How to make homemade 3d printer

And then I thought, what if I spray metal in the place I need, gradually increasing the thickness? I looked for information about whether someone did this - I did not find it.

Registered on the forum, where sprayers gather together and began to disturb them with questions like: is it possible to build up a "film" with a thickness of 1 or more millimeters. To which I caught a lot of misunderstanding what it was for, but received a positive answer.

General information received, you can begin to prepare for experiments.

It is known from various articles and documents that a vacuum of no more than 10⁻² Pa is required. For comparison, the order of magnitude - the pressure that gives a household vacuum pump (Value and others) - about 4 Pa ​​(measured value), i.e. pressure is 400 times greater than necessary. How to deal with it and what to do? To achieve low pressures, turbomolecular vacuum pumps are used, they work in parallel with the foreline pump and, literally by molecules, capture the remaining air from the chamber. The process is not fast. The pump looks like this.

We installed a pump, it pumps out air and everything seems to be fine, but how to find out the pressure? For this I chose an ionization vacuum gauge.

In fact, nothing else is needed, except for the chamber and evaporator. I did not find a ready-made affordable (in terms of finances) camera, therefore, I decided to make my own. It is of a small volume (about 8-10 liters) in order for the air to be pumped out faster. Usually, the chambers have a spherical shape, in my case it is, on the contrary, elongated, in order to be able to set the “target” (the place where the metal is deposited) at different distances from the evaporator. In addition, the camera has a lot of flanges for connecting all kinds of inputs/outputs and sensors. I modeled the camera in a well-known CAD program, drew drawings and transferred it to production.

Current leads and conductors I made from a brass bar and a brass rod, bought on the local market. (Juno, who is from St. Petersburg).

In the photo below, a tungsten boat is fixed between two conductors.

The bottom part looks like this. The photo shows the cooling tubes of the current leads. Subsequently, I abandoned them, due to the simplification of the system.

Assembling the camera did not take much effort and complexity. It is much more difficult to achieve vacuum retention in this chamber. To do this, I polished the flanges and all mating surfaces to avoid the slightest leakage through the rubber seal (in the photo below, I processed only the top flange).

As it turned out later, the weld is not airtight at all (meaning for low vacuum). I, out of inexperience, assumed that by pumping a pressure of 300 kPa into the chamber and immersing it in a bath of water, I would carefully find all the leaks and eliminate them. Yes, at the first stage I did just that, but the pressure in the chamber did not fall below 10-2 Pa, there were leaks. Interestingly, before the start of the test, at a pressure in the chamber of 300 kPa, bubbles emerged from the welds with an intensity of approximately 1 bubble (diameter 2-3 mm) in 30-40 seconds. And those were big losses that I eliminated. But what to do with minimal vacuum losses that cannot be tracked in "kitchen" conditions?

The solution was close. To do this, all you need is a mass spectrometer.

The idea is simple – the investigated chamber or container is connected to the vacuum chamber of the spectrometer. Air is pumped out, on the graph they look for extraneous peaks of any gases. After that, helium is supplied locally, to the places of possible leakage. It is helium, because its penetrating power is higher and the helium peak can be easily tracked on the spectrum. As soon as helium enters the chamber through a micro-hole, it is immediately visible on the spectrum.

I drove twice and looked for leaks twice. Now the chamber with the installed pump is hermetic and it is possible to carry out experiments further, having previously assembled all the components of the system on the rack.

General view of the incredible installation.

Starting up the plant and checking it comes down to maintaining the lowest possible pressure. The foreline pump is started first.

The pressure after the operation of the foreline pump can be seen in the picture below.

After the pressure is established (does not change). You can launch "heavy artillery" - a turbomolecular pump. It reduces the pressure by another 3 orders of magnitude.

The time has come for experiments, what I have been going for so long and what I have been waiting for so long.

First experiment.

