conversion to .stl

[kennycoulter]

I seem to be having trouble, but not in converting the format.....

the end result for something circular keeps going out of round afte rthe conversion.     When opening the .stl in inventor, I can't confirm this distortion because I can't seem to find a way to use the inspection tools.  I am trying to print a prototype for work, even though the drawings show correct, my superiors want a working correct prototype.

here is my question from a 3D print forum explaining the same:

I use Inventor to create my objects, and save into the correct format, but when I open these objects in Makerware, I need to scale them.
I have gotten use to this, but I finally noticed the "runout" on round objects wasn't due to the accuracy of the Makerbot 2, but due to scaling issues.

On my current open object, I keep selecting for the X direction to be 59.51mm, and no matter if I select the 'uniform scaling box' or not, it is changing my Y and Z directions. If I hit Enter or click on a new line, the Y direction keeps changing to a new number, in this case, 59.65, and every new change keeps adding .01mm after hitting 'enter' on the keyboard.

No matter what I change, it will not let me make my objects perfectly round.

Has anyone else experienced this or: know why it happens or: what to do?

[MariaManuela · Accepted solution]

Hi Kennycoulter.

Welcome to Autodesk Discussion Group.

Why are you not set the scale in export option? You are exporting in 1:1?

In Inventor - File \ Print \ send to 3D Print Service. 

[kennycoulter]

I want to say that my co-worker recommended it previously, when I first bought my printer, and it either didn't work for me or I misunderstood.   I am currently printing another version, and have saved with this other method.  

As I entered that into my printing program,I noticed that it still scaled it down.

It seems that the dimensions are more correct other than the scaling.  I think this is more of an issue that I might have to address with Makerware.

Thank you for the extremely quick response.

[MariaManuela]

Thank you very much for your nice feddback

[kennycoulter]

I am back at it again....

We have recently updated to inventor 2018.  When I export the models for .stl, they are still resizing in a different way.

We model in "American standard dimensions".  I am making sure that I am selecting "inch" under the units option when "sending to 3d print service".


My models are still reducing in size when opening in both Makerware and RepG  slicing programs.

[johnsonshiue]

Hi Kenny,

A few things to try. Import the .stl file back to Inventor in an inch template. Does it shrink or it is correctly? If the measurement is correct, you will need to change the ipt document to mm and export it as mm (or document unit) to get the proper scaling. Please note that all mesh file format is unit insensitive. There is no concept of unit. I suspect the resizing in the printer is because the printer operates on mm, while the measurement in the mesh was taken in inch.

Many thanks!