Unitless ojects importing to inch instead of mm

[mrCharles1]

So, I have an STL file for which I'm trying to import, convert to solid using mesh enabler to edit. The problem is that inventor defines the unitless units as inches instead of mm. As an example, this part should be 25mm tall but is instead imported as 25 inches tall, and changing document settings only changes the units, not the scale of the object. This causes problems when 3d printing.

How would I go about choosing what unit Inventor chooses for my file?

Using Inventor 2021 Professional 

[JDMather · Accepted solution]

Do not open the stl file directly.

Start a new file of correct units.

Import the stl. 
Attach your stl here if you can’t figure it out.

[mrCharles1]

I'm dumb.. Thanks!

[Hikakiller]

Unfortunately when importing it inside inventor, Mesh Enabler doesn't work - but when opening it seperately it does.

[JDMather]

No difference.

Right click on the mesh node in the browser.

If the option isn’t there then it isn’t loaded.  Go to Tools>Addins to load.

Still can’t figure it out?  Then Attach your *.ipt (and/or *.stl) file here.

[Hikakiller]

Sorry, it does work, but in MM it has so many errors it cannot be converted to a body. In inches it works fine.

[johnsonshiue]

Hi! This usually means the original body was modeled in inch. When the body was exported to mesh, the literal dimension in inch was taken. For example, 1 inch was exported as 1 unit. Then on importing to a mm template, it becomes 1 mm, which is 1/25.4 of the actual size.

Many thanks!

[Hikakiller]

Unfortunately that doesn't sound right either. It's this main body ipt on
the below website. If this were modeled in inches, it would be 12 feet wide
or something, which Is obviously oversized for a mousetrap.

https://www.thingiverse.com/thing:2815083

[johnsonshiue]

Hi! I took a quick look at the stl files. I think they were modeled in mm, not inch. But, when you import them to Inventor, you need to click on Options button in Import dialog -> select mm as the unit.

You probably had an English template. As a result, it imports based on the document unit, which is inch. Then it leads to a huge model.

Many thanks!

[Hikakiller]

Welcome to the end of my thought process.

You said to import the file im MM. I said that when I do that, it causes errors, but I know MM is the right scale. You said I need to import it as inches, but that makes it 12 feet wide. You said it really DOES need to be in MM, which I said from the beginning. But that causes errors.