A heated bed for a 3D printer is necessary so that the molten plastic attaches better and does not curl or fall behind the platform during printing. At optimal temperature heated plastic expands slightly, and when cooled it contracts, and if the surface is very cold, our part will turn into waste. The heating table for a 3D printer has a hole in the center for a thermistor; if you use ABS material, set the heating settings to 100-110°C, for PLA it is not much less than 50-70°C. Anyway, everyone will customize the mk2b table for themselves and test the appropriate temperature, the current consumption is on average 5A.
An example of connecting a 12 V power supply - solder plus to value 1, minus to 2 and 3. Next, take a 3V LED and a 620-800 Ohm resistor and connect it as indicated in the picture. Now when heating occurs, the LED indicator will light up. Using thermal tape (it can withstand up to 300°C), glue the thermistor in the center.
In order not to overheat Ramps 1.4, we will connect it differently, for example through a 30A car relay (see photo). Thus, we only control turning on and off, and our relay already passes a higher current. If you decide to just collect, .
Very common complaints after purchase, such as a crooked 3D printer table; when viewed from the side, the plate is slightly curved. Yes, this happens, but there is nothing terrible about it! Fastening the 3D printer table - using 4 springs and bolts, attach it to the Y axis and tighten the springs, it will gradually straighten, and in the future the 3D printer table will be calibrated. To do this, we lower the Z axis to the very bottom, and move the X axis to any corner of the mk2b table and tighten or release the spring, we do the same actions with each corner so that the distance between the nozzle and the glass is the same.
For the glass for the 3D printer table, we take silicate glass (regular) 4 mm thick and press it along the edges with holders for office paper. You can buy a table for a 3D printer using the links below, there are also other components. One more thing, we reduce heat loss and speed up heating, we insulate the bottom of the mk2b table with non-flammable materials, cork backings, aluminum tape, etc.
Varnish for a 3D printer is needed for better adhesion of the model, you can use not only special ones, I recommend looking towards those that are easily refilled. See at the end of the video I show one of them, we worked with printing, finished, filled it in and let the printer work again. Hairspray for a 3D printer can be used for any purpose; with some, the plastic does not stick, while others set for a minute and then the part lags behind. Experiment!
I wrote about printing with ABS plastic on the cold bed of the MC2 3D printer from Master Kit.
The technology works, but it imposes some restrictions, primarily on the dimensions of the printed part in the horizontal plane. Having enjoyed experimenting with and tweaking the MC2 printer, I came to the conclusion that it was time for me to get a heated bed. Moreover, the printer electronics support this feature. And at the same time try to make this table adjustable by eliminating the AUTO_BED_LEVELING function. In principle, the function works well, I wrote about this in this article, but I wanted to try this option.
Actually, for this you only need to purchase the heater itself, the thermistor and springs for adjustment - this can be done on the website 3d.masterkit.ru. And figure out how to thermally untie plastic parts printers designed to mount the table, and a heater.
After rummaging through the cabinets, I found a piece of fiberglass. Good, smooth, 2mm thick. I sawed off a 220x220mm square from it. (The size of the heater is 214x214mm.) And, without thinking twice, I drilled 4 holes in it for M3x10 screws with a countersunk head for attaching the PCB to the standard glass holders and 4 holes for attaching the heater. I drilled 2.5mm holes in the parts for fastening the glass and screwed the textolite in place with screws like self-tapping screws.
Now you need to attach the heater to the PCB through springs. For some time I thought about how to make sure that the nuts of the adjusting screws were fixed, but then I decided to do without nuts at all. I cut an M3 thread directly into the fiberglass, it turned out to be about 4 turns. I tried twisting and unscrewing the spring-loaded screw several times. If you do this carefully, the thread holds quite well and does not deform. Let's see how the solution will behave during long-term use; If the thread deteriorates, I’ll glue a metal nut-washer with an M3 thread onto the PCB, I can print a retainer from ABS, or something like that.
Next, you should glue the thermistor into the central hole in the heater with heat-resistant tape or paper tape. It connects to the control board at connector T1. Also, the Marlin firmware must be enabled to read data from this sensor. To do this, in the Configuration.h tab you need to change 0 to 1 in the line #define TEMP_SENSOR_BED 1
After this, in the RepetierHost program you can see and set the table temperature value.
Glass for printing - how could we do without it - convenient to mount stationery clips for paper. They can be found in any stationery department. This is how the sandwich turned out. Quite weighty, I must say. I decided that in connection with this it would be necessary to reduce the acceleration along the Y axis, and at the same time the X. Let's get into the firmware again. And we halve the following parameters in Configuration.h (new values are indicated):
#define DEFAULT_MAX_ACCELERATION (4500,4500,100,9000)
#define DEFAULT_ACCELERATION 1000
It will probably be a little slower to type, but oh well, we're not in a hurry.
