Joe Mike Terranella published a video tutorial on how to change your direct feed extruder system into a Bowden 3D printer. He used his Hictop Prusa clone to change it from direct feed to a Bowden setup but you can see many useful tips that can be used for other machines also.
Here is the full tutorial video:
Full parts list is on the video description but he used this Bowden conversion thing:
For those demanding high-volume jobs on big objects LulzBot has released their MOARstruder extruder. It is priced at 395 USD.
From produce description:
Bigger. Faster. Stronger. MOAR: The LulzBot TAZ MOARstruder Tool Head is a high output tool head with an extra-long heater block, dual print cooling fans, and a 1.2 mm diameter nozzle. These features enable high-speed printing and tough 3D printed objects.
Orbital Composites is a company which developed advanced carbon fiber and wire 3d printing with applications in space additive manufacturing. It should enable future missions to 3d print satellites and objects in orbit or to 3d print drones with carbon fiber structures.
Here is the interview with Orbital Composites Founder and CEO Cole Nielsen and presentation of their tech:
Direct and Bowden extruders both have their limitations and advantages. Flying extruder for Delta 3d printers should have the best of both types. Flying extruder should have few key advantages:
Remove weight from the moving portion of the printer, making momentum shifts much easier
Remain “close” to the hot end to enable effective printing of flexible materials and remove tube friction
Reduce motion “lag” caused by lengthy tube traversals
The extruder is suspended by rubber bands. These are running around several rolls to increase the length (each around 2m relaxed) to have more or less the same force over the whole vertical range. The extruder is connected with a very short latex tube (around 75mm) to the nozzle. This tube decouples the high frequencies between the nozzle and the extruder. Long story short: I'm printing with no problems with 75m/s and 3mm retraction and still with the same acceleration of 800mm/s². But this was only a short test and I think I can bring it up with a bit optimization. Another advantage is, that it's now easier to build an enclosure and that the printer is much quieter, because the extruder is decoupled.
Here is a video of flying extruder in action. The developer claims that the strange motion is due to Kisslicer and that prints are very good.
Here is an Instructable on how to build a DIY chocolate extruder for Ultimaker original. It is based on 20ml syringe with the inner diameter of 20mm. Syringe is covered with aluminum foil, then Kapton tape. The heater is made of NiCr wire coiled on covered syringe and itself covered with Kapton. To get uniform temperature on the syringe a layer is added of aluminum foil and Kapton outside the heater. Thermistor is NTC 100kOhm .
Martijn Vaeder devloped a novel cold end extruder which drives the filament with belt drive. Here is what he says abut his invention:
The idea for this new type of cold end came to me through having a lot of frustrating experiences with the Greg Wade's cold end, such as frequent slipping of the filament, the drive wheel grinding into the filament, the deformation of the filament which causes extra friction in the PTFE tubing and overall lack of force to extrude the filament. I thought "why couldn't you exert force on the filament from both sides of the filament by adding gears between the drive wheel and the flywheel?".
Early prototypes showed me that this improved the extrusion performance significantly. Unfortunately it still deformed the filament the same way as the Greg Wades cold end. Therefor I thought: "what if you increase the contact area between the filament and the drivewheels, so you can reduce the force pressing down on the filament while increasing the extrusion force?". This brought me to using a belt and wheel to clamp the filament between, which gave very promising results during early prototyping. Now many iterations down the line I present to you the Vaeder curved and geared cold end.
Features and technical specifications from product page:
Excellent performance with flexible materials
Light weight and compact design
Extremely fast and reliable printing with flexible materials such as NinjaFlex and PVA
Small light weight package
100% All-Metal enables reliable and continuous printing up to 315 deg c.
Unlike other extruders (No Teflon tubing or plastic parts inside the hot-end).
Key Features:
Like all Micron 3DP extruders & hot-ends, the Cobra extruder line comes with the patent pending easily replaceable nozzle and guide.
It takes less than a minute to switch to a different nozzle size or to a different material, without changing the calibration of the Z height.
Reliable design: Cobra extruders use a small but powerful 1:13 planetary geared motor equipped with a 304 stainless steel hobbed gear. Including a special tooth profile which provides strong filament gripping.
Continuous idler bearing with preload adjustment, using 2 set screws
Easy opening service door that maintains idler bearing preload while opening and closing.
Short and Smooth filament feeding design that prevents the filament from jamming after passing the hobbed gear.
Test proven with PLA, ABS, polycarbonate, nylon, Carbon PLA, HPIS, Ninjaflex and PVA.
High flow rate package available, sold separately.
