Jump to content
robwal

opening STL from openscad strange scaling

Recommended Posts

Posted · opening STL from openscad strange scaling

Hi There!

I'm a bit new to 3d printing, but already love it! Printing downloaded stuf is going smooth but I want to design my own ;-)

 

I have made an simple object in openscad wich I export as stl file and then open in Cura (lates 3.4.1).

The problem is that cura scales the object extremely and I can't figure out why.

 

In openscad I use the following code:

 

            cylinder(0.1, 0.1, 0.1);

 

When I make a cube all goes well.

 

Any help is welcome an thanx in advance!

Rob

Screen Shot 2018-08-02 at 16.21.31.png

Share this post


Link to post
Share on other sites
Posted · opening STL from openscad strange scaling

Hi Rob and welcome to the forums.

 

The reason Cura scales the cube is because of its tiny proportions. You have set the cube to be a tenth of a milimeter big. Check out these Cura settings (and you might want to create a bigger cube ? )

Screen Shot 2018-08-02 at 16.38.36.png

  • Like 1

Share this post


Link to post
Share on other sites
Posted (edited) · opening STL from openscad strange scaling

Hi Nicolinux!

 

Changed it!

I'm having similar (??) problem with the STL generated from following openscad and then opening in Cura.

 

difference(){
cylinder(h=30, r1=60, r2=54);
    cylinder(h=30, r1=7, r2=7);
}

I'm trying to print a cap for the filament side gap.

It is a 3cm high cap for both ends, it has a 7mm hole in it.But it turs out real big...

 

I hope you can guide me towards the solution!

Kind regards,

Rob

Screen Shot 2018-08-02 at 16.43.39.png

Edited by robwal

Share this post


Link to post
Share on other sites
Posted · opening STL from openscad strange scaling

Hi,

 

this looks about right. You speficied "cylinder(h=30, r1=60, r2=56)". "r" stands for radius, so it has a diameter (r*2) of 120mm. Cura does not perform any automatic scalling now and you can see that the object is 30mm tall.

Take a look at the OpenSCAD documentation for cylinder:

https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/The_OpenSCAD_Language#cylinder

 

One more hint - play with "$fn" which specifies the smoothness of the object (facet number). This way you'll get smoother curved surfaces.

Share this post


Link to post
Share on other sites
Posted · opening STL from openscad strange scaling

Don't go much smoother than this - maybe 4X smoother.  If you go too smooth there are too many points and the printer does very poorly when there are more than 5 points per mm as it is moving.  It can only look ahead 16 points and if that is less than a few mm it slows down just in case it needs to stop on the 17th point.  Slowing down causes overextrusion and ugliness.

 

I love openScad by the way.

Share this post


Link to post
Share on other sites
Posted · opening STL from openscad strange scaling

Thanks for the tip GR5! I might nock (twice) on your door for advice one of these days ?  

 

Rob

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Our picks

    • Ultimaker Cura 4.0 | Stable available!
      Ultimaker Cura 4.0 is mainly focused on the improved user interface and cloud integration.
      As always, we want to collect your user feedback for this release. If there are any improvements you can think of, feel free to mention it here and help us to shape the next release.
      • 19 replies
×
×
  • Create New...

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!