Place a small amount of silver into the boat fixed between the conductors. Above the boat I install a steam conduit - a soldered tin cylinder, which, as I thought, should limit the spread of metal through the chamber. Above the steam conduit there is a lid with a hole of 2 mm, behind the lid there is a target on which the metal should condense. It is a pity that there are no photos left, but the vacuum chamber was completely dusty. There was not a single place where there was no applied layer of metal. In the photo below, it’s not a different planet at all, but silver sprayed onto the inner surface of the wall.

Second experiment.

I thought it was because of the large gaps between the boat and the steam line. The solution was born immediately and quickly. I took two boats and combined them so that a shell was obtained. I placed silver inside, and cut a hole with a diameter of 2 mm in the upper half.

And he began to heat up the whole thing. But, I did not take into account the rigidity of the boats and the rigidity of the current leads. The shells parted a little and a gap formed between them, through which steam also flew in all directions.

As a result - spraying in the entire volume of the chamber. In the photo below there is a viewing window, the boat in which was slightly above half, but the window was completely dusty.

Third experiment.

After a little thought and grief, I thought that the container with the evaporated metal should be airtight and with only one outlet, but how and what to make it. From tungsten - very expensive and difficult to process. The way out has been found! Graphite is an excellent material for making a crucible, let's call it that. On the ad site, I found an ad for the sale of graphite bars from the contact whiskers of a trolleybus, cut out a bar with a hole in the center and made a cover for it. In the photo below - just a bar with a hole for the material (without a cover).

And in this photo already in the chamber with the lid installed (the hole in the lid is 1 mm in diameter).

Under the spoiler are a few photos with a short period of time, from which you can see how dusty the viewing window is.

Loss of transparency

It is obvious that in this case, too, there was no success, to my great regret. All three experiments were carried out with a gradual increase in temperature from the state when evaporation does not occur.

A small video in which the information is presented in a slightly different way, in a different form and volume.

Video link

www.youtube.com/watch?v=4yWQOWIG1qw

Unfortunately, it was not possible to get what was intended, but, on the other hand, invaluable experience was gained in the design and manufacture of vacuum equipment. Most of this experience I have shared with you and I would be very grateful if you express your opinion on this issue.

Thank you all and good luck.

How to build a home 3D printer: recommendations from personal experience

3D printing and assembly of 3D printers is my hobby and passion. Here I will not share detailed diagrams and drawings, there are more than enough of them on specialized resources. The main goal of this material is to tell you where to start, where to dig and how to avoid mistakes in the process of assembling a home 3D printer. Perhaps one of the readers will be inspired by applied engineering achievements.

Why do you need a 3D printer? Use cases for

I first came across the idea of ​​3D printing back in the 90s when I was watching the Star Trek series. I remember how impressed I was by the moment when the heroes of the cult series printed the things they needed during their journey right on board their starship. They printed anything: from shoes to tools. I thought it would be great someday to have such a thing too. Then it all seemed something incredible. Outside the window is the gloomy 90s, and the Nokia with a monochrome screen was the pinnacle of progress, accessible only to a select few.

Years passed, everything changed. Around 2010, the first working models of 3D printers began to appear on sale. Yesterday's fantasy has become a reality. However, the cost of such solutions, to put it mildly, discouraged. But the IT industry would not be itself without an inquisitive community, where there is an active exchange of knowledge and experience and who just let them dig into the brains and giblets of new hardware and software. So, drawings and diagrams of printers began to surface more and more often on the Web. Today, the most informative and voluminous resource on the topic of assembling 3D printers is RepRap - this is a huge knowledge base that contains detailed guides for creating a wide variety of models of these machines.

I built my first printer about five years ago. My personal motivation to build my own device is quite prosaic and based on several factors. First, there was an opportunity to try to realize the old dream of having your own device, inspired by a fantasy series. The second factor is that sometimes it was necessary to repair some household items (for example, a baby carriage, car elements, household appliances and other small things), but the necessary parts could not be found. Well, the third aspect of the application is "near-working". On the printer, I make cases for various IoT devices that I assemble at home.

