CREO Parametric - Number of factets on an STL file

[YHAdesign]

Hi,

I use CREO Parametric 9.0 Student Eddition as a Hobbyist. When creating an STL file (Save as STL) for a 3D printer, I observe that the number of facets on circular srfaces is relatively low.

My question is : How to increase the number of factets, in order to get more precise circular surfaces ?

I foud this article in the CREO support, but it seems to be valid for another software : https://support.ptc.com/help/creo/ced_modeling/r20.5.0.0/fr/index.html#page/ced_modeling/OSDM_Main/Parts_23.html

Is there a limitation of the Student Edition ?

Thanks for your help

[MartinHanak]

Hi,

• set absolute accuracy in model
• set lower absolute accuracy value in model

[JB_87049]

Changing the absolute accuracy of the model won't change the number of facets.

I have created a video to show you how you can change the way the facets are generated.
The video is made in Creo 10. However, it is the same in other versions of Creo.

You can watch the video through the following link

https://technologiecampusdiepenbeek.be/PTC_Community/STL_facets-Creo_10.mp4 

I hope this will help you solve your problem.

Best regards,

     John Bijnens

[YHAdesign]

Hi John,

Thank you very much for your help ! It works perfectly and I can now specify the accuracy of my STM models.

Thank you for your reactivity 👍

Best regards,

Yves

[MartinHanak]

Hi,

attached video shows that absolute accuracy value sets lower limit for STL export.

[tbraxton]

@MartinHanak is correct in stating that the model accuracy can affect the tessellation as it sets the lower bound for chord height. If a given model had an accuracy that was so large it prevented features from tessellating with fidelity suitable for input to a process, then one would consider changing the accuracy of the model.

The lower bound for the chord height is a function of part accuracy while the upper bound corresponds to the model size.

In practice, I have never had to resort to changing model accuracy to get STL files suitable for even the highest end 3D printers. Our model accuracy is set such that it is tighter than the resolution of the printers so lowering accuracy would not yield better results from the printer.

[tbraxton · Accepted solution]

Chord height needs to be minimized to yield the best approximation of model geometry during tessellation. This will result in max number of facets when generating an STL.

Explanation of chord height:

Controlling the Quality of Export (ptc.com)

When exporting do the following:

Select the customize export option

Set the chord height to zero and Creo will minimize it with the lowest possible value for the model.

Set angle control to 1

[YHAdesign]

Thank you so much for your tip abd your reactivity., It works perfectly and now, my STL model are very accurate 🙏

Best regards,

Yves

[Michael]

Excellent answer I have this stored as a map key, and do it all the time.