Folding sheet metal


I’m using Sketchup Make for a few years and considering to switch to Sketchup Pro. However, I noticed it’s not easy to find a way to (un)fold/ bend sheet metal, in order to create 2D drawings.

Am I missing anything? Can anyone advise how this can be done with the Make or Pro version?


Can you show an example model that you want to unfold? There are a few different extensions out there that would probably work for you.

There are several tools available - most should work in all current versions…
e.g. look for ‘Flattery’ at the’s PluginStore…

Hi Dave,

Please find file attached. DS_01_01_010.skp (228.4 KB)

The one TIG mentioned would work or you could use Unwrap and Flatten from the Extension Warehouse. Here I copied the outside faces from your part and flattened them.

What will you do after you have it flattened? What’s the application?

FWIW, if you want to show the flattened piece with thickness, your could run CleanUp3 to delete coplanar faces and then Push/Pull to create the thickness.

I’ve successfully used Flattery before, but you unfold stuff manually one joint at a time. Dave’s suggestion looks easier and quicker for the example shown with radius curves.

In some cases this supposed method is not accurate enough.
Nor the outside or the inside face have the real length of the metal piece.
The real length is somewhere inbetween.
Read up on metal bending here:

That’s true. It depends on what is needed from the model which we have yet to be told.

Working out the centerline through the part could be done and that could then be unfolded.

I’m used to Solid Works and Catia and there you just design a 3D model (sheet metal) and after adding the type of material, you can unfold it to create a 2D drawing for bending and laser cutting.

With this model I would like to do the same. Unfold, create a 2D .dxf to send to the laser cutting machine. Therefore once unfolded, it should be accurate.

After bending it should have the same dimensions as the 3D model.

I will try your suggestion later today and share the outcome.

In order to get the .dxf export you will need to be using SketchUp Pro. Sounds like this might be a thing for your work so you’ll need pro anyway.

Hi Bep,

I also noticed that. As an engineer I always check the drawing by calculating the (flat) dimensions myself. Catia and Solid Works are very accurate, once you added the type of material. I have my doubts with Sketchup.

Hi Dave,

Please find my creation attached… This was done with Pro that I’m trying for a month.

I have notice that every time I execute the flatten tool, the outcome is different :slight_smile: Any suggestions?

You’re trying to unfold the entire volume. Go back and look at my GIF and screen shots. You only need to unfold the large surface with no thickness. That’s why

And, following BEP’s description in my third post, show just a surface cutting through the center of the sheet.

@gersonpape, folding the center face should be very accurate, depending on the radii of the bends (and material).

Hi Dave,

I have followed your instruction and it works fine. Thanks! Its not accurate enough yet, but I guess that has to do with the K factor (type of material). I haven’t found where to select that yet, but will get there.

Thanks again.

I think you’ll have to deal with the K-factor manually.

Where do you select the type of material? Dave unflattened the inner part. Why would you do that? I would have chosen the outer circumference.

I initially flattened the outer surface of your part. After Bep’s comment I showed flattening a surface created through the center of the material.

There is no way to choose the type of material. You would need to know the K-factor and use that to figure out the radii of your bends manually.

Got it! Thanks again.