Agree, it is better to place your device based on Raspberry Pi or Arduino in an aesthetically pleasing "body", which is not a shame to put in an apartment or take to the office, than to organize components, for example, in a plastic bowl for food. And yes, you can print parts to build other printers :)

There are a lot of scenarios for using 3D printers. I think everyone can find something of their own.

A complex part in terms of drawing that I printed on my printer. Yes, it's just a figurine, but it has many small elements

Ready solution vs custom assembly

When a technology has been tested, its value in the market drops markedly. The same thing happened in the world of 3D printers. If earlier a ready-made solution cost simply sky-high money, then today acquiring such a machine is more humane for the wallet, but nevertheless not the most affordable for an enthusiast. There are a number of solutions already assembled and ready for home use on the market, their price range ranges from $500-700 (not the best options) to infinity (adequate solutions start from a price tag of about $1000). Yes, there are options for $150, but we, for understandable, I hope, reasons, will not dwell on them.

In short, there are three cases to consider a finished assembly:

• when you plan to print not much and rarely;
• when print accuracy is critical;
• you need to print molds for mass production of parts.

There are several obvious advantages of self-assembly. The first and most important is cost. Buying all the necessary components will cost you a maximum of a couple of hundred dollars. In return, you will receive a complete 3D printing solution with the quality of manufactured products acceptable for domestic needs. The second advantage is that by assembling the printer yourself, you will understand the principles of its design and operation. Believe me, this knowledge will be useful to you during the operation of even an expensive ready-made solution - any 3D printer needs to be serviced regularly, and it can be difficult to do this without understanding the basics.

The main disadvantage of assembly is the need for a large amount of time. I spent about 150 hours on my first build.

What you need to build your own printer

The most important thing here is the presence of desire. As for any special skills, then, by and large, in order to assemble your first printer, the ability to solder or write code is not critical. Of course, understanding the basics of radio electronics and basic skills in the field of mechanics (that is, "straight hands") will greatly simplify the task and reduce the amount of time that needs to be spent on assembly.

Also, to start we need a mandatory set of parts:

• Extruder is the element that is directly responsible for printing, the print head. There are many options on the market, but for a budget build, I recommend the MK8. Of the minuses: it will not be possible to print with plastics that require high temperatures, there is noticeable overheating during intensive work, which can damage the element. If the budget allows, then you can look at MK10 - all the minuses are taken into account there.
• Processor board. The well-known Arduino Mega is well suited. I didn't notice any downsides to this solution, but you can spend a couple of dollars more and get something more powerful, with a reserve for the future.
• Control board. I'm using RAMPS 1.4 which works great with the Arduino Mega. A more expensive but more reliable board is Shield, which already combines a processor board and a control board. In modern realities, I recommend paying attention to it. In addition to it, you need to purchase at least 5 microstep stepper motor controllers, for example - A4988. And it's better to have a couple of these in stock for replacement.
• Heated table. This is the part where the printed element will be located. Heating is necessary due to the fact that most plastics will not adhere to a cold surface. For example, for printing with PLA plastic, the required surface temperature of the table is 60-80°C, for ABS - 110-130°C, and for polycarbonate it will be even higher
  There are also two options for choosing a table - cheaper and more expensive. Cheaper options are essentially printed circuit boards with preheated wiring. To operate on this type of table, you will need to put borosilicate glass, which will scratch and crack during operation. Therefore, the best solution is an aluminum table.
• Stepper motors. Most models, including the i2 and i3, use NEMA 17 size motors, two for the Z axis and one each for the X and Y axes. Finished extruders usually come with their own stepper motor. It is better to take powerful motors with a current in the motor winding of 1A or more, so that there is enough power to lift the extruder and print without skipping steps at high speed.
• Basic set of plastic fasteners.
• Belt and gears for its drive.