In order to eliminate the influence of the extruder fastening on the positioning accuracy and to fully realize the possibility of adjusting the table, I decided to rigidly fix the extruder in its holder, for which I drilled through the parts of its fastening and tightened it with screws. In this regard, I had to move the Z-axis limit switch under the platform on which the X-axis is implemented. I printed a part with two slots for adjusting the limit switch and simply glued it with dichloroethane to the base connecting the three stepper motors at the bottom of the printer. Just in case, I also tightened it with a screw. Now the limit switch is triggered when the platform is lowered to the desired level.
As a power supply, taking into account the increased current consumption by 10A (!), I used an abandoned power supply from an old computer with a power of 350W. It produces 15A current on the yellow 12V wire. We connect the heater to terminals D8 of the control board. I checked the voltage at full load, it stays at 11.5-11.6V. The block does not heat up. Good!
Let's now try to print something with ABS. Test cube 30x30mm, for example. We see in RepetierHost: 100 degrees on the table, 250 on the extruder. Layer 200 µm, blowing off.
It smells a little, but with the window open it’s quite tolerable. For me, let it smell, even pleasant!
It turned out to be a pretty decent cube, you’ll agree! By the way, when printing, I didn’t turn on the part blowing, so it cools the extruder by 10 degrees.
I was pleased with the print quality, but after a while I realized that my experiments had blocked my access to the control board! Adjust the driver current or switch something...that's an ambush. It turned out that if you loosen the fasteners and carefully remove the polished shafts along which the table moves, it can be removed in a remarkable way and provides access to the board. At the same time, all table settings with springs are completely preserved. Ugh!
So I haven’t decided yet which calibration I like best, auto-leveling or springs on the table...
Happy printing everyone!
Good health to all.
While looking through publications on the portal, I noticed the device for adjusting the printer table from different authors. Chinese lambs appear in almost all photographs of printers.
I would like to offer a device for precise and convenient adjustment. This device allows adjustment with an accuracy of 0.05 mm. The photo shows a set of adjustment screw jacks for the 3D printer table. Since this is a portal about 3D printers, a printed version of the device is presented here. The printed version is intended for printers without a heated bed. For heated tables, it is necessary to install a device made of metal.
The jack is installed at the corners of the table. The active screw is secured to the moving part using a lock nut with a Grover washer.
How is the presented jack constructed?
The figure shows the printed parts from left to right: Cover, Body, Nut.
A metal self-locking nut M3 is inserted inside the nut. The M3 nut is installed during the printing process and is tightly sealed with the following layers. This was done to eliminate possible gaps and backlashes.
This M3 nut eliminates thread play due to the presence of an elastic element pressed inside the M3 nut (shown in blue in the figure).
General scheme devices
The fasteners (screws) are shown in purple.
For heated tables, I offer jacks made of metal. They are much simpler in design. I have two design options.
The first option is manufactured as an independent assembly unit.
Consists of two covers, an active nut ( Brown color), and two spacer elements (I used regular nuts). I made the active nut from a 50 ruble coin from 1993. Works fine.
The second option is similar to the first, but instead of the bottom cover, a structural element is used on which the jack is attached. This simplifies the design, reduces the number of parts, but does not make it possible to use the device in another place.
Reading reviews of 3D printers on Muska caused a sharp itching just below the back. On the one hand, I really wanted to, on the other hand, the toad was choking to shell out a ton of money for a rather useless thing, and besides, they all looked worse than a nuclear war.
Then I sent my 11-year-old child to summer courses on design and 3D printing, where we tried printers from Ultimaker to , printed all sorts of useful things, and still decided that the toad could be persuaded :)
The problem of fear remains. Printers like Prusa take up a lot of space on the desk and stick out with all their guts. Therefore, when I saw reviews of the beautiful and fairly compact Micromake D1 printer (,), the decision was finally ripe.
Micromake D1 is definitely a beauty. The manufacturer boasts that all aluminum supports are first cut and only then painted, so that even the ends of the parts are processed. All of the plastic parts are factory-molded rather than printed, and even all of the included bolts come in black. Well, purely Darth Vader from Star Wars :)
The manufacturer offers 3 versions of the printer - on polished axes and the most expensive - on rails. Since all the motors are located at the base, the print head is lightweight, and the structure does not wobble or become loose during sudden movements of the motors. Therefore, I decided that overpaying for expensive options was a waste of money (and I was not mistaken).
