Texas-based re:3D is accepting pre-orders for Gigabot's new generation of large-format FDM 3D printers and specialized extruders for printing granular plastics.
The small but successful Austin-based manufacturer is entering Kickstarter for the third time, having launched crowdfunding campaigns for the Gigabot 3D printer in 2013, and then Open Gigabot in 2015. As the name of the line suggests, the company specializes in large-format 3D printers.
The new Gigabot X device was no exception - essentially a variant of the flagship Gigabot 3+, but with a new extruder. Currently, the company produces three versions of the third generation 3D printer, differing in the size of the construction area - 590x600x600 mm (Gigabot 3+), 590x760x600 mm (Gigabot 3+ XL) and 590x760x900 mm (Gigabot 3+ XLT).
re:3D engineers initially focused on creating systems for 3D printing with plastic waste, and not only for reasons of environmental friendliness, but also cost savings. Developers are gradually moving towards the goal, and the next stage is the transition to printing with granulate, because the cost of filament in comparison with granulated plastic of the same mass easily increases by an order of magnitude. In addition, granular plastic is available in a wider variety than pre-made filaments.
When it comes to desktop 3D printers, we can see that the prices of these devices have dropped significantly over the past few years. Now almost everyone can afford to purchase such a device and make it a part of their life, creating a wide variety of three-dimensional products. There is only one obstacle that causes refusal to purchase a 3D printer - the cost of the material. Now experts have overcome this problem and have designed a device that allows you to create working material right at home, and its price, compared to the standard one, looks simply ridiculous.
Average price for plastic thread is about 40 dollars per kilogram. Those people who actively use 3D printers know very well that such a quantity can be used within just a couple of days. If you do some simple math and multiply this cost by weeks, months or years, you can end up with a pretty tidy sum.
Recently, companies have become concerned about this issue and have begun to create special devices that can reduce the price of thread from tens of dollars to just a few. These machines create working material by melting down special plastic granules, followed by winding the finished thread onto a spool. It is much easier to obtain granules, and accordingly this helps to reduce the final cost of operating 3D printers.
Very soon, 3devo will present to the world its product, previously registered on Kickstarter. NEXT 1.0 is one of those machines that will allow you to create filaments for FFF/FDM printers right at home.
“FFF/FDM material creation machines come from a variety of companies, but what sets 3devo apart is their attention to detail and the quality of the final product, as well as the material that will be produced in the process. Unlike other similar devices that create low-quality thread with a loose structure, NEXT 1.0 is designed for the production of professional material. This filament can subsequently be easily wound directly onto the spool of 3D printers, which allows you to achieve truly incredible results. 3devo does everything possible and impossible to make your life truly comfortable,” says Lucas van Leeuwen.
NEXT 1.0 has 7 main functions, which, according to company experts, distinguish it from other similar devices:
- Creating high quality thread - special system sequential extrusion makes it easy to transport granules inside the device and turn them into dense threads.
- 3D Heating System - Unlike other home FDM/FFF filament machines, NEXT 1.0 features three heating zones, and the temperature of each can be adjusted independently.
- Built-in Hopper sensor - it will remind the user that the pellets are running low and it’s time to take care of refilling.
- Diameter control system – the user independently selects the diameter of the thread being produced.
- Automatic winding system for finished thread.
- Possibility of easy and quick replacement coils.
- An accessible and intuitive user interface that can be used even by people using the device for the first time.
The creation of machines for generating FDM filament is not only providing users with the opportunity to save money, but also the next step in the development of 3D technologies. In the future, 3devo wants to add the ability
One of latest developments devices for 3D printing was the emergence of extruders. No, we are not talking about the print heads of FDM printers, although these are also extruders, but about portable desktop devices for home production of plastic rods.
What exactly is an extruder? This is a device for forming products by melting or liquefying consumable material and squeezing the mass through an opening a certain shape. In fact, a regular meat grinder is a kind of extruder.
It is precisely these “meat grinders” that are used for industrial production rod for 3D printing. Moreover, the design of such devices is extremely simple: plastic granules are poured into a hopper and moved inside a heated tube, or “sleeve,” using a screw (aka “Archimedes’ screw”). By the end of the short journey, the plastic is heated almost to the melting point and is squeezed through the round hole in the “head”, forming a thread. Then the thread is cooled and wound onto a bobbin. It would seem nothing complicated. So why not start making thread at home?
