Anyone who has worked with a 3D printer understands the struggle of dealing with watching a print suddenly and without warning fail right before your eyes. Be it a slightly out of alignment axis, incorrect printing temperature, flawed g code or the looming and inevitable filament jam in the hot end, it is never fun watching hours of work explode into a mess of wasted filament. Not only is your time valuable, but let’s be real, 3D printing filament is not cheap.
One of the more frustrating printing failures is when your printer’s hot end causes a filament jam, ending the print job and potentially damaging your printer. Oftentimes jams of this nature require the extruder to be completely removed and the plastic literally chipped out of the nozzle by hand. Sometimes the hot end will even need to be soaked in acetate to dissolve the plastic in order to work correctly again. That is not an especially fun situation to find yourself in; not only is it messy and time consuming, but if you’re not careful you could end up needing an entire new extruding mechanism.
The nightmare of dealing with jammed hot ends is what inspired maker Ho Leong Khit to create his OPAM (One Piece All Metal) water-cooled hot end. It was designed to print with temperatures as high as 350°C and yet be cool enough to the touch to allow you to actually hold it while it is extruding plastic. He has launched his new hot end on Indiegogo and is seeking a relatively modest $9,000 to produce the OPAM. Early birds have the option of getting one for only $60, while the retail price will be about $70.
The OPAM will be able to print using ABS, PLA, PC-ABS, and virtually any high temperature 1.75mm filament. The nozzle, heater block, and the heat sink have all been combined into a single piece, thus reducing the possibility of jams. The single construction has a 4mm transition from cold to hot portion making the extruder weigh only 40 grams, which can dramatically speed up printing speed and accuracy.
Take a look at Khit’s crowdfunding video here:
Khit spent over six months prototyping and testing the OPAM, going through a half dozen different prototypes and variations. Each of the prototypes was tested with well over 50 hours of printing time using both ABS and PLA filaments. His final prototype has printed multiple single object prints lasting over five hours with no jamming issues of any kind.
“I ran multiple thermal simulations to get the best estimation of the temperature within the hot end and verified the results by testing the actual prototype. While it allowed me to print without any jams, I felt that the design could be further improved to handle extrusion temperatures above 300°C,” Khit explained on Indiegogo.
Beyond the one-piece construction, the key to Khit’s simplified design is the water-cooling system that is considerably more effective and consistent than air cooling. He also removed any PEEK or PTFE material, which prevents leaks and jams and doesn’t allow galling of the nozzle because it is built in and has no threads to wear down. The hot end will be open sourced, and as soon as his funding goal has been reached and the first units shipped Khit intends to release the specifics and technical drawings.
Khit is looking to raise enough funds to produce the OPAM cheaply enough to be affordable for almost any 3D printing budget. When you back his campaign for $60 or $70, you’ll receive a single OPAM hot end, a 12 volt submersible water pump for the cooling system, 16 feet of hydraulic tubing, and a 3D printed height extension. Shipping is $10 worldwide (unless you’re in Singapore, where it will be shipped for free).
You can check out all of the specific details about the OPAM over on the Indiegogo campaign page, and let us know what you think. Is the OPAM worth $70, or are there other options on the market that are better? Let us know on the One-Piece All-Metal Water-Cooled Hot End forum thread at 3DPB.com.