Electrical Specification:
Step motor rated current/Phase: 0.67 Amp. Rated voltage/Phases: 6.2 VDC
D-Coil is a new digital 3D modeling approach using wax coiling to bring tangibility to the design of digital models. After defining a shape to extrude, the users follow the lead of a hand-held actuated extruder to instantiate the actual extrusion using wax. The tangibility of the wax extrusion sets the stage to create the next components until the digital model is completed.
The digital model affords all digital attributes (ease of transformation, distribution, and 3D printing) while the wax artifact can be discarded or kept as a one-of-a-kind memento.
We present a proof-of-concept implementation of D-Coil and showcase how this additive approach can also be extended to a subtractive process using a digitally actuated cutter. By adding a 6DOF mouse, users can also include scaling, rotation, and bending effects to create a wide variety of shapes often difficult for novices to produce in standard CAD software.
Here is an interesting dual extruder type where both extruders are powered only with one stepper motor. This setup makes the extruder much lighter and should improve any oozing issues.
The other problem with dual extruder is when one hotend is working, the second would cause ooze. Ooze will make printing model caught a lot of unwanted results. My solution is letting the second hotend to dock on a metal plate to block hot plastic drops from nozzle. To do that first the second nozzle need to swing and raise above metal plate. At the same time one filament need to be caught in between idler and extrusion gear teeth with enough pressure.
All the files and instructions to make Sega can be found at:
E3D is well known for their high quality hotends like E3D v6 and now they present new and low cost affordable alternative: the Lite6. It costs only 21,50 UK pounds and gives unbeatable cost/performance ratio.
Diamond hotend is a new attempt to make a hot end capable of mixing three colors from three filament inputs.
Key features from product page:
3 pcs inputs for 1.7 mm filament
Common 0.4 mm nozzle orifice
Smallest possible mixing chamber for minimal waste and fast color change
Cutout for standard 40W heater cartridge and leaded thermistor
3 pcs threaded mounting holes for state of the art E3D v6 HeatBreaks & HeatSinks
Combined mounting bracket and airguide for optimal cooling by a simgle fan
Optional pendant for attaching a 5015 blower fan for extrudate cooling
The key feature of The Diamond Hotend is the diamond shaped nozzle. We have designed the nozzle to have smallest possible mixing chamber, to make color shifts as fast as possible and to avoid unnecessary filament waste. To ensure rapid nozzle heat up we have constructed the nozzle as compact as possible.
Here is the KS campaign video:
Here is Diamond hot end printing in multiple colors on Prusa I3:
Standard extruders are heated by simple resistive heaters and you basically need to push enough 12 or 24 V DC electric current trough a resistor and simple MOSFET.
Induction heated extruders would have many advantages over them: faster heating up, no high temperature insulation is needed and less thermal mass. All of this could make induction heaters light and fast. Main disadvantage is the more complex electric circuits needed to power it and more complex control unit since it is using much higher voltage and hundreds of kHz AC.
Slow convergence to desired steady state temperature at extruder tip, (many seconds, up to several minutes) and
slow feedback loop for temperature control, (from 100's of ms to s)
Lack of fine-grain temperature control at extruder tip, in steady state, the entire metal nozzle is essentially soaked to, or near, the melting temperature.
Inconsistent feeder response due to varying liquid plastic volume near tip and
limits on filament and extruded plastic drop size
The extruder tip with inductive heating coil would be physically similar in appearance, but would have several distinct differences:
Rather than a metal nozzle, it would be made of a thermally insulating, nonconductive material such as glass or boron nitride.
The actual heated element would be buried inside the tip to make direct contact with the plastic
The power for heating is transferred through electromagnetic coupling of a driving coil to the heated element. The heated element, (and the molten plastic around it), are thermally isolated from the rest of the extruder.
By using inductive heating and passive, digital temperature sensing of the heating target at the nozzle tip, significant improvements can be made to the issues above, resulting in faster production of more isotropic/mechanically stronger plastic prototypes. Also, the above problems typically put a limit on useable filament size, something this system should be able to surpass.
Here is the comparison of resistive heated extruder vs. induction heated extruder:
Resistive compared to inductive heated extruder head, schematics made by aka47
RepRap builder SB made a post about his induction heated extruder, here is his work and schematics:
Induction heated extruder, you can clearly see the induction coils
The induction coil heats the sleeve made from mild steel (ferromagnetic) while the stainless steel is not heated directly because it is not ferromagnetic.