It is quite possible. For what? If only because granules of the same ABS plastic are much cheaper than a finished rod of the same weight. How much? Compare for yourself: one thousand to one and a half rubles for a finished spool with a kilogram of thread or 50-70 rubles per kilogram of plastic granules.
In addition, you will have the opportunity to control the process. You never know who mixes what into consumables to reduce costs? Finally, you will have the opportunity to experiment with various materials, considered “exotic” in the world of 3D printing, but in reality often lying right under your feet. Take, for example, the same PET, from which almost everything is made plastic bottles for drinks. It's free too consumables, and a way to improve the environment.
An extruder can be made from scrap materials, but the growing popularity of such devices has also led to the emergence of commercial models. Today we will take a look at the most well-known solutions, and we will later publish the details of building an extruder with our own hands on our Wiki.
Filabot
The most famous brand on the market, represented by a line of extruders and a plastic crusher. More on the crusher later.
The company's first model was the Filabot Original extruder - a rather nice device the size of system unit computer. According to the developers, the device is capable of producing thread from ABS, PLA and HIPS, and even with the possibility of adding carbon fiber. In addition, it is possible to add dyes. The productivity of the device is high, reaching 1 kg of plastic in five hours of operation or about 45 meters of rod per hour. In other words, this machine can produce stock faster than the average FDM printer can use it up.
And here one small problem arises, although not critical: at such an extrusion speed, it would be nice to equip the device with a fan to cool the plastic at the outlet, otherwise the thread may stretch under its own weight or stick together. Unfortunately, the developers did not bother with this problem, apparently believing that extrusion will be carried out from the table to the floor, with sufficient time for cooling before winding...
A more serious problem is the cost of the extruder - neither more nor less than $900. In a fun attempt to reduce the cost of the device, the company decided to stick to its marketing strategy and suggested Filabot Wee. This model is not much different from the original, except for the wooden case, but it costs $750. Finally, there is the option to purchase Filabot Wee as a kit for $650.
Filastruder
Filastruder was developed by a couple of filament obsessives ( see video) by student craftsmen named Tim Elmore and Allen Haynes from the University of Florida in a closed project, then successfully tested among equally obsessed 3D makers and finally offered on Kickstarter in the already finished form as a cheap alternative to Filabot extruders. The device costs only $300.
The performance of Filastruder in comparison with Filabot is inversely proportional to the price, reaching about 1 kg of plastic in 12 hours of operation. But as we have already noted, the pace of Filabot’s work is simply excessive for home printing. For the needs of a single enthusiast, the performance of the Filastruder is quite enough, and the more modest price tag will be a definite advantage. Filabot is better suited for use by groups of makers, or as a source of income. Why not? Four to five kilograms of thread a day can turn into a good amount if there are buyers.
Lyman extruder
Where, in fact, it all began. A modest 83-year-old retiree from Washington state (which, by the way, is on the opposite coast from the US capital) decided to show young people what’s what. And yet he succeeded! Armed with a jigsaw, drill, screwdriver and talent, Mr. Hugh Lyman built a rod extrusion device. Well, okay: maybe he wasn’t the instigator, because the idea was in the air quite for a long time, but it was Hugh who developed a simple, suitable installation and posted the drawings in open access, which already makes him a hero among 3D makers.
By the way, this no longer a young man has a quite interesting, albeit little-known list of merits. For example, in the 70s, he headed the Ly Line company, which tried to promote portable computers to the market about eight years before the appearance of the first mass-produced Mac. True, this “portable” device weighed a modest 25 kg... But was the idea correct? So this time, Hugh Lyman, already retired, did not make a mistake.
As it turns out, Hugh became interested in 3D printing. He does not consider himself a full-fledged engineer - he never defended his diploma, despite his university education. On the other hand, talent trumps bureaucracy. Having dabbled with 3D printers, Hugh came to the conclusion that the technology was nice, but the price tag of $30-40 per kilogram of rod was a bit irritating. After hearing about the Desktop Factory Competition, that is, “a competition for homemade desktop factories,” Lyman decided to shake off the old days.
