3D-printed caps for protruding bolts

When I attached our children’s swing to the ground there was still a significant piece of sharp-ish threaded metal sticking out above the bolt head and I was worried about them falling on it. Grinding the end off might still leave some sharp parts, so I thought it safer to print plastic covers for them.

I designed the caps with OpenSCAD, using the ScrewsMetric library for the bolt-shaped inset.

You can see the source code for Continue reading

3D modelling replacement knobs for back massager

small wooden knob

small wooden knob

There’s this fantastic device we have at home that I’m fairly sure is for giving back rubs, or maybe massages in general, like on your legs or something. I’ve tried it a few times but mostly the kids play with it. However it bothers me that there’s holes in it where the little knobs are supposed to be, so it doesn’t roll properly. I think the kids pulled them out, but maybe Continue reading

3D Printed Hungarian Cross

The Hungarian coat of arms features an iconic cross with two horizontal beams. In Hungarian it’s called “Kettős Kereszt” which translates to “Double Cross”, usually called the Patriarchal cross in English. This cross is present on other emblems around the area of Central and Eastern Europe too and has been featured on the Hungarian coat of arms at least since the reign of King Saint Stephen of Hungary.

3D model of the patriarchal cross as shown on the Hungarian coat of arms

3D model of the patriarchal cross as shown on the Hungarian coat of arms

Seeing as it’s a Hungarian national holiday today, in memory of the heroes and martyrs of the Hungarian revolution of 1956, everyone has their Hungarian flags out. I decided to do something Hungarian too, while trying out some tools for preparing models for 3D printing. So far I’ve been using Blender, because I have some experience with it, but it’s for creating 3D scenes and although you can use it to design 3D models for printing, it’s not CAD software. This time I tried Autodesk’s web-based program Tinkercad, which although lacking many of the features you’d get in a full-blown CAD program, is plenty enough for me to design simple things like this. Not being a mechanical engineer, I probably wouldn’t even know what features I’m missing!

photo collage of 3D printed "Kettős Kereszt" painted in the colours of the Hungarian flag

3D printed “Kettős Kereszt” painted in the colours of the Hungarian flag

The program is very intuitive to use. I put a few cubes on the workplane, stretched them out into intersecting rectangular boxes and exported an STL file for printing within minutes. You can see a screenshot of the result above. I also made a version with a hole cut out of the top so you could hang it on a key chain. That turned out to be as easy as putting a cylinder in one of the boxes, stretching it out of the top and bottom box faces and marking it as a “hole” in the model.

After scaling the model down to 30% so it fits on my print bed, the final print came out as shown in this photo. It took less than 10 minutes to print at 30% in-fill and seems pretty rigid. I’ve painted on the red, white and green of the Hungarian flag and will hang this up somewhere, who knows, maybe it’ll even be good for a Christmas decoration. If you’d like to print your own Hungarian cross you can download both of my STL files here:

In honour of the heroes! Tisztelet a hősöknek!