Donald Papp developed a simple but loud alarm, "Mister Screamer", that is hanging from your filament and if the filament runs out it triggers a loud alarm.
Key features:
If filament is present, nothing happens.
If filament runs out, scream your fool head off to alert a nearby operator.
Enclosure can be 3D printed
Self-contained (no external power or signals)
Requires no modifications to the 3D printer to be monitored
Electrically simple, and using a minimum of easy to source parts
Since I live in deep rural Croatia surrounded with heavy agriculture, I often wonder abut my drinking water quality. Since a lot of pesticides and fertilizer are used we do have some issues with arsenic or nitrate pollution of water sources. Since water professional water testing is expensive and not the most accessible solution, I googled to see what can be done with hobby electronics and DIY approach. I found open source water quality testing platform and open source enzymatic-photometric nitrate testing system.
Both machines were developed by By Michigan Tech's Open Sustainability Technology like many other useful open source scientific devices. Casing and structural parts are 3d printed.
Detailed guides, software and manuals can be found at:
3D Proto, creator of dual parking extruder, made an excellent video about how to install and use inductive distance sensor with Mk3 aluminum hot bed. This combination enables you to reach much better quality of ABS prints. With inductive distance sensor bed leveling you can:
Save lot of time by not having to have to mess with springs and screws on your print bed. Run the auto leveling routine before every print or just one time for each start-up of the printer.
Less issues related to non level print beds like parts coming up on one corner and nozzles jamming because the print started too close.
Inductive distance sensors are very cheap so it makes me wonder why are they not used by more 3d printers for automatic bed leveling? If you wont to see full guide on how to install and use it with Marlin go to:
Here is a collection of filament diameter (width) sensors for your 3d printer which will enable you to compensate for variations in filament and get better print quality. You can make them with some basic electronics skills.
Thomas Sanladerer designed, printed and tested this filament diameter sensor. It could be used on filament making extruders as a control sensor, or in 3d printers to get better printout results. The work on it is in progress, further accuracy improvements are needed but the current results look promising.
This is a proof-of-concept filament diameter sensor, currently intended for an extruder making filament. The filament centerline is 90mm above the mounting surface. It picks up the filament's diameter between two bearings, amplifies it via the lever by a factor of 3.6, which moves a magnet in front of the hall sensor. The hall sensor's depth is adjustable and is locked into place via the M3 bolt. Bend the hall sensor's leads 90° to the back and place the sensor in recessed spot. Lead the wires out to the front.
The 6x2mm magnet goes into the matching hole in the lever. The second hole intended for a ballpen spring, which is not needed in most use cases. For testing, upload the included sketch to an Arduino, connect the hall sensor to 5V, ground and hook the signal pin up to A1 on the Arduino. Connect via serial at 115200 baud, it will start spitting out two values each line, the first one is the smoothed ADC value, the second one the calculated diameter.
To calibrate, insert a test object with the maximum diameter you want to measure between the bearings and move the hall sensor carriage until the ADC value just reaches a maximum. Lock the carriage in place and use that value along with the diameter of the object as the last entry in the Arduino's lookup table. Insert two (or more, if you increased NUMTEMPS) more objects of varying sizes (for example the shafts of drill bits) and fill out the lookup table. Use the idle position without anything inserted for the zero-diameter position.
Support might be required for the files as they contain 30° overhangs. If you use Slic3r, you're better off with no support material.
Here is a different project which is more heavily developed and has extensive video tutorial: the Filament Width Sensor by flipper for Lyman extruder or stand-alone applications with a voltmeter
Width sensor project description:
The idea is that with a real-time width measurement the 3D printer could compensate the extruded flow for changes in filament width. Also if there is variation between spools of filament, there is no need to calibrate for that when slicing. The g-code is independent of the filament diameter.
For filament extruders, the measured width can be used as feedback in the extrusion process.This version includes a custom designed pc board as well as a housing. A version of Marlin is modified to use the sensor data.
The sensor outputs a voltage in milimeters (3v=3mm) that is shown on the voltmeter. I made some changes to Marlin to read the filament diameter real-time and compensate the extrusion rate. Code uses a buffer to manage the transit delay between the sensor measurement and the nozzle.
All the files, code and instructions can be found at:
There is a version of a diameter sensor based on hacked digital calipers developed by Wei-Hsiung Huang. It has several issues related to digital caliper precision and internal workings but it is a good learning project with some usefulness.
You can find all the instructions, code and build guide at:
You can download the design files and cut the beehives on a CNC machine.
From project webpage:
The Open Source Beehives project is a collaborative response to the threat faced by bee populations in industrialized nations around the world. The project proposes to design hives that can support bee colonies in a sustainable way, to monitor and track the health and behaviour of a colony as it develops.
Each hive contains an open source sensory kit, The Smart Citizen Kit (SCK), which can transmit to an open data platform: Smartcitizen.me. These sensor enhanced hive designs are open and freely available online, the data collected from each hive is published together with geolocations allowing for a further comparison and analysis of the hives.
Printing technologies are expanding further. SenSprout is a device for monitoring air and soil moisture in order to optimize agricultural production and irrigation management. It is produced by printing the electronic circuits on paper with silver nanoparticles. It is powered by ambient radio frequencies (it harvests 2,4 GHz frequencies) and transmits data on same frequency. I wonder how practical it would be for real life application since it looks fragile, it is currently deployed and tested. Even if not practical, concept is excellent technology demonstrator: downloadable printable sensors powered with surround electromagnetic radiation. Cool! They use commercially available inkjet printers and commercially available conductive ink from Mitsubishi. Project by: Yoshihiro Kawahara
Applications of 2d printed electronic circuits are infinite, similar to 3d printing. Hopefully this technology will soon expand into DIY space. There are many corporate and academic developments in conductive inks, but conductive ink can be also produced in DIY / home lab setting (this one doesn't work on paper):
