Two STL files for colour printing text on an existing model

TomicoTom · September 9, 2020

I want to be able to add the name of students on to their completed 3D models and then quickly and easily create two TL files, one of the original model and the second with the text split out so that we can print their work with their name on it in a different colour. We are using an Ultimaker 3.

We have been trying different methods and keep trying Meshmixer but what a time consuming performance that is..

I can add the text to any contoured surface of an existing 3D model quickly and easily with almost any basic or even free software but then I have to open the 'merged' file (original model with the text) in Meshmixer and mess about for ages trying to split it all out again to create the two STL files required for printing in two colours.

In my mind it seems I am missing a simple but very logical step.

I have the original 3D model, the text has been applied so the software knows exactly what the text is and on to which surface it has been placed. so if the option were available at this stage it would be a trivial matter to simply produce the two STL files needed for two colour printing, one of the original model and one of the applied text

Does anyone know if there is any such software available?

geert_2 · September 9, 2020

In your CAD-software, can you hide parts of a complex model?

For example in DesignSpark Mechanical (=free but requiring registration, and only suitable for geometric models, not for organic life-forms): as long as the parts are not merged, I can simply hide each by unchecking it. And then make it visible again. This allows exporting each part separately.

Let's say you have a cookie-cutter mould, named: "cookie", and the kid's name written on it: "kidname". Then I could hide "cookie", and save "kidname" separately as a model, or export to STL. And then I would make "cookie" visible again, but now hide "kidname", and save that as second model or STL. This should achieve what you want, if I understood it correctly? But this obviously requires that the parts are not yet merged into one single object in CAD. It should all be separate parts.

I use a somewhat similar method to add text to a model, in such a way that I can easily reposition or alter it later on. And I only do the merging (required for my single-nozzle printers) at the very last moment upon exporting to STL.

See this pic. This was for designing internal watermark text, shining through semi-transparent materials, but the idea is the same. Don't merge, export each part separately.

TomicoTom · September 9, 2020

Thank you for your reply, I have downloaded DesignSpark Mechanic as suggested but tI can see no obvious way to insert text to the opened model that needs the text added to it?

geert_2 · September 10, 2020

There is no official text feature, at least not in the version I have (maybe in the newest or beta-versions?). DesignSpark Mechanical is a free but limited version of the commercial and expensive SpaceClaim. But there are 3 ways around it:

1. Use the Dimensioning tool. This is the tool which draws measuring lines and arrows and dimensions like this:

<-- 3.0mm -->

Measure a dimension where you want text. So, now you have this: <-- 3.0mm -->. Then delete the numbers and arrows, and replace them with your custom text, in a font you want. This text is still sitting in the dimensioning plane, not on the model. Then project the text onto the model, using the project-tool. And extrude as desired. On the DesignSpark Mechanical forum, user Jacant has made a good tutorial of this method with lots of pics: search for it.

2. Set the text in SketchUp. But SketchUp is notorious for geometry problems due to vectors and faces not closing (=they are like poor cartboard models, not solids). Thus repair any open vectors by moving the endpoints until they snap together and can be filled. Export this text. Import in DesignSpark Mechanical. Extrude and move around as desired.

3. Design your own font in vectors, directly in DesignSpark Mechanical, like I did. This is no real font, but just separate character-items. However, they are optimised for 3D-printing small text. Copy and paste them from the font-file to the desired location. This is similar to text-setting in cast lead letters in very old books. This is the method I use most. Obviously this is not suitable for making 3D-printed newspapers, but for occasional text like a watermark or part number, it is good enough. Later Jason Chall has made a real font out of my DSM-font, so you can use that font for technique nr. 1 above. For the files, see here (and then scroll down quite a bit):

https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/

However, maybe you do not need DesignSpark Mechanical, and you can use that technique in your existing CAD-software? Most that I have seen, have that capability to hide elements by unchecking them in the model-tree, or by right-clicking on them and choose "Hide" or so. Be sure to save your design and make backup copies, before experimenting.

A few examples of text set this way (with my font file, method 3). All characters are 3.5mm caps height, and legs are 0.5mm wide. Some are watermarks (=hollows), some raised normal text.