Lair Of The Multimedia Guru

July 31, 2018

3D printer particles / air pollution

A while ago i read about 3D printers spewing out nano-particles into the air, especially ABS. I was curious if i can actually measure this on my own printer and how to fix it.
My plan was to use a cheap air quality detector, that i bought previously. It has to be noted here that the device detects particles 300nm and larger while what i read seems more about 100nm and smaller particles so its not 1:1 comparable.
Before anything i used my vacuum cleaner to very roughly remove large visible crap from the inside of the printer enclosure.

First baseline measurement, with the printer on, no heating yet.


Can we reduce that particles/dust ? Lets try properly cleaning the enclosure with the vacuum cleanerto use a stream of negative ions to ionize the particles, so it sticks to something and doesnt stay in the air. As can be seen this is a effective way to clean the air, or the measurement device is affected by the ions.


There is a slight disadvantage, in that it seems the well designed printer (which lacks grounded components). Has its metal frame charged up by the ions and that then eventually discharges into something …


Luckily no permanent damage is done and a reboot of the printer clears this. Until it quickly happens again. But after a few minutes all the particles appear to be eliminated


Adding a wire between ground and the frame (with a 1k resistor between) stops it from charging up and seems to resolve this problem.


Next after heating up the heatbed to 65°C without the ions. There is really alot of particles/dust in the air of the enclosure:


After also heating up the nozzle to 215°C with PLA in it:


After finishing the print 38 minutes later


Waiting 30min (the heatbed is not disabled by the printer, the nozzle cools down), there are still significant particles in the air


Switching the negative ion generator on, 5 minutes later the particles in the air have decreased significantly


Another 5 minutes later the particles are largely gone


Now question, what happens if we try to print with the thing on?
First opening the printers enclosure brings some of our particles/dust back (from the airflow caused by the door presumably). After all it didnt magically disappear and theres nothing that would truly capture it (the heatbed is at 65°C here)


After the nozzle heated back up to 215°C the particles actually decreased


Taking an image every minute from the air quality meter shows that within about 6 minutes after the print started the particles go to 0, it does rebound slightly and fluctuate around 0 after that.


The print finishes without problems after 36 minutes. Originally i intended to repeat this with other filaments but as the biggest dust/particle creator seems the heatbed or rather air convection from its heat. This would need to be setup differently to eliminate that. As it drowns out new particles from the heated filament. But still this shows that for less than 4 euro shipped one can get a device to eliminate at least larger particles from the air within the enclosure of a 3d printer. Compared to a filter this is probably easier to setup as well. Further experimentation would definitely make sense. Though simply having an enclosure and opening it together with a window for 5 minutes probably removes most particles, if one is concerned about it.

Filed under: 3D printer — Michael @ 21:04

July 14, 2018

Chinese worklight repair

A while ago i bought a quite cheap flashlight/”worklight” from aliexpress. Not the best quality but it worked.

About 3 days later its button started to work only intermittently. A few days later it basically didnt work anymore.
I wonder why these items have so many 5 star reviews.
Yesterday after putting some food in the oven in the morning i had some time while waiting for it.
After disassembly, it looks like this:

The button is a standard SMD button, i had some equivalent replacement.

After exchanging it, it works again. Lets see for how long …

Almost forgot, the failed button after gentle disassembly:

Filed under: Electronics,Off Topic — Michael @ 22:14

July 7, 2018

Copyright EU #3

The EU Parliament has rejected to fast track, (that is to pass it a few days ago) the controversial directive. IIUC it can now be modified by politicians and will be voted on again in September. Parliament debate and vote from 5th july 2018 (note this has subtitles if you do not understand the MEP who speaks in his native language).
If you care about this, you probably want to stay active and keep an eye on how this unfolds.
Also for those not seeing the problem, think about just sites like wikipedia and how exactly upload filtering (that costs money) or some link tax would work for them. Or how free software projects like FFmpeg could run a bug tracker where people upload small samples of media files which trigger bugs. Of course who and what this directive might affect depends on the very fine details how it is worded and also how the actual implementations in law in each European country will be worded.

Filed under: Off Topic — Michael @ 11:04

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