Editing STL Files

[HO RacePro]

It is a great thing that we can download printable STL files from sites like Thingieverse and Cults3D. Problem is said files are rarely exactly what we want, and STL files cannot be edited in most CAD programs.

Just yesterday I downloaded an STL of a "Sting GW1 CanAm Racer"from Cults3D. The prototype is a McLaren specially built for a privateer team in 1974. It appears to be exceptionally suitable for a slotcar body. And it looks like it could be printed nicely, except the rear wing will need to be supported, and that is likely to mess up the rear deck of the body. So I am looking to remove the rear wing and print it separately. But I can't do that in my existing CAD program.

After some research online I found that an AutoCAD product known as "Tinkercad" is supposed to be able to edit STL files. Having looked at some YouTube videos Tinkercad looks completely capable of doing the editing I need. It helps that it is freeware and appears relatively simple to learn.

Has anybody here used Tinkercad to edit STL files? How did it work for you? Or are there other such programs available that you like better?

[MrFlippant]

Fusion360 can import STL files. They're called "mesh" files, so that's what the import tool is called. You then need to use the Mesh tools to create face groups and then convert the mesh to a solid to edit it. You can also do some editing with the Surface tools. If Fusion is your CAD program, it's worth learning about those tools.

That said, it's not an ideal STL editor, especially for complex mesh bodies like a car body, with hundreds of thousands of vertices to deal with. Simpler STLs are much easier to convert and edit in Fusion.

For the complex ones, many people turn to Blender, which is designed to work with mesh files to begin with. I don't use Blender, but I've seen some amazing things done with it.

[Bal r 14]

I vote for Blender. I used it a lot for 3D modeling, back in my game developer days.

[Kevan]

You could ask Chappyman if he has the wing as a separate file.

Failing that separate the wing using the 'split' tool in something like 3DBuilder.

[Junior]

I use TinkerCad for re-sizing of files, creating basic design and minor editing like you are describing. I am not a CAD person, but it is fairly easy to use. When can't figure out how to do something in TinkerCad, I usually can find a how-to video on YouTube. I have run into issues with some the the limitations when importing a file, either due to the size of the file or the number of surfaces that an object has. Not sure of the exact limitations.
Tom

[chappyman66]

TinkerCAD is limited to 25MB or 300,000 triangles depending on the file. However, the Sting GW1 shouldn't be a problem since I did the wing edit in there (the original file was of course a -nimrod- creation).

If you print the car tail down, you don't need support like that (that's how I printed mine) but TinkerCAD should let you separate the wing if you prefer.

[HO RacePro]

I haven't tried printing a body tail-down. I've always thought it would not be stable enough. Have you had any success doing that?

[HWPSlotCars]

I use Blender (http://blender.org) for most 3D modeling. Extremely powerful, though like most 3D packages, its initial learning curve can be quite steep. It can easily import STL files. Problem is, most STL files I've looked at on thingiverse are generally not designed for slot car use. And the STL file format usually converts mesh faces to triangles which makes the meshes a lot harder to smoothly edit. There are a number of websites that offer free models in various native formats, including ".blend" files which will usually be much easier to work on as they often aren't triangulated yet.

[chappyman66]

I have printed a number of bodies tail down and posted several threads and pictures about it over the last two years.

Blender can be very useful, but as with many packages the learning curve is steep. There is lots of help and tutorials for those wanting to learn.