The printer was ordered on July 10th after intensive correspondence with the seller (he has excellent English!) and studying it up and down. After 15 days I received the box from SDEK, all the issues with customs, therefore, were not on me (otherwise).
After a little haggling and applying a penny coupon, the printer cost me $225.
Everything was bought with my own money
Since I immediately firmly decided that I wanted to print with ABS plastic, which is harder than the other option - PLA, I ordered additional module - heated table.
The fact is that when it cools, the plastic shrinks slightly. The printer head takes plastic from the reel, melts it at a temperature of 230 degrees Celsius and through a head with a diameter of 0.4 mm squeezes it out layer by layer. work surface. If the bottom layer has time to cool, the shrinking part will simply bounce off the surface and printing will have to be stopped.
To prevent this from happening, ABS plastic is printed on a heated bed - in fact, this printed circuit board with one long snake track to which current is supplied. The board is made not on PCB, but on a thick sheet of aluminum and it actually works as a burner. On the same board there is a thermistor that controls the temperature. A sheet of glass is placed on top of the heated bed, and the entire sandwich is heated to 110 degrees.
To handle the increased power of the unit, you need to change the power supply to a powerful one. The manufacturer supplies a heated bed with a 12V 16.5A power supply - the whole set costs an additional $49.30. A funny moment - even though the seller gave a discount for the extra power supply, he still put the standard low-power unit in the box. Suitable for use on the farm...
Package
The whole set arrived in a flat box inside another transport box. Weight - about 8 kg. All parts are well packed in separate compartments, the racks are wrapped. For packaging - a solid A.
I won’t write in detail about assembling the printer - it takes about 4 hours if you have the right hands. right place and great care. Just download videos with assembly instructions, watch them in their entirety, and then assemble them. However, I warn you, your fingers will hurt from the hex wrench for another two days :)
The manufacturer carefully included in the kit a control board with an already soldered reinforced power connector, since it’s definitely not worth driving almost 7 amperes through a regular 5.5mm plug:
After assembling the printer, I started working on the heated bed:
Aluminum did not suffer from ideal evenness - I had to stick it on glass table sand and polish:
The wires and control board were protected with a layer of heat-insulating foam and, for reliability, with a piece of touching silicone culinary mat Pink colour, bought in Auchan for one hundred rubles. Please note that the manufacturer normally suggests mounting the glass of the desktop on a heated bed paper clips- three pieces were carefully attached:
Here's a problem:
It takes a long time for the heating to reach the required 110 degrees. No, not like that: LONG. About forty minutes. Since the aluminum “hot bed” fits tightly to the load-bearing frames and perfectly transfers heat through them to the atmosphere, it first warms the entire structure, and only then begins to slowly reach the required degrees. Also, heat flows away perfectly from the sides and from above.I dealt with the problem by covering the work surface with a silicone mat, but the solution turned out to be so-so. The heating stopped getting cold from any draft, but the heating speed did not improve much. I began to look for a way to make a “fur coat” for the heated bed and prevent heat leakage.
Heat transfer from aluminum to glass was improved by a third of the KPT-8 tube.
While looking for material for a “fur coat” I found non-standard solution: I took a cork sheet - a lining for the laminate, the scraps of which were left over from the renovation. Also, for the first time in 20 years I had the opportunity to pick up a compass :)
As a result, the heated bed turned out to be wrapped in a layer cake made of several sheets of cork, with only glass sticking out. I drilled out the mounting holes so that the screws with the heat-insulating tube put on them would fit into them. The washers were also insulated from the heating plate with silicone rings to reduce heat transfer to the frame.
The result is that the table warms up to 70 degrees in 5 minutes, and in twenty it reaches the operating mode of 110 degrees.
And the result?
To test the printer, I took a well-known test model from Thingiverse::
I typed, default settings. Printer after automatic level adjustment:
Separately, a view of the sole of the model:
The layers, if you look closely, are visible, but if you consider that the product was not subjected to either “skinning” or “acetoning”, the result was decent:
As a result, I am very pleased with the printer. Due to its design, it is quite difficult to calibrate for printing models with a sole more than 10 cm in diameter, but it allows you to print pieces up to 32 cm in height. To print small models, just stick it on glass masking tape from the construction market - and the result is invariably excellent. The main thing is that now the child cannot be pulled away from the unit - it makes models and prints them right away. It helps a lot that Thingiverse has a huge supply of models for installing Arduino sensors - and you can move from “knee-length” models with wires sticking out on the sides to more solid crafts.
I'm planning to buy +20 Add to favorites I liked the review +29 +51Hello forum residents!
This article is not a 100% recipe for creating a desktop hot desk, but only an attempt to implement a spontaneous idea.
