Concrete CNC Router

CNC router cast from UHPC concrete with linear rails and 4th axis
CNC router cast from UHPC concrete with linear rails

I started designing a CNC router. The bed and beam are supposed to be cast from UHPC (Ultra High Performance Concrete) [german]. This is a very dry concrete mix with aggregates that increase its mechanical strength, and a plasticiser that makes it viscose enough to be usable for casting again. The end product can achieve mechanical properties comparable to aluminium and has very good vibration dampening properties.

If you’re interested in some of the basic things to consider when designing with concrete, check out this great series on the topic by the “Practical Engineering” channel on youtube.

The design uses 20 mm linear rails all 600 mm long. Ball screws on X and Y are 16 mm SFU and 12 mm SFU on Z. All bearing blocks are standard BK/BF style. Motor flanges are NEMA23. Drawn are JMC iHSV57 servos. The design would also allow to use steppers geared down with pulleys.

Design Notes

The main idea behind the bowl shape is to create a partially enclosed volume that allows to use flood coolant without creating a mess. It also raises the y-rails to an optimal height.

All bearing surfaces are metal pads that are glued into the finished casting and anchored with pins. This allows to achieve high position and alignment accuracy without the need for a large mill. If a mill would be available, milling the bearing surfaces after the glue-up would be ideal.

The port holes in the side are mounts for an optional 4th axis to enable mill turning. They also allow to attach dust extraction when milling wood and double as an all purpose bulkhead.

Two threaded rods put the beam under compression along the x-axis to increase its strength.


Touch Controller

CNC Controller with Touch Display
CNC Controller with Touch Display

Benchtop Power Supply Housing

3D Printed DIY Benchtop Power Supply
3D Printed DIY Benchtop Power Supply

This is a housing for a benchtop power supply using the “MingHe B3606” CC/CV module. There are several variants of this module, this is for the 36V/3A 50x66mm version.
It utilizes a Siemens SITOP PSU100S DIN Rail Power Supply as a DC source. And yes, if you have to buy the Siemens supply new this build is not really economically viable. But as these are often available used on ebay for a reasonable price this might still be interesting for some.

Other DIN supplies might fit as well. The dimensions of the used supply are: 70x126x126 mm.

There are three through holes for binding posts. I decided to use the 3rd to lead out the unregulated 24V/10A from the Siemens supply. Alternatively this position could be used for PE.

3D Printed DIY Benchtop Power Supply


The printing should be straight forward. Support is required at least for the front cutouts of the module as these need to be quite precise.

The feet are ideally printed with TPU. An alternative that provides very good grip, is to cut fitting pieces of silicone rubber hose and press them in.

The light-guides for the modules LEDs are not strictly necessary but make them less directional. Print with transparent PLA or translucent white.

For the raised lettering on the buttons I switched materials from black to grey during printing.


In addition to the printed pieces you will need:

  • Three insulated binding posts.
  • A switched and fused IEC socket and two screws to mount it.
  • Two short M3 screws to fix the power supply module with the supplied frame to the housing. The screws that come with the module should work for this.
  • Cabling.


The files are available here: Benchtop Power Supply

Happy Printing

TinkerSoup – Berlin based electronic kitchen

The Berlin based electronics online shop TinkerSoup is reselling electronic components of lots of tinkerers favorite companies: 4D Systems, Fritzing, Olimex, Pololu, Sharp, Smart Projects, Spark, Fun, ThingM, USGlobalsat, Adafruit

Seems the domain was sold to UK based Pimoroni

A great shop for tinkerers in Berlin is sertronics they sell online but have also a brick and mortar store. They are also an official raspberry reseller.


DiY Sci-Fi Short

A sci-fi short filmed by a Scottish art director has become what The Hollywood Reporter calls the “year’s first hot short.”

 Craig, 37, used the short film, titled Modern Times, as an exercise in on-the-job training. The DIY filmmaker “relied on the goodwill of friends, with the ultimate cost of the short being sandwiches and pints at the pub,” according to the Reporter’s Heat Vision blog.

Watch Modern Times and you’ll see a quiet, visually impressive meditation on the future. There are no exploding spaceships, no blue aliens and no lasers. And the decision to skip dialog and go with an operatic soundtrack definitely classes up the clip.

The short film has generated interest from studios including Warner Bros, Fox and Paramount, according to Heat Vision. A behind-the-scenes clip, embedded below, shows how Craig pulled off his Hollywood hit.