topic Re: Units change when I export to .stl file in Inventor Forum

Units change when I export to .stl file

bd567771 — Tue, 23 May 2023 23:31:24 GMT

Whenever I design anything in Autodesk inventor 2022, I change the units in document settings to mm and change the unit to mm when I export as a .stl file, but the file keeps saving as cm.

Whenever I export the file in mm (as in, change units to mm under options and in document settings), it exports as cm. When I export as cm, it exports as inches. What do I do to fix this?

Re: Units change when I export to .stl file

johnsonshiue — Tue, 23 May 2023 23:38:59 GMT

Hi! The export unit and the actual document unit should be in sync. For example, if you are in mm, select "mm" in STL Export Options. It should work. Please share the file if it does not work as described.

Many thanks!

Re: Units change when I export to .stl file

bd567771 — Tue, 23 May 2023 23:42:50 GMT

Hello! It's not working like that though, I am not sure why.

Re: Units change when I export to .stl file

johnsonshiue — Tue, 23 May 2023 23:51:29 GMT

Hi! Let me walk through the steps to see what I missed. Open the file. Go to File -> Export to CAD format -> STL -> Options -> select "mm" or Document unit. The STL file should be mm based.

I guess you are using English part template and you import the STL file back to Inventor and it becomes inch sizing. You need to either start a metric template -> Import or reset your template to mm (Tools -> App Options -> File -> Configure Default Templates).

Please try it out and see if it works better.

Many thanks!

Re: Units change when I export to .stl file

JDMather — Tue, 23 May 2023 23:54:48 GMT

@bd567771

Also Attach your resulting *.stl file here.

Re: Units change when I export to .stl file

bd567771 — Tue, 23 May 2023 23:57:19 GMT

I followed those steps and it still converted to inches both in the 3d printing preview window and when I import back to inventor. This is the stl file I get when exporting as mm and converting document units to mm.

Re: Units change when I export to .stl file

JDMather — Wed, 24 May 2023 00:06:07 GMT

I get exactly the same size (although you didn't set to high resolution as I showed in my previous post).

Are you dong File>Open

are you first starting a new mm part file and doing Manage>Import?

Can you show how you are coming to the determination of wrong size?

Can you show image of your Application Options as above?

Re: Units change when I export to .stl file

bd567771 — Wed, 24 May 2023 00:08:28 GMT

It opens in cm in 3D printer viewer (first image) and inches in inventor (second/third image). I did file>open

Re: Units change when I export to .stl file

JDMather — Wed, 24 May 2023 00:11:59 GMT

Tools>Application Options>Files tab

your Default template is set to Inches...

Re: Units change when I export to .stl file

bd567771 — Wed, 24 May 2023 00:17:08 GMT

I keep changing that setting to millimeters but it has inches selected whenever I open that tab. I don't know how to make it stay as millimeters. I am new to using this software.

Re: Units change when I export to .stl file

JDMather — Wed, 24 May 2023 00:20:13 GMT

@bd567771 wrote:

I keep changing that setting to millimeters but it has inches selected whenever I open that tab.

@bd567771

You haven't shown an image of this screen. Tools>Application Options.

The only image you have shown is of Tools>Document Settings.

Once you have made the change to your Default Templates - you will have to reopen the stl for the change to take effect.

Re: Units change when I export to .stl file

bd567771 — Wed, 24 May 2023 00:25:53 GMT

This page keeps reverting to inches. I've already selected millimeters and "ok" numerous times and the file still exports with the wrong units

Re: Units change when I export to .stl file

JDMather — Wed, 24 May 2023 00:40:52 GMT

@bd567771 wrote:

This page keeps reverting to inches. I've already selected millimeters and "ok" numerous times and the file still exports with the wrong units

I have never seen that happen before.

Are you getting this warning?

Do you click Overwrite?

iProperties would seem to indicate that you have not installed all Updates for your version of Inventor.

Install Update 2 and 3 for 2022.

http://manage.autodesk.com

Re: Units change when I export to .stl file

bd567771 — Wed, 24 May 2023 10:36:44 GMT

I have installed all the updates for 2022 now

Re: Units change when I export to .stl file

bd567771 — Wed, 24 May 2023 10:36:26 GMT

I always click overwrite. Do I need to re cad the parts that I'm trying to export?

Re: Units change when I export to .stl file

johnsonshiue — Wed, 24 May 2023 22:34:14 GMT

Hi! When you start a new part (Standard.ipt), what is the default length unit (Tools -> Doc Settings -> Units)?

Many thanks!

Re: Units change when I export to .stl file

ampster40 — Thu, 25 May 2023 14:47:34 GMT

Sounds as if this is still being worked thru but I have to mention this to the OP in that this is a very common problem when dealing with Inventor part files, stl's and 3d printing, unit mismatches happen alot. Some slicer programs have an option built in to automatically resize parts. Some slicers it isn't automatic but does usually provide a way to convert or scale as needed.

Once you have the process figured out, write it down or practice it a few times till you get it right.

Re: Units change when I export to .stl file

kacper.suchomski — Thu, 25 May 2023 21:38:48 GMT

Try to prepare the mesh and export the file through the 3D printing environment.