The fumes needed to be extracted from as close to the extruder nozzle as possible (as this is the main source of the fumes). To do this, I designed a a special fume extractor nozzle which would get as close to the extruder nozzle as possible without interfering with a print.
The Nozzle
1″ flexible duct hose is sealed into the bottom of the nozzle with hot glue [not pictured above].
Nozzle Close-up
The print came out quite well for one of my early prints. It did not warp at all even though it is quite thick. This may have something to do with the fact it was printed on fresh polyimide film.
Nozzle mounted to the extruder
Above, the nozzle fits right into the black accessory mount, which was printed on a commercial 3D printer. This mount was designed for future add-ons, like an 80mm muffin fan or, in this case a fume extractor nozzle.
Next up was printing the 3″ duct hose exhaust adapters.
Exhaust Adapters
These adapters just press fit onto the exhaust end of the blower fans. The 3″ duct which leads to the out of the house is secured to the adapter with a duct clamp.
All four adapters mounted on the blower fan
The images above and below show the adapters mounted onto the blower fan.
Angled view: All four adapters mounted on the blower fan
Just to clarify, the events of the majority of these blog posts are from the summer (2010) when I was assembling my machine. I have a lot more posts to catch up on before I really get to the machine as it currently is. I only created this website awhile after I had completed my printer and I felt that sharing its progress from the very beginning would be of interest to the community. So stay tuned for more posts :)
During thermal processing, ABS plastic fumes are not a very good thing to be breathing in. Most ABS plastic MSDS (Material Safety Data Sheet) warn that “Thermal processing fumes may cause irritation to the eyes, skin and respiratory tract and in cases of severe overexposure, nausea and headache”. So, one of the very first things I printed was a fume extractor to send the fumes outside.
Finished print of Suction Adapter
To make this fume extractor, I decided to modify a very old “squirrel cage” type blower fan that I had. So, with the help of my trusty calipers, I created some adapters in Solidworks that would allow 1″ and 3″ diameter hose to connect to the suction and blower ends of the fan.
Suction Adapter
The prints came out pretty nice, but I have improved a lot on the print quality since then. They are rock solid, with a 4mm wall thickness, and the cone is at a 35° taper so support material is not required.
Two Suction Adapters
I printed out two adapters because this blower fan was actually two sided, powered by one motor. The initial idea was one fan would be the fume extractor for my large machine and the other would be the fume extractor for my Fab@Home.
Suction Adapters Mounted on Blower Fan
The AC motor is in the center and the suction adapters attach to the two “squirrel cage” blowers with #4-40 screws. 1″ flexible hose attaches to the smaller end of the suction adapter, sealed with hot glue. This 1″ hose brings fumes from the vicinity of the print head nozzle.
