Smoothing curved output from Tinkercad

[Paul_H]

One of Tinkercad’s annoyances is that curves and circles are represented as multi-faceted stepped surfaces, not true curves. Files exported as STLs for printing retain this unhelpful geometric design.

However I’ve just stumbled on a way to avoid this entirely and get pure curves that I haven’t seen documented elsewhere;

You’ll need a copy of Fusion 360 installed (available for free use, subject to licence).
When you’ve finished designing in Tinkercad, instead of exporting in stl or obj formats, use the ‘send to’ command. The file is then sent to Fusion 360 where it arrives as a fully editable design. You then just save the file, which allows you to export it in your chosen format (stl, obj etc). (You need to save it in Fusion for exporting to be an option.)
You can get the benefit of this without any significant knowledge of Fusion, other than ‘save’ and ‘export’.

The other great benefit of this workflow is that the design in Fusion remains properly editable for those that have some basic knowledge of Fusion. This allows you to utilise some of functions in Fusion that are easy to use, eg chamfer, fillet, cove, threaded holes etc that are hideously complex(impossible?) in Tinkercad, but simple to use in Fusion.

The one annoyance is that this workflow won’t work with structures not built from Tinkercad's primitives (basic shapes). So if you’ve used shape generators or imported pre made designs and edited them you can’t send them out to Fusion.

 

[adrian]

One of Tinkercad’s annoyances is that curves and circles are represented as multi-faceted stepped surfaces, not true curves. Files exported as STLs for printing retain this unhelpful geometric design.

However I’ve just stumbled on a way to avoid this entirely and get pure curves that I haven’t seen documented elsewhere;

You’ll need a copy of Fusion 360 installed (available for free use, subject to licence).
When you’ve finished designing in Tinkercad, instead of exporting in stl or obj formats, use the ‘send to’ command. The file is then sent to Fusion 360 where it arrives as a fully editable design. You then just save the file, which allows you to export it in your chosen format (stl, obj etc). (You need to save it in Fusion for exporting to be an option.)
You can get the benefit of this without any significant knowledge of Fusion, other than ‘save’ and ‘export’.

The other great benefit of this workflow is that the design in Fusion remains properly editable for those that have some basic knowledge of Fusion. This allows you to utilise some of functions in Fusion that are easy to use, eg chamfer, fillet, cove, threaded holes etc that are hideously complex(impossible?) in Tinkercad, but simple to use in Fusion.

The one annoyance is that this workflow won’t work with structures not built from Tinkercad's primitives (basic shapes). So if you’ve used shape generators or imported pre made designs and edited them you can’t send them out to Fusion.

Again to be totally pedantic ( not in my nature at all! ) we are using digital computers so it will it will always be a faceted stepped surface to some degree for a curve. You just need to adjust the resolution so that you can no longer distinguish the steps, the closest you can get is to convert to vector format and bezier curves, but as the screen you are using is digital it will still be a stepped surface.

Personally I don't use Tinkercad but I would hope that there is a "preference" which you can adjust to change the display rather than resorting to Fusion 360. I use FreeCAD and that has an option to reduce the stepping on curves (2D and 3D) from

FreeCAD: How to smooth circel and arc in sketch? - XSim

When you draw circles or arcs in sketch, they will be displayed as coarse approximated shape with lines. The approximation is designed to display the curves faster on low spec computers. But if you want, you can change the settings to display the curves smoothly.

www.xsim.info

 

[simond]

Yep, even the high end commercial programs (eg Solidworks & Creo) do it on screen.

 

[Paul_H]

Again to be totally pedantic ( not in my nature at all! ) we are using digital computers so it will it will always be a faceted stepped surface to some degree for a curve. You just need to adjust the resolution so that you can no longer distinguish the steps,

Yes, of course, I know all that. The problem with Tinkercad is that the best 'resolution' is rather coarse. This is integral with Tinkercad because it's not designed as a precision tool, but as easy, fast software to use to learn CAD. An annoyance is that the numbers of 'steps' as Tinkercad calls 'resolution' always defaults to the minimum. If you work fast and forget to raise the step count on one part it can be awkward to reverse back through a design to change that setting for a particular body.

Personally I don't use Tinkercad but I would hope that there is a "preference" which you can adjust to change the display rather than resorting to Fusion 360.

This isn't just a display issue, it's the final stl output that has the faceting and that shows on the actual prints.
Once you pass files to Fusion that coarseness is eliminated and the prints can be far more acceptable.

A lot of people do use Tinkercad for making models because it's so simple and quick to learn, rather than having to spend large amounts of time learning complex professional 3D CAD software. Many will have tried Fusion and given up, beaten by the difficulties of understanding it's nuances and peculiarities. However some of that learning can be utilised relatively easily when a Tinkercad model is sent to it. As mentioned in the first post that includes some functions that are hugely difficult in Tinkercad, but trivial in Fusion.

 

[Brian McKenzie]

Tinkercad limits the size and resolution of STL files apparently, ignoring enhanced screen display settings.

This video suggests making use of other software - as Paul_H is doing.

I wonder when we shall see slicing software working directly from 3D CAD files - without the need for an STL version in between?
Slicers presently create G code for 3Dprinters by jogging over an interim bunch of triangles.
CAM software converts 3D CAD directly and smoothly into G code for CNC machines, so why shouldn't slicers accomplish the same thing?

 

[Paul_H]

Tinkercad limits the size and resolution of STL files apparently,

Yes, for software primarily aimed at schools, it's no great surprise it has some limitations. For a lot of model work those restrictions aren't significant.
Editing pre-made STLs isn't Tinkercad's strength either.

This video suggests making use of other software

Maybe a clumsy way to do that particular task. The idea of pre-making elements in other packages to import into Tinkercad is interesting.