Annotations in microns

[Anonymous]

I am setting up a project in microns.  How can I do annotations in microns rather than mm?  This as DXF files are being scaled by 1000 when uploaded in another software such as coventorware.

[-niels-]

You don't specify if you want it for annotations in part sketches or in drawings but you can change the unit settings in both situations.

For parts, go to the document settings:

For drawings, change it in the annotation style:

[johnsonshiue]

Hi Guys,

If you do want to model in such smaller scale, I suggest you stick with mm in parts and assemblies. Then you simply point out that the drawing is in micron. Make sure the view scale factor is shown correctly.

Normally I would not suggest this, because Inventor is a true-scaled CAD system. Every piece of geometry should be exact regardless of units. The reason why I suggest this way is that in such small scale, you may find creating and editing sketch difficult.

Many thanks!

[Anonymous]

Thanks for the reply.  I understand that for parts you can change the units to microns.  However my difficulty is if you can change the annotations to microns?

[johnsonshiue]

Hi! You don't want to change the drawing dimension to micron, because the values will be wrong if the body geometry is based on mm. My proposal is kind of a hack. Basically, you just dimension in mm (without showing the unit). Then in the titleblock, you note unit as Micron.

Many thanks!

[-niels-]

@Anonymous, can you explain the problem a bit more? what exactly do you mean by annotations?

If i change the units to microns, the model is in microns.

Is the problem more related to the dimensions of the .dxf perhaps?

@johnsonshiue, bit surprised by your advice, if Inventor has the option to work in microns then why not use it?

Then again, i've never had a need to do so, so i'm not aware of possible limitations...

I'll direct the last bit of my comment to you, regarding dxf's exported units:

If you export a file from Inventor that was set up in microns as a dxf, then import it in AutoCAD, what units does it have in AutoCAD?

(i think this is where the actual problem is)

[johnsonshiue]

Hi Niels,

1 micronmeter is 0.001mm, while Inventor body geometry is accurate up to 0.00001mm in true scale. So in theory, the intended geometry is 100 times bigger than the tolerance. The geometry compute should be fine for sure.

The issue is more about how to interact with the geometry (selection and viewing behaviors). In such small scale, Zoom In/Out can be difficult. The cursor behavior can be jumpy. It is just not practical to model in such scale efficiently, though the geometry will hold true. It is more about usability concern. I have tried it but I don't think it is a usable modeling environment. The experience is not pleasant. This is why I don't recommend the workflow.

In such small scale, 3D Printing is not an option yet. So true-scaled geometry isn't a requirement. As long as the geometry works proportionally well, the unit will become optional.

Many thanks!

[Anonymous · Accepted solution]

I am designing MEMS devices which are in the micron scale.  I design the masks on inventor and transfer the dxf to coventorware for simulation.  Coventor dimensions the DXF based on the annotations.  Hence if I design a line 1000microns long the annotation is shown as 1 as inventor represents the annotations in mm where 1 (mm)means 1000microns while coventor takes it to mean 1 micron.

Hence why I am asking if there is a way to annotate in microns rather than mm.  Drawing in mm to mean microns seems to give best results at the moment although it is not ideal as such....