Once upon a time, when I was a kid, making a Christmas card by hand was a great custom gift to give someone. How very 2D. Now it’s all about 3D printing, with my email full of suggestions for 3D printable gifts and decorations, and special discounts from the big 3D print companies like i.Materialise and Shapeways. So I had to do my own spin on the 3D printed gift, but rather than just show you the result, I’m going to walk you through step-by-step how you can download a design from your favourite file-sharing website, and customize it in 5 easy steps. Great if you’re short on time to design something from scratch, or if you’ve found something that already does exactly what you want and just want to add a little bit extra.
Step 1: Meshmixer Import
OK I’m assuming you’ve found a design you like on a website like Thingiverse, Pinshape, 3D File Market or Cults (they’re the ones I use anyway). For this example I’m using the Harley Davidson logo I found on Thingiverse, which is a great design since the designer RenatoT has already provided blank options without text, so it’s all set up to go. If you’ve got a design and you need to remove some details, either some text or a part of the design that you don’t need, check out a tutorial I wrote for my friends at Pinshape which explains how to remove features from a downloaded design.
For both requirements I highly recommend using Meshmixer, a free program from Autodesk which is very easy to use, and perfect for manipulating STL files. There are other programs out there (like MeshLab which I’ve written about previously), however Meshmixer is by far the best in my opinion, I use it regularly. When you have your file, just import it into Meshmixer.
Step 2: Design Your Addition
There are many ways you can create your addition – in fact you can use the tools within Meshmixer to edit the design and add basic forms including text. However I find them a little bit clunky to use, so I prefer to design my addition inside a proper 3D CAD program like Solidworks, or you can do the same in free software like 123D Design or Tinkercad, or whatever you have access to really.
The main thing is to get some basic measurements for where your text is going in Meshmixer first, which you can access from the Analysis>Measure menu and use the Point-to-Point option to measure the size of the face you wish to apply text onto. Turning on the Snap to Edges option helps, and in my experience you may need to try a few different options to get the measurement you’re looking for. For this Harley logo, the length I had to work with was 63mm, so I created a box in Solidworks to help visualise this. You can re-scale your design in Meshmixer later, but it really helps to just get it right from the beginning. Type in the text, adjust the dimensions to fit your bounding box, and extrude. Then export this file as a STL since this is the format used to import back into Meshmixer.
Step 3: Bringing It All Together
With your original file open in Meshmixer, you can now import the text into the same file. Make sure you select the Append option in the pop-up window so that both models will be in the same workspace. You will now have a new Object Browser window available to select between both files, shown on the right in the image above.
Obviously we now want to rotate and move the text into position. This is easily done from the Edit>Transform menu. Use the arrows to move the text, and the arcs to rotate it into position. As you get closer and closer, keep zooming in until you can push the text just inside of your chosen surface – if there are any gaps the 2 models won’t properly merge together and may have errors when it comes to 3D printing. If your imported text is too large or small, the little boxes at the ends of the arrows can be used to scale it as required. Click Accept when complete.
Step 4: Combine Into a Single Part
Just because your 2 models are intersecting on screen doesn’t mean they are actually joined together yet. If you look at the Object Browser window you will still see both models are separate. There are a couple of options to join them together in Meshmixer, and the options will pop up when you select both models together in the Object Browser (using shift-click) and then the Edit menu. We will use Combine, which will merge them into a single file as you can see in the Object Browser in the above image. For many 3D printers and software this is enough and you can export this now as a STL and get 3D printing (that’s all I did to print this design). However when you’re sharing files online it’s important to make sure your files are in the very best condition so everyone can 3D print them no matter what printer or software they’re using. And it only takes a few extra clicks to get this right. If you want to learn how just keep reading the next paragraph, however most of you will probably want to skip this detail for now as it’s a little more advanced and may not make sense.
OPTIONAL (Advanced): We can use Edit>Make Solid to properly merge the pieces together and also control the resolution of the mesh. The default settings may shock you when the preview is generated with a lot of your crisp edges becoming soft and low resolution. By increasing the sliders for Solid Accuracy and Mesh Density you can increase the resolution. Just click the Update button to refresh the preview model. When you’re happy with the detail you can Accept the model – just keep in mind the higher your resolution, the larger the final STL file size! In the Object Browser you will also note that the original model (before using Make Solid) is still available, just hidden from view so you can always go back to this one if you want to change the detail by clicking on the eye symbol.
Step 5: Export and Prepare for 3D Printing
Finally you are ready to use the Export function from the File menu. Make sure you check that the file type is a STL Binary Format, not STL ASCII Format which typically results in a much larger file size. This is the file to 3D print with, which you can see loaded into Cura above. You might also like to save in the native Meshmixer format (.mix) in case you want to come back and keep working on this file later – remember STL files are very dumb meshes so if you open your exported STL, you won’t have the same options to keep working on it.
That’s it, customizing your 3D print in only 5 simple steps with free software. With only days before Christmas, there’s still plenty of time to get printing!
– Posted by James Novak