The condition of the competition was the creation of a generating device from publicly available components with total cost less than $250. Lyman brilliantly failed his first attempt for one simple reason: he did not take into account the cost of the components he made himself, and thereby violated the terms of the competition, exceeding the conditional cost. After quickly refining the design, the second version of the Lyman extruder was born. Result? Unconditional victory. Of course: even taking into account energy costs, the cost of a homemade rod made from granules is several times lower than the cost of a “branded” product. And if you use “scavenger” material... Speaking of garbage:
Filabot Reclaimer
The main limitation of extruders is the use of pellets to produce rods. Neither Filabot, nor Filastruder, nor Lyman's extruder are able to “digest” large pieces of plastic. These are the features and limitations of the design. But the main potential of home extruders is precisely in the processing of plastic waste: bottles, packaging and simply unsuccessful models or 3D printing waste - rafts and supports.
Fortunately, this problem can be solved quite simply: the developers of Filabot already offer a plastic crusher called the Filabot Reclaimer. This device is exceptionally environmentally friendly with a power of one human force. In other words, it is a shredder with manual drive. The device crushes plastic into particles smaller than 5mm, turning plastic waste into easily digestible raw material for extruders. Issue price: $440. Yes, not cheap. But the raw materials are free. The developers point to the possibility of processing ABS, PLA and HIPS.
Overall, the idea of home rod making devices, including recycling plastic waste, is quite new. Of course, the appearance of such devices was to be expected - this is a completely logical development of the concept of home 3D printing. As with any new ideas, the prices for ready-made devices are high, but craftsmen always have the opportunity to build an extruder with my own hands. Fortunately, the drawings of all the listed devices were made publicly available. Of course, extruders are not a panacea. Along with the attractive economic potential, it is worth considering technological subtleties home production. Not all types of plastic can be melted down: for example, PLA is easier to throw away than to recycle. In addition, a homemade rod will produce a fairly large percentage of rejects, and repeated recycling of even suitable plastic inevitably leads to its degradation.
However, using fresh pellets mixed with recycled plastic can result in significant savings in printing costs.
Let's continue on the topic of how the filament is fed into the melting zone (HotEnd).
In the photo, the classic Reprap extruder is the ancestor of all 3D printing mechanisms for homemade people.
It is worth noting the fact that the gearbox (with a ratio of at least 1:5) Necessarily needed to drive filament with a diameter of 3.0 mm. The purpose of the gearbox is to increase the torque on the shaft by reducing the rotation speed. In other words, it will spin stronger, but slower, and we don’t really need a high rotation speed - the plastic should have time to melt.
If we are dealing with a rod of 1.75 mm or an even smaller diameter, then we do not need to make a gearbox. Although, if a very weak motor is used (for example, from an old Epson printer, which I used at first), then the gearbox will still have to be made.
The photo shows just such an engine and an extruder made on its basis from parts from old printers.
In industrial 3D printers, the extruder looks very similar:
The photo shows the heart of a printer from Stratasys - the same comrades who invented (and patented) the technology of printing with molten plastic.
There are, of course, more sophisticated options, but they are rather complicated to implement, and therefore are not suitable for independent (handicraft) production:
Since 3 mm plastic is significantly (!) cheaper than thinner options (and also more common), we will make the drive based on thicker filament. And we can “push” plastic 1.75 (and similar) with this extruder without any problems at all. In this case, only minor modifications to the hotend will be required (more on this later).
So.
First we need an engine. Moreover, it is stepper and very preferably bipolar, otherwise you will have to tinker with the controls. You can distinguish it from unipolar (another type of stepper) by the number of pins. There should be 4 of them. In this case, you can use a standard control driver (Pololu). Diagram of such an engine:The color of the wires can be absolutely any, so we check where the windings are with a tester. Regarding the beginning/end of the winding, we will determine this experimentally when connecting the engine.
In principle, you can also connect a motor that has 6 terminals - the main thing is to correctly determine where the windings are, after which there will simply be 2 unnecessary wires that can simply be cut off.
In this case, we will have the “yellow” and “white” wires left unconnected.
You can extract a lot of useful things from old printers, but the engines there are very weak, especially in new inkjet printers, so they are only suitable for use with gearboxes with a very large gear ratio. Here is an example of such engines:
Of all this variety, only the Epson EM-257 is suitable for use as a filament drive - it just has the required number of pins (4), as well as more or less good torque on the shaft. Here are a few more similar engines:
They are of course rather weak for our purpose, and, ideally, it is better to use an analogue of Nema17 (the one used in the original rap), but they can be bought for pennies on any radio market or picked out from old hardware. By the way, you should not take the Soviet DSHI-200, which are very popular among machine tool builders, as the basis for the extruder, because they are too heavy to be pulled around as a print head.
