Ergonomic Hacksaw Grip

I designed this 3d-printable hacksaw grip that accepts a standard 12mm / 1/2 inch wide metal hacksaw blade. It’s very useful to get into small spaces and for flush cutoffs. Last but not least it allows to recycle broken or partially worn blades.

The blade is mounted best to cut in pull direction like a Japanese wood saw, this helps to straighten the blade while cutting.

The STLs are on thingiverse, Fusion360 sources on github.

OctoPrint Plugin for Klipper

I made a OctoPrint plugin for the Klipper 3D printer firmware. It’s on GitHub at:

Features so far:
  • Simplified connection dialog.
  • Restart Host and MCU processes.
  • User defineable macro buttons.
  • Assisted bed leveling wizard with user definable probe points.
  • Dialog to set a coordinate offset for future GCODE move commands.
  • PID Tuning Dialog.
  • Message log displaying messages from Klipper prepended with “//” and “!!”.
Some screenshots:

Open Source Brushless Servo

The odrive is a open source high performance brushless servo platform based on RC BLDC motors. Great Stuff!

Key Specs

  • Two motor channels.
  • 24V, designed for more than 100A peak current.
    • 48V version just released.
  • DC-DC converter, for brake resistor or energy storage.
  • Encoder feedback for arbitrarily precise movements.
  • Supports power regeneration.
  • Optional use of a high power density battery means you can achieve >1kW peak power output with only a modest power supply.
  • Open source: HardwareSoftware


  • USB Serial port — PC, BeagleBone, RaspberryPi, etc.
  • CAN — CANOpen and CiA 402 is a possibility.
  • UART — Arduino, mBed, etc.
  • PWM — RC Recievers, Arduino, etc.
  • Step/direction — Existing motion controllers
  • Some general purpose digital and analogue pins


  • Many types of command modes
    • Goto (position control with trajectory planning)
    • Position commands
    • Velocity command
    • Torque command

HowTo Enable the RaspiCam in Octoprint

First, if you haven’t already, activate the camera in raspi-config. Login via SSH type “sudo raspi-config” select “Interfacing Options” and enable the camera.

Configuring the camera

Now edit “sudo nano /boot/octopi.txt” uncomment the camera=”auto” line and change it to camera=”raspi”. Uncomment camera_raspi_options=”-fps 10″. These settings configure the camera to provide and image in the format 640×480@10fps. If you would like to change that check the available options in the official forum:

Enabling the camera in the octoprint browser interface

In the browser click on the little wrench in the top bar to open the settings dialog. Select “Webcam & Timelapse”. Set the “Stream URL” parameter to “http://octopi.local:8080/?action=stream”. Obviously change the hostname if you have configured it to something different.

Finally restart octoprint for the changes to take effect.

HowTo build the Marlin 3D Printer Firmware on the Raspberry Pi

If you are already running the excellent octoprint as a printserver on a Raspberry Pi it is very convenient to also build Marlin on it. The new Raspberry Pi Zero W with onboard wifi is at only 10$ just perfect for both tasks. If you want to use the camera streaming of octoprint I would recommend a Pi3 though.

I made a script that sets up the necessary build environment and provides commands for building and uploading. It uses the official Arduino toolchain. Everything is standalone, nothing is installed outside the marlintool directory.


here on github:

or download directly as a zip:

Build configuration

Before first use: Rename the marlintool.params.example file to “marlintool.params”

In its default configuration the script is setup to build the official “Marlin” firmware  but can be easily reconfigured to build any Marlin variant.

Several additional parameters in the “marlintool.params” file allow to adapt the script to your needs.

parameter description
marlinRepositoryUrl The marlin git repository.
marlinRepositoryBranch The branch of the configured repo to use.
marlinDependencies A list of dependencies to download in the format:
[name],[repo url],[library directory](optional).
A library directory should only be specified if the library is not in the root of the repository.
hardwareDefinitionRepo If you build for the Anet board this downloads the necessary hardware definition for the Arduino build environment. If you dont need this set it to an empty string.
boardString The Anet board identifier.
arduinoToolchainVersion The Arduino toolchain version to use. The build platform and architecture are auto detected. At the moment Linux 32 Bit, 64 Bit, ARM and OS X are supported.
port The serialport to use for uploading.
arduinoDir Where to put the Arduino toolchain.
marlinDir Where to checkout Marlin sources.
buildDir The build directory.

Reminder: If you are running octopi on you Raspberry you need to disconnect it from your printer before uploading, otherwise the serial port is blocked.

Note: On OS X due to how the Arduino toolchain is packaged the Arduino splash screen will be displayed even when the toolchain is used from the commandline. This will cause the terminal window you launch marlintool from to lose focus. It also means that a build cannot be launched from a remote ssh session.

Building for Anet Hardware

If you are building the firmware for the Anet A6/A8 you can find suitable example configurations in the Marlin sources at: Just replace the “Configuration.h” and “Configuration_adv.h” in the marlin directory with the files your find there for a good starting point of your configuration.


Commandline parameters

-s  — setup

Download and configure the toolchain and the necessary libraries for building Marlin. Also fetches the Anet board hardware definition from github if specified.

-m  — marlin

Download Marlin sources.

-f –fetch

Update an existing Marlin clone.

-v  — verify

Build without uploading.

-u  — upload

Build and upload Marlin. If you are running octopi on you Raspberry you need to disconnect it before uploading otherwise the serial port is blocked.

-b  –backupConfig  [name]

Backup the Marlin configuration to the named backup.

-r  –restoreConfig [name]

Restore the given configuration into the Marlin directory.

-c  — clean

Cleanup everything. Remove Marlin sources and Arduino toolchain.

-p  — port [port]

Set the serialport for uploading the firmware. Overrides the default set in the script.

-h  — help

Show help.

Browserbased 3D CAD is a parametric 3D CAD solution for the web browser powered by coffee script. It’s currently in its early development stages. Still interesting if you think of online 3D printing.

Another CAD solution for the browser is the javascript based openjscad.