Confused about using dimensions for furniture modeling

Hello there,

A little Intro:
I am a furniture maker and have long been using SketchUp for drawing my work, but would love to finally switch to an open-source solution ('have been a Linux user since 12 years…).

I tried FreeCAD, and although it may be the recommended software for this, I don’t find it intuitive, I don’t like creating parts and then assembling them…

Blender seems to suit my needs better (also works in many regards similar to SketchUp).
But my problem here is, that I cannot figure out how to create even the simplest shape and give it exact dimensions. I activated the MeasureIt addon, and in Object view I can see the Dimensions of an object… but they don’t correspond to the measurements?

Please don’t just respond “Blender is not a CAD program”… I know it’s not supposed to be, but there are people out there using it as such… and I’d like to try that too :slight_smile:

The one thing that comes to mind is object scaling. Always make sure to apply the scale of your objects (ctrl-a in object mode), as un-applied scalings lead to all sorts of problems.

Thanks. I am not exactly sure what the apply functions are for… but it did seem to solve this issue.
Still lots to learn!

Glad it helped!

If you scale an object in object mode these values here change:

If you scale the cube in edit mode, however, those numbers will not change, instead, the geometry of the mesh itself is modified. While the object, after both scaling methods, may look the same in object mode, there are instances where the methods lead to differences (one is your example). In other words, the Transform settings of an object are operations that are applied in a global fashion to the whole underlying geometry.

When you apply the scale, the scaling in object mode (the numbers in the screenshot) are applied to the geometry and the numbers reset to 1.000, while the apparent dimensions in object mode do not change. (resetting the scale (alt-s in object mode) just sets the numbers back to zero without changing the mesh, meaning you will see changes in object mode).

Again: make sure to always apply your scale, there are very many instances where non-applied scale (especially if the scale for x,y, and z are not all the same, i.e. “non-uniform”) leads to issues.

Great, now I understand what is going on. Thank you :slight_smile:

I see there is a really helpful community out here answering newbie questions like mine, makes me more confident about digging deeper into Blender.

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Some resources that may help, the manual, apply and a website about precision modeling.

Thanks for those links. The “Different Angle 3D” videos seem to be just perfect for me.

I also briefly played around with the Python API. I have a bit of experience with Python, so this may be a great way to automate some things in my designs.

Yeah, good luck, I tried some bash scripting once and that’s about as far as I got… Not too good at it.