Welcome

This is my home in the virtual world, where I write about things that I want to share. The freely available software that I've written as well as some of the photographs I've taken over the years can also be found here. Please use the navigation links on the right if you are looking for something.

Recent articles

1. M3 hexagon socket head cap screws and captive nuts in 3D FDM prints

   Inspired by my Prusa MK4S printer, I’ve been using hexagon socket head cap screws and captive nuts to assemble FDM 3D printed parts that might have to be disassembled.

2. Spool holder for 3 kg spools

   The spool holder on my MK4S printer is only suitable for spools of 1 kg filament. While these are fine for small prints, for larger prints it is preferable to use larger spools.

   Initially I used two support cradles where each to the rims of the spool runs on two roller bearings. This had some problems in that it tended to bind and then the spool could be pulled off the bearings. After this caused the failure of an overnight print job I wanted a proper spool holder.

   Not being satisfied by designs I could find online I designed my own, for spools up to 3 kg.

3. Kitchen scale repair

   After a couple of decades of use, the pointer on my Hema analog kitchen scale broke. This model is long out of production, and analog scales of this weight class (500 g) are kind of rare.

   Since I have a preference for equipment that doesn’t require batteries I wanted to repair it. This article documents how that was done.

   To be honest, if I didn’t have a 3D printer this repair might not have happened. The pointer is a small and delicate injection molded part with a wall thickness in the order of 0.5 mm.

4. Sharpening aid for DMT diamond whetstone

   Years ago, I bought a DMT diamond whetstone to replace a worn out ceramic whetstone. Since then I’ve been happily using it for freehand sharpening of tools and knives.

   While my freehand sharpening is OK, it is hard to get consistent angles when freehand sharpening. So when I got a 3D printer, I thought it would be nice to print a sharpening guide.

5. Dimensional accuracy of 3D prints

   In the process of determining the fit for a drill bushing, I measured the relevant dimensions of the test piece.

   The results were interesting enough to warrant its own blog post.

6. Drill bushings in 3D printed parts

   In order to make a 3D printed drilling jig last longer, I wanted to put drill bushings in it. Being new to 3D printing, I decided to print a test piece to see what the size of the holes should be for a snug fit.

7. First print on a Prusa MK4S

   My first print was a holder for a USB cable that I use to charge my cellphone.

8. Building the Prusa MK4S

   Buying a 3D printer had been on my mind for some time. The choice for the Prusa MK4S was driven by a couple of factors.

   • A printer designed and built in Europe is strongly preferred.
   • PrusaSlicer is free software is and available as a package for my operating system of choice (FreeBSD).

   As a mechanically inclined person, the choice for the self-build kit was a no-brainer. It’s like Lego for adults. :-)

9. Writing C in 2024

   To learn how it works and because I don’t use Java, I decided to port professor Michael Pound’s implementation of the Enigma machine and the fitness and analysis code.

   The initial port was done to Python. Unfortunately, this is one instance where Python was rather slow because of the large amount of settings that need to be tried.

   So I decided to port it to C instead.

10. Contact analysis of a pin in a fixed sleeve

    Inspired by a recent question at work, I looked at the stresses developing in a steel pin when it is loaded under bending and partially placed in a fixed sleeve.