Among those available in Russia, one can highlight the website of the Elektroprivod store, which sells an analogue of Nema17 - FL42STH. I chose FL42STH47-1684A motors for the printer, which are perfect not only for the extruder, but also for driving all axes.
Now we need a gearbox.
It is clear that the smaller its dimensions, the better for us - the total mass of the print head will be less, and accordingly the positioning speed (as well as the printing speed in general) will be higher.
It was originally planned to use stepper motor with planetary gearbox industrial production, like this:
But finding it in Russia at a normal price is simply unrealistic, and in China they are sold at very low prices. available means, therefore, as always, everything is done on our own.
For myself I determined (eventually) perfect option - planetary reductor, pulled out of an old screwdriver, converted to use with a stepper motor.
The donor looks something like this in the photo. And in disassembled form something like:
The photo is not mine, but fundamentally these planetary gearboxes are not very different from each other. Therefore, we are looking for a dead screwdriver and go ahead and disassemble it.
As before, we will need a smart turner who will help us fit the drive gear from the original screwdriver motor onto our stepper. It will also be necessary to machine the housing cover for the output shaft bearing. I'll post photos of my version later (I'll have to disassemble the finished extruder). It is possible, in principle, to make a drawing of a cover that has been machined from aluminum, although the turner usually suffices with a simple explanation “on the fingers” of what exactly we want to get from him.
It seems like it’s time to pick up the camera and start a detailed photo shoot of all the intricacies of the process, otherwise the Internet has run out of pictures that would ideally suit my description.
How to assemble a Mosaic printer from a set of parts from MakerGear is described in the article Assembling a 3D printer with your own hands. You probably noticed that the structure of a 3D printer is discussed in detail there, but not we're talking about about the print head. This is the topic of today's conversation.
We will look at the types of extruders and manufacturing methods individual parts this complex mechanism in order to understand how to make an extruder with your own hands (video about drilling a nozzle at the end of the article).
The print head of a 3-D printer pulls a rod of plastic, heats it up and pushes the hot mass through the nozzles.
Wade extruder
The picture shows a simplified diagram of a Wade type extruder. The device consists of two parts. At the top there is a cold-end (cold end) - a mechanism that feeds plastic, at the bottom - a hot-end (hot end), where the material is heated and squeezed out through the nozzle.
Bowden extruder
There is another design of the device, where the cold and hot parts are separated, and the plastic enters the hot-end through a Teflon tube. This model, where the cold end is rigidly fixed to the printer frame, is called Bowden extruder.
Its undoubted advantages include the following:
- the material does not melt prematurely and does not clog the mechanism;
- The print head is significantly lighter, which allows for increased printing speed.
However, there are also disadvantages. A thread of plastic on this long distance may become twisted and even tangled. The solution to this problem can be to increase the power of the cold engine.
Cold end
E3D-v6 assembled
The filament rod is pushed down by a gear driven by an electric motor with a gearbox. The feed wheel is rigidly mounted on the motor shaft, while the pressure roller is not fixedly fixed, but is in a floating position and, thanks to a spring, can move. This design allows the plastic threads not to get stuck if the diameter of the rod in certain areas deviates from the specified size.
Hot-end
Plastic comes into bottom part extruder through a metal tube. This is where the material is heated and flows out in liquid form through the nozzle. The heater is a spiral of nichrome wire, or a plate and one or two resistors, the temperature is controlled by a sensor. The upper part of the mechanism should prevent the filament from heating up early and not allow heat to escape upward. Heat-resistant plastic or a radiator is used as insulation.
Feeder
First of all, you need to choose a stepper motor. It is best to buy an analogue of Nema17, but motors from old printers or scanners, which are sold very cheaply on radio markets, are also quite suitable. For our purpose, we need a bipolar motor with 4 terminals. Actually, you can also use unipolar, its diagram is shown in the figure. In this case, the yellow and white wires will simply remain unused and can be cut off.
As a rule, printer motors are weak, but the EM-257 (Epson), as in the figure below, with a shaft torque of 3.2 kg/cm, is quite suitable if you are going to use Ø 1.75 mm filament.
For a rod Ø 3 mm, or with a weaker engine, you will also need a gearbox. It can also be selected from disassembled old tools, for example, a planetary gearbox from a screwdriver.