Examples of elements appearance: 1) MK8 extruder; 2) Arduino processor board; 3) RAMPS control board; 4) motor controllers; 5) aluminum heated table; 6) NEMA 17 stepper motor; 7) a set of plastic fasteners; 8) drive gears; 9) drive belt

This is a list of items you need to purchase. Hardcore users can assemble some of them themselves, but for beginners, I strongly recommend purchasing ready-made solutions.

Yes, you will also need various small things (studs, bearings, nuts, bolts, washers ...) to assemble the case. In practice, it turned out that using a standard m8 stud leads to low printing accuracy on the Z axis. I would recommend immediately replacing it with a trapezoid of the same size.

M8 trapezoid stud for the Z axis, the use of which will save you a lot of time and nerves. Available for order on all major online marketplaces

Customized plastic parts for the X axis must also be purchased, such as these from the MendelMax retrofit kit.

Most parts available at your local hardware store. On RepRap you can find a complete list of necessary little things with all sizes and patterns. The kit you need will depend on the choice of platform (we'll talk about platforms later).

What's the price

Before delving into some aspects of the assembly, let's figure out how much such entertainment will cost for your wallet. Below is a list of parts required for purchase with an average price.

Platform selection

The community has already developed a number of different platforms for assembling printers - the most optimal case designs and the location of the main elements, so you do not have to reinvent the wheel.

i2 and i3 are key platforms for self-assembly printer enclosures. There are also many modifications of them with various improvements, but these two classic platforms should be considered by beginners, since they do not require special skills and fine-tuning.

Actually, illustration of platforms: 1) i2 platform; 2) i3 platform

On the plus side of i2: it has a more reliable and stable design, although it is a little more difficult to assemble; more opportunities for further customization.

The i3 variant requires more special plastic parts to be purchased separately and has a slow print speed. However, it is easier to assemble and maintain, and has a more aesthetically pleasing appearance. You will have to pay for simplicity with the quality of printed parts - the body has less stability than i2, which can affect print accuracy.

Personally, I started my experiments in assembling printers from the i2 platform. She will be discussed further.

Assembly steps, challenges and improvements

In this block, I will only touch on the key assembly steps using the i2 platform as an example. Full step by step instructions can be found here.

The general scheme of all the main components looks something like this. There is nothing particularly complicated here:

I also recommend adding a display to your design. Yes, you can easily do without this element when performing operations on a PC, but it will be much more convenient to work with the printer this way.

Understanding how all components will be connected, let's move on to the mechanical part, where we have two main elements - a frame and a coordinate machine.

Assembling the frame

Detailed frame assembly instructions are available on RepRap. Of the important nuances - you will need a set of plastic parts (I already talked about this above, but I'll repeat it better), which you can either purchase separately or ask your comrades who already have a 3D printer to print.

The frame of the i2 is quite stable thanks to its trapezoid shape.

This is how the frame looks like with parts already installed. For greater rigidity, I reinforced the structure with plywood sheets

Coordinate machine

An extruder is attached to this part. The stepper motors shown in the diagram above are responsible for its movement. After installation, calibration is required along all major axes.

Important - you will need to purchase (or make your own) a carriage for moving the extruder and a mount for the drive belt. Drive belt I recommend GT2.

Carriage printed by the printer from the previous picture after it has been assembled. The part already has LM8UU bearings for guides and belt mount (top)

Calibration and adjustment

So, we completed the assembly process (as I said, it took me 150 hours) - the frame was assembled, the machine was installed. Now another important step is the calibration of this very machine and extruder. Here, too, there are small subtleties.

Setting up the machine

I recommend calibrating the machine with an electronic caliper. Do not be stingy with its purchase - you will save a lot of time and nerves in the process.

The screenshot below shows the correct constants for the Marlin firmware, which must be selected in order to set the correct number of steps per unit of measure. We calculate the coefficient, multiply it, substitute it into the firmware, and then upload it to the board.

Marlin 9 firmware constants0168