Do you always have to use parametric modelling when drawing sketches (Freecad)

[Brandon]

A video I watched said that you should always use parametric modelling when drawing sketches. So do you always have to use it or do you only use it in certain scenarios. Greatly appreciate any answers

[Geit]

Well, sketches are there to create complex surfaces from measurements. Of course you can just add some squares and circles and give them more or less sizes to get a quick result.

But if you want a bigger version later on or a change, then this results in a lot of work as you need to resize, realign and recenter stuff. Just take your dog tag for example. If you want a smaller version you need to change sizes for the text and the hole, too. While a fully parametric model just takes a new outer radius and done. (involving FreeCAD text as an example here is a bad idea, but you get what I mean)

Even for simple things this is a good idea. Better to it right once, than waste time over and over later on.

Since a spreadsheet is a good way to start anyway to get real world measurements into the CAD application, it saves time when drawing them and prevents errors as you cannot make a typo. In the end model sizes react on the spreadsheet as a benefit from that.

Naming sketches and operations will also help to get into old models later on. Basically the same rules apply for software development. No numbers in documents and long labels.

[Ender5r]

It really doesn't take much longer to create a model parametrically. Hardly seems worth not doing it.

[irvshapiro]

The short answer is no. You do not have to replace your dimensions with parameters but it is best practice. Overall for me, if I am doing a throwaway model, that I am only going to use once I just hard code in the values. If I am going to share the model I like to take the extra time to put the parameters in a FreeCAD spreadsheet.

[roon4660]

This discussion led me to look up the difference between Parametric and Direct modelling. You need to know more than I do about 3d modelling to understand the explanation.