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
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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.
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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.
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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.
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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.
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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.
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My first print was a holder for a USB cable that I use to charge my cellphone.
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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. :-)
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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.
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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.
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This is the fifth in a series of articles that covers analyzing and improving
performance bottlenecks in Python scripts.
The program calculix-orient is a helper program that automates the asignment
of local coordinate systems for anisotropic finite elements.
It is designed to work together with CalculiX.