All 3D printer owners are familiar with this textolite heating table, I also purchased it and was disappointed. It is impossible to obtain a temperature above 80°C with its help. While harsh printing veterans recommend a temperature of 110°C when printing with ABS plastic.
Accordingly, a more powerful a heating element. A search for a 220V silicone heating element gave results of 1500-3800 rubles per copy. Considering that I spent 2000 rubles on the entire printer. this is unacceptable.
And now we actually got to the idea itself. Assemble the heating element yourself from available materials, namely nichrome and ceramics.
Calculation of a 350W element.
I decided to limit the voltage with a rectifying diode, the voltage will be 110V peak and 55V conditionally average. (please don’t argue this is an idea).
Online length calculator nichrome wire http://forum220.ru/calc-nichrome-wire.php
Entering data
Thickness 0.8mm
Power 350W
Voltage 55v
We get the answer: the length of the wire is 3.93 m, the current is 6.36 A.
That's what I needed, in fact, I selected the thickness of the wire so as not to wear myself to death. For example, if you do not limit the voltage with a diode, then with a nichrome thickness of 0.8 mm you will have to distribute 62 m of wire on a surface of 200 * 200 mm.
And so the distribution is 4m/0.2 and that’s 20 threads, that is, we lay the wire every 1 cm.
We are approaching the choice of a mixture for the base of the element, in general it should be ceramics, but forget about it, it is impossible to make it at home, so we go to the store.
At first I chose glue for stoves and fireplaces, it dried poorly and was very fragile, and then I found out that it also heat insulating material. (Who needs a bag of glue for the fireplace, write in a personal message)
The next one was gypsum, it is also a good heat insulator, and also fragile. I decided to place the wire as close to the surface as possible. I tried to do the winding on plaster stumps, but it didn’t work out.
So I bought a board and filled it with nails, this allowed me to tightly tension the wire close to the “heating” surface.
After which I filled it with plaster not reaching the nails and reinforced the structure with 9 bamboo skewers.
After hardening, I transferred the structure to a mirror, crimped copper wires, erected a “formwork” of cardboard and filled it with a large mass of plaster. It dried for a week, but not because I’m patient, I just didn’t have time.
I bought a plug with a cord in the store, re-soldered the hot table relay, found a thicker diode in the bins, soldered it in series, cut a 5 mm nichrome thermocouple into the body of the plaster. It's time to turn it on.
I knew that plaster is never dry. But I decided, “Right now I’ll set it to 50 degrees, or maybe 90 degrees, and everything will dry out in a day.” I installed it and turned it on. Dear children and everyone who should not touch wires, this article discusses working with life-threatening voltage of 220V. Therefore, be sure to ensure that all connections are secure and sufficiently insulated.
Hellish hissing and screams of damned souls (whoever fried waffles will understand me) came from the printer, the stove bent into an arc, red threads of nichrome protruded from its body, and the stove itself was covered with perspiration. I was dumb for about five seconds before I pulled out the socket of the hot table, and the switch was still closed, the thermocouple showed its 32°C, and was very slowly gaining temperature.
So the results are unsatisfactory, what’s wrong:
The nameless diode suffered a breakdown and died, as a result of which all 220V went to the table.
The thermocouple is too far from the nichrome filament and does not respond to heating. (gypsum thermal insulation)
Reworking:
Fit the thermocouple tightly to the nichrome thread and fill it with thermal paste.
We set the diode to 10A 600V.
Turn it on.
The temperature jumped over 250C, the panel went into error.
The results are unsatisfactory, what's wrong:
The power of the table is excessive, design errors. The average voltage value is 86V, not 55V as expected.
The temperature check in the firmware is set to 5000 milliseconds, which is too much for our table, we set it to 500 milliseconds.
Checking the table temperature once every half a second gave results: the table worked as it should, but with “kicks” by 15-18 degrees. This does not allow the firmware to adequately handle the heating of the table in G code, that is, it waits until the temperature settles down endlessly. I also placed a silicone mat to transfer heat more evenly to the glass.
This is what happened when installing 120co, I knew that this could happen but not to me. As a result, you need a silicone mat covering the entire surface and glass no larger than the heating element.
The problem of aligning this “brick” is still not solved, but I think it will be solved in the future.
This brick is not suitable for those whose printer drags a table along the X axis; it is very heavy.
And the way the idea came about, you can even make it thinner.
In conclusion, do not be afraid to implement ideas while stumbling over far-fetched problems, analyze and solve problems as they arise and you will succeed.
I take this opportunity to say hello to my fellow countrymen from Bestfilament and wish them good luck in all their endeavors.