There are other people actively experimenting with this concept like Bulent, who made the extruder and posted a YT video of it working (his videos are not in English, but you will get some insight):
Here is a video showing more details, but again language is not English:
As someone noticed in the comments, it would be interesting to see the induction extuder based on filament with metal particles where induction heats the filament itself. Then you could reduce the mass even further.
Another thing to mention is a possibility that the induction coil will interfere with nearby electronics and maybe emit noisy radio waves. It could also interact with build platform or other parts causing heating or melting damage.
If you want to build a serious desktop induction heater for metal melting of larger pieces here is a link:
Italian 3d printer company WASP presented a novel extruder for big machines that will 3d print houses in the future. Their clay extruder has a sieve and mixing auger and rotates as it deposits building material that can be sourced locally in poor countries.
Here is the project description:
Massimo Moretti and his collaborators don’t forget their main focus: to build 3D printed houses with a very low cost, expecially in developing counties. Now here we are to the turning point: WASP exhibit for the first time at 3D Print Hub in Milan the new extruder, completely redesigned, a rotating extruder.
It is a small revolution. Advantages are several. This kind of system require little energy, it cleans by itself, it can be assembled and disassembled in a very few time, it has a costant speed control. These technical solutions can be transposed in a bigger scale. This is the reason because WASP team consider this transition as crucial in 12 meters tall 3D print building, which is in progress. WASP will give very soon more details about this new fronteer, which has been reached thanks to the constant research.
Here are the videos of extruder and Wasp large clay delta making house parts:
Here is a video of the extruder printing with long straw fibers to give more strength:
ExtrusionBot has new flagship filament extruder model: the EB2. It features high extrusion speeds at 6,5 feet per minute and modules that can be attached to it like cruncher that will shred 3d printed objects for recycling into new filament and spool winder.
Technical specifications:
automated touchscreen user interface
expanded materials (Nylon, HDPE, LDPE, HIPS, PET, plus ABS and PLA)
filament cooling mechanism
universal power adapter
embedded pellet hopper
2 USB ports for smart module attachment
Price: 899 USD
Spooler module will ensure that the extruded filament is properly coiled up
Cruncher module will crunch your failed or unwanted 3d printed objects and make new filament from them
Scot A. Brown published a post on 3d printed rotational extruder "Rotruder" that produces continuous stream of clay objects. The rotating parts of the extruder form a mold when they are closing together. Interesting concept and example of mold+extruder being made by with 3d printed parts. I think it could be used with other pasty materials or even food. I have not found any design or technical documentation.It would be interesting to see the mechanism of power transmission that turns the six mold wheels.
DIY syringe pumps and other syringe devices are used in different 3d printing projects for depositing various materials from living cells to solder paste dispensers. Liam Gilbertson posted a very detailed tutorial on how to build your own syringe extrude from MendelMax 2.0 or any other 3D printer based on 2020 extrusion rails. Be aware that this is not a novice level project since the extruder is very sturdy and may require some machining knowledge and more specialized tools like laser or water jet cutter able to cut 3mm aluminum.
Step-by-step build guide, all the files and code can be found here:
Flex3Drive is innovative extruder system made by Mutley3D from Uk and developed by the CEO Jason Perkes.
Flex3rive print results
Flex3Drive schematics showing the flexible drive shaft and motor
Flex3Drive is a complete end to end, flexible driveshaft based extruder system offering several key advantages over other systems, including:
a lighter X carriage
faster print and travel speeds
reduced retraction distances
increased retract speeds
The extruder motor is mounted remotely from the extruder itself and attached to the frame or x ends of a printer allowing the extruder to move faster with less vibrations. Flex3DriveTM is also fully compatible with Delta type machines.
Technical specifications:
Weight: 45 grams without hot end
Envelope: 50 x 45 x 45mm x y z
Gear Ratio: 40:1
Gear Type: Nylon IM (QDrive) Worm Wheel gear set
Hobb diameter: 11 x 8,5mm
Filament siameter: 3mm or 1,75 no extruder change required
Tested Filaments: ABS, PLA, Nylon (various), Laywood, NinjaFlex, Laybrick, Acetal - tglasse and more ...
ImproTable 1000 is a big custom made DIY 3d printer developed by James Chang. It has 1m x 1m printing surface and unique mixing extruder with five filament input ports. It mixes the color of filaments and looks like it is working fine and fast. There are no details or design plans of this machine released.
Here is ImproTable 1000 (great name btw ...) in action:
Here is a focus on the quint-extruder:
On James YouTube channel there is also a video of Twin 3d printer that has two separate independent dual extruders:
Hopefully we will find out more about James Chang and his machines in the future ...
Five filament types of different colors go in the nozzle, what would happen when different filament materials would be mixed?