The modification will be needed to fit the screwdriver motor gear onto the stepper and align the motor’s rotation axis with the gearbox. And the cover for the output shaft bearing also needs to be made. A gear is installed on the output axis, which will feed the plastic rod into the heating zone.
The extruder housing serves to mount the motor, pressure roller and hotend. One of the options is shown in the figure, where the red filament rod is clearly visible through the transparent wall.
The body can be made from different materials, having come up with own design, or, taking as an example ready set, order printing on a 3-D printer.
The main thing is that the pressure roller is adjusted by a spring, since the thickness of the rod is not always ideal. The adhesion of the material to the feeding mechanism should not be too strong to avoid pieces of plastic breaking off, but sufficient to push the filament into the hot-end.
It should be noted that when printing with nylon it is better to use a feed gear with sharp teeth, otherwise it simply will not be able to hook the bar and will slip.
All metal hotend
Hotends from E3D are widespread and popular. You can buy it on ebay.com for $92 (without delivery) or download the drawings that are freely available on the company’s official website (http://e3d-online.com/), according to which you can do it, saving a lot.
The heatsink is made of aluminum and serves to remove heat from the hotend barrel and prevent premature heating of the print material. An LED radiator is quite suitable; to enhance the cooling effect, you can also direct a small fan to it.
Hotend barrel – hollow metal tube connecting the radiator and a heating element. Made from of stainless steel due to its low thermal conductivity.
This is what the part looks like in cross-section and with dimensions for a rod Ø 1.75 mm.
The thin part of the tube serves as a thermal barrier and prevents heat from spreading into top part extruder. It is important that the filament does not begin to melt prematurely, because in this case the rod will have to push too much viscous mass. As a result, the friction force increases and the tube and nozzle become clogged.
If you drilled the part yourself, you will need to polish the barrel hole. Fine sanding is suitable for rough sanding. sandpaper“zero”, secured with tape to a drill of a smaller diameter.
Finish polishing is required mirror shine(thread and GOI paste No. 1), then it is useful to fry the hole sunflower oil to reduce friction force. To prevent the plastic from heating up too early, you can coat the bottom of the tube located in the radiator with a thin layer of thermal paste.
Another one possible problem: Molten plastic under the pressure of the incoming rod may seep up and cool in the cooling zone, causing the barrel to clog and stop printing. You can combat this with the help of a Teflon insulating tube, which is inserted into the hotend barrel before the filament begins to heat up.
Heater
Heater plate
An aluminum plate is used as a heating element. If you are unable to find a thick block of suitable size, a 4 mm thick aluminum strip, which can be purchased at building materials stores, is quite suitable. In this case, the heating element will consist of two parts. It is necessary to drill a central hole for the hotend barrel, tighten it with a bolt, and clamp the entire structure in a vice. Then drill the required number of holes for the component elements of the heater:
- fastening bolt,
- two resistors,
- thermistor.
To heat the plate, you can use a 12v ceramic heater or a 5 Ohm resistor. But for our block, two 10 ohm resistors are better suited, since they are much smaller in size, and a parallel connection will give the required resistance of 5–6 ohms.
The temperature will be controlled by a 100 kOhm NTS thermistor brand B57560G104F, with a maximum operating temperature of 300 °C. Thermistors with lower resistance cannot be used; they, as a rule, have large error at high temperatures.
It is necessary to ensure a tight connection of the resistors to the plate, since air gap slows down heating. It is important to choose the right sealant here. It is best to use ceramic-polymer pastes (CPDT), working temperature which are not less than 250 °C. For additional thermal insulation, it’s a good idea to wrap the entire hot-end with fiberglass.
Nozzle
A blind nut with a rounded end is ideal for making a nozzle. It is better to take a part made of copper or brass, since these metals are relatively easy to process. You need to secure the bolt in a vice, screw the nut onto it and drill a hole of the required diameter in the center of the rounding.
This can be done this way: on a drill clamped in a regular drill, secure collet with a drill of the required diameter. It turns out to be an interesting design.
A hole of 0.4 mm is considered the most successful, since with a smaller diameter the speed slows down, and with a larger diameter the print quality suffers.
Here is another way to drill a nozzle (video in English).
As you can see, making an extruder for a 3-D printer with your own hands is quite difficult. But if you know that you won’t be able to make some part yourself due to lack of necessary materials or tools, it is not necessary to purchase a complete ready-made kit; you can buy any part of the extruder separately and continue working.
Have fun typing.