Export to STEP file

I need to export a 3d file in STEP file format. Can anyone help?

You might find this old thread helpful.

AFAIK there isn’t a way of doing it directly from SU in one process.

Thank you John for the help.

Hi John,

After searching thru the results of the thread you sent, it seems I would need to buy new software to create a step file. I would rather not spend the money and I am not confident I would be successful. So, if I may ask another question. Is there any way to find a solution using SU? I may be able to send a copy of the file if you want to see it. But first let me give you a brief description of my issue.

I have designed and had fabricated a fuel tank system for a boat. It consists of a port, a starboard, and a day tank. The issue is, the port and starboard tanks are non-symmetrical shapes, in which I am installing sending units to read fuel levels at 4 given points, empty, 25%,50%,75% and full. This is what the supplier needs a step file for to make the calculations. Can SU show these 4 equal volumes in such a shape?

From what I can deduct, step files are used for cnc or 3d printing, which is not what I am doing in this case.

It all depends on the shape of the tank, if it’s all straight edges, you might get the total volume, and then use a trial and error method to get the quarters.
As soon as there are circles or curved surfaces involved, inaccuracy rolls in due to the segmented nature of the meshes SketchUp creates.
There is software that can turn meshes into calculated solids, but why not create true solids in the first place?

Can you share the model(s) of the tanks? As @MikeWayzovski suggests, it should be possible (if the tanks are drawn as solids) to use trial and error to locate the quarter and half positions, by placing horizontal faces to intersect the tank, then seeing what the volume is in that position, and adjusting up or down to get a close approximation.

STEP is actually a CAD interchange format, you are probably thinking of STL for 3D printing. They probably want STEP as they can very accurately take the measurements needed for that type of file, its also quite Universal so almost all CAD software can read it, its the CAD equivalent of FBX…

If you don’t manage to find a solution in SketchUp you can use a 30 day free trial of Fusion 360 to make the new export the file pretty quick: Download Fusion 360 for Free | Free Trial | Autodesk

I use Freecad to export to .STEP. Its free and relatively simple to use. You need to export the sketchup file as a STl, then import and convert the mesh to a shape with freecad. Once complete, you can export the shape as a .STEP file.


I took your advice, first I tried Autodesk and as feared my work is not up to it. When I uploaded my tank file it showed major problems that did not show in SU. I think I am finally getting the reason for grouping. Anyway, when I tried converting into a STEP file it failed.

So, I moved on to the more sensible suggestion, for me anyway, I manually divided the tank into four sections and that worked. In the process discovering solid inspector, what a great tool that is.

Here is my work, the volumes are not all equal, but I have is good reason for that.

Thank you all for the assistance, please feel free to critique my work.

Fuel Tanks Master.skp (1.2 MB)
Fuel Tanks Solid Volume.skp (842.8 KB)

tl;dr: imagine facetted meshes (SU) like pixels vs. curve-based surfcaces/solids (CAD) as vectors.

Simply saving pixels to a vector file format wouldn’t convert them to vectors… if possible anyhow… converting e.g. tesselated SubDs to NURBS would be required before.