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Comment by _whiteCaps_ | Hacker News Reader

I post this in every FreeCAD thread: If you're going to start designing something with it, use the spreadsheet tool to make everything parametric. You'll save yourself a ton of time as your designs get more complicated.

Maybe this isn't anything new to experience CAD users. I don't know if other CAD tools do this as I started using FreeCAD after playing with 3D printing.

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You can also use VarSet[0], which I think is easier than spreadsheet since you don't have to switch the workbench.

[0]: https://wiki.freecad.org/Std_VarSet

Did not know about this. How do you see all the properties?

Just click the varset in the tree view and it lists them in the properties pane

The downside of spreadsheets is they can really slow your model down. Every cell change triggers a full recompute of the 3D model. VarSets offer much faster performance while sacrificing a couple spreadsheet features. So always choose VarSets over spreadsheets if you can.

On the one hand it's clearly suboptimal for any change, even ones that nothing depends on, to trigger a recompute. But also it feels like there's something a bit broken with spreadsheet dependency resolution in the first place. I've never been able to nail down a test case, but models seem to go over a performance cliff at a certain point. Ordinarily I'd put it down to something being unavoidably quadratic, but I've had cases where I'm certain that the same model is radically slower after being reloaded off disk.

This is an outdated advice. Spreadsheet is hard to use in comparison to VarSets [0]. Recent changes in 1.1 make them even easier and more intuitive to use.

[0] https://wiki.freecad.org/Std_VarSet

It's very common (Fusion calls it User Parameters, etc.) and indeed nice practice. FreeCAD has a few ways to do it, Spreadsheets but also free-form properties on objects. It's very flexible in this regard.

The Fusion implementation sucks. A spreadsheet is a far more natural way to do this, Im surprised FreeCad is doing it better than the paid variant.

The Fusion implementation is awful - you can adjust one variable, one time, then you have to reopen the dialog to do another. At least for me it's always become non-responsive after a single edit, for years now. I've always assumed I'm just holding it wrong, but I don't know. I've moved on.

The only issue I have with the Spreadsheet is that I need to add an alias for every value I want to use in the Sketch or Part Design workbench. In practice, this usually looks like

    A       B
    width   2mm
    length  3mm

and for every cell in B I add an alias with the same value as in column A. Is there a way around that?

https://wiki.freecad.org/Macro_EasyAlias

EasyAlias macro maybe?

Oh. I didn't even know there were macros. But that looks very useful!

not "maybe" this is an absolute must if using parameters in a spreadsheet :)

Its existence has been used by the devs as a reason not to prioritise fixing user-facing bugs. It really should be in core at this point.

Hmmm - I seem to recall there was at least 1-2 scripts or macros available to help with aliasing.

VarSets[0] introduced recently in 1.0 and mentioned in a grand-aunt comment are a good alternative to spreadsheets used this way.

[0]: https://wiki.freecad.org/Std_VarSet

The worst part about fusions implementation is that you CANNOT edit the User Parameters while you are viewing the part easily. I like to edit the params and drag it around, but it SUCKS in fusion

Super flexible. I love being able to use Python to manipulate spreadsheet data.

Some CAD systems, i think NX for example, let you give it a reference to an actual Excel (or csv?) file, that you edit in Excel.

This seems like good advice. To this day I haven't explored spreadsheets or variable sets, which makes resizing stuff a giant pain in the ass.

This is an area where FreeCAD really needs work: scaling stuff.

I'm not experienced with other CAD programs, but I think scaling stuff works fine.

If you want to scale your entire object, there's a scale part operation in the part toolbench.

But in general you wouldn't want to do this. For most real world part, the dimensions you set are based on real world requirements. E.g. These holes need to be M3 and spaced 30mm apart because that's what the part we are connecting to has, but the space to the next set of holes should scale linearly with the length growing, etc.

If you have requirements like that, you should build them into your constraints. If you do this from the start, it's usually pretty easy to make size adjustments to your model.

Or don't and adjust it in the sketcher? If you name your constrains you can just reference them directly elsewhere.

I think that's much easier as you don't have to go back and forth with a spreadsheet.

Tracking down individual values in the sketcher can get annoying too. Just depends on the complexity of your part

You can name them if you want, and the names will show up in the properties of the operation, and you can reuse the values in formulas.

There's a lot of options, and I think a lot of it is a matter of taste/experience what to use

Other cad tools do support this but in my experience it's always pretty awkward to use. I haven't tried the FreeCAD implementation.

Spreadsheets are better in theory but varsets work so much better in practice.

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