem to default to maintaining any associations if possible. Sometimes you are forced to break them.
When you create any entity in relation to another, the reference is implied. If not, things fall apart quickly.

When I assemble multi-part objects in 3D I take care to ground the primary part and constrain/lock other parts as placed.

[paulvdh]

Back to your KiCad rotary switch project:

You’re trying to everything together in one go and that makes it very time consuming and frustrating.

• Getting the coordinates perfect
• Importing 30 pads.
• Sorting out the workflow
• Making notes.

In my experience you have to drop a few things.
Stop with (most of) the notes, and getting coordinates of all 30 objects right.

The first thing you have to get right is your workflow.
For that goofing around with a few quickly clicked together coordinates is sufficient.
And because it is a lot quicker, you can do more experiments.
It’s also easier to share screenshots or design files because there is no important stuf in it.

Then, once you’ve (almost) got your workflow right, it becomes time to take your efforts to a more serious level and use the real drawings. All your experiments are still fresh, so that is the time to make some more detailed notes.

[BlackCoffee]

@paulvdh

I hope I’m not hijacking this thread too much…

Doesn’t bother me…

Your CNC modeling contains a good bit of work - good job. But, it could be better, especially with respect to Up-Front planning and how you do things.

Short of commenting on many aspects, let me just say that next time, Consider using Datum’s (thus, reducing the ‘Break’ problems. And, learning about Mapping and Validation.
That will be big step in a good direction.

The only project I have that’s similar to your CNC is a 3D-Printer - I did only what I needed, not the full machine. Take a look at the Tree (partial view) and how many Datum’s I used. Thus, everything is portable and where needed (for a broken link) I need only make One-Click to reMap… Simple.

EDIT Notice the PCB with Red LED’s (done in Kicad)

[Velvetgeorge]

Very cool. I’ve never used a datum in Inventor. But often use work planes. I assume they are the same, or similar.

[BlackCoffee]

It’s been too long since I used Inventor (these day’s I stick with FreeCAD and SolidWorks(to a much lesser need).

So, I don’t remember Inventor’s exact Syntax. But, Datums (of any ‘Datum’ type including ‘Planes’ should do the job…)

[Velvetgeorge]

Can anyone confirm or deny that the Inkscape export to footprint workflow should work?

I am daft at times, but not completely inept. I’m well versed in computer design and can follow steps in a tutorial.

[Velvetgeorge]

Yep, they do. When you create a new part/body/mesh in reference to an existing object or work plane, the origin is indelibly associated with the new object. It shows up in the project tree like your datums in FC.

[BlackCoffee]

Consider using the Coordinate Origin’s as the Reference instead of other Part/Bodies/Surfaces…etc. This produces same output but provides portability with fewer Breaks (sure, depending on the projects involved, you may need to Re-Map to new Coord system/planes. But, it’s quick to do… And, the attached planes are movable!

[Velvetgeorge]

Interesting. I’ve become spoiled by what Inventor calls "project geometry’. You start a sketch and select existing geometry, project it and can create new geometry from that reference.

[BlackCoffee]

FreeCAD does the exact same thing. In fact, you can select the Face of a Body and Pad(Extrude) or Cut withOUT even making a sketch! Of course, it’s thus linked to the Face. But, that can be reMapped with one click.

[paulvdh]

I started on that CNC machine drawing 4 to 6 years ago. I’m not even sure datums were implemented in FreeCAD back then. And although there are a lot of individual “Bodies” in that drawing, almost all of them are very simple padded sketches, and objects like that do not need a datum plane.

@BlackCoffee Can you share that drawing (or a similar one)
I don’t care about it’s contents, but I want to examine the underlying structure as a reference to improve my own FreeCAD skills.