I've already reviewed several kits that let you build all sorts of useful things for radio amateurs. But today I'm reviewing a bigger kit. We're going to try building a recent invention: a 3D printer. I can't say everything went smoothly—I was constantly waiting for something to go wrong—but in the end, I managed to get something working. Anyway, a description of what this is and an attempt at a step-by-step guide are below the fold.
First, I want to make one thing clear. I'm not a 3D printing professional; this printer is the first one I've ever seen in person. Of course, I'd seen pictures and videos of printers at work before, but seeing one is very different from using one yourself. So this whole review will be written from a beginner's perspective. I'll try to explain and show everything I've been able to learn and understand. Hopefully, that will make things easier for anyone else seeing a printer like this for the first time.
There are more experienced folks here who've already eaten printed a lot of dogs, so here's a request: if you spot any obvious nonsense, don't get mad—just let me know what I should change or add to the review.
First, a little introduction. We'll be looking at an FDM (Fused Deposition Modeling) 3D printer. This technology works by having the printer deposit (melt) thin layers of plastic on top of one another. There are other technologies, but they're usually more complicated and/or expensive, and less common, so I won't cover them here to keep things focused.
Printers also differ in how their mechanics work. Broadly speaking, despite the wide variety of designs, FDM printers can be divided into two groups. 1. The standard three-axis design 2. The “Delta” design.
There's a reason I've split them into these groups; let me explain. Although the most common designs look different, formally they're the same. Even the control board is the same, because the operating principle is identical: it moves the print head relative to the model. Whether we move the model relative to the head or the head relative to the model, raise the bed or lower the head, makes absolutely no difference—it's purely a matter of mechanics. To avoid copyright issues, I got the printer diagrams from here. Beginners may also find the information here useful. The printer under review uses the design shown in the center.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
And as I mentioned above, Delta printers are a separate category. They have their own advantages and disadvantages compared with the designs above. The advantage is that they're better for printing tall models; the downside is more complicated calibration and a small print area, limited by three intersecting semicircles.
In this review, I'll describe everything from the box to the finished print. Along the way, I'll show all the components and explain some of them: what they are, what they're for, and how they work.
First, the packaging. Since it's large, I've hidden it under a spoiler.
When the box was delivered, I wasn't particularly surprised by its size, though I can say for sure that it's really quite big. My trusty matchbox just disappeared against it :)
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The package measures 540 × 460 × 225 mm. Overall, the box is about the size of a computer tower.
The product page listed the total weight as 11 kg. At first, I thought it would probably weigh less in reality; weights are often “padded” for various reasons. But clearly not in this case—the box really did weigh 11 kg.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
But I was genuinely a little surprised by what came next: inside this box was a second one. The outer box was simply extra protection to make the contents more robust against the hands of careless delivery workers. Well, that's a point in its favor :)
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The inner box has the printer's name on it, too, though for some reason it's 3DCSTAR.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
All the components are neatly arranged in three trays made of expanded polyethylene.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
Let's take a quick look at what's in the trays. Top tray This one holds the control board and display panel, a few screwdrivers and small wrenches, as well as the vertical mechanisms and acrylic frame parts.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The “second” level holds the bed and a whole bunch more acrylic frame parts. The bed is glass, so placing it in the center of the package makes perfect sense.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The bottom “level” contains the metal rails and lead screws, along with the motors, extruder, power supply, and various small parts.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
Extruder
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The motors are packed snugly in their own little “pockets.”
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
Overall, I have absolutely no complaints about the packaging. It would be very hard to damage anything—no question.
The printer came with a control board that “runs” everything: the motors, bed and extruder heating, signals from all the endstops, and so on. It's a very common board; I've seen it sold separately, which makes a fully DIY build seem like a real possibility. The boards probably differ in their firmware, but I don't think that's critical. A MicroSD memory card was also included. The printer model and firmware version were printed on its packaging.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
I'll put the following description of the board and its components under a spoiler.
The motor driver chips are located on the left side of the board (as far as I can tell, Allegro A4988), with small heatsinks attached for better cooling.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The right side houses the actual “brains” and the transistors that control power to the heaters and fans.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The underside of the board is bare, with only traces.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
A few group shots. 1. AtMega1284P processor 2. A closer look at the drivers. Each driver has a trimmer resistor for adjusting the motor current. 3. The board also has a USB VREG jumper. I left it alone because I couldn't even figure out what it was for. There's a Reset button next to it, which I never needed during the entire time. I only remembered it when I was sorting through the photos for this review. 4. The transistors that switch power to the heated bed and extruder also have small heatsinks.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
1. The fans are connected through their own transistors; heatsinks aren't needed here because the current is low. 2. The USB connection is handled by an FTDI FT232RL chip. I initially expected to find the familiar PL chip. 3. There's a 74HC4050 logic-level converter chip. It converts high-voltage input signals to logic-level signals that are safe for the microcontroller. 4. A connector for in-circuit programming and, as far as I understand, connecting additional devices.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
All connections use plug-in connectors. The motors for the X, Y, and Z axes connect on the left, along with the extruder motor E. The Z-axis connectors are wired in parallel because there are two motors, which run simultaneously. The flash card was already in its slot. There wasn't much of interest on it: assembly instructions and a couple of models for testing. It's an unbranded 8 GB card. The MiniUSB connector for connecting to a computer is next to it. The printer can print from a memory card or be controlled directly from a computer.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
Now we can move on to the assembly process. I've divided the process into chapters, following the instructions, although in practice it turned out not to be as linear as I initially thought. The descriptions will follow this format: Instructions, required parts, sometimes a brief explanation and description of the parts, and the completed assembly.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The motor is in the same tray as the other motors, on the bottom layer of the packaging. The acrylic parts and a bag of fasteners are next to it.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
There were two bags of fasteners; at this stage, we need the larger one. An Allen key and possibly a screwdriver will also come in handy. The kit included a bunch of different tools, but in reality I didn't need more than half of them.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
Unfortunately, all the fasteners are dumped together in one big pile. I think some kind of sorting would have helped.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
I was surprised by how many fasteners there were. I tried to figure out why they included so many, but figured that if they were in the kit, I must need them. Turns out I was wrong—there were lots left over.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
For some reason, they included a bunch of tiny self-tapping screws in different sizes and shapes. I only ended up using two. To make assembly easier, I sorted the fasteners into separate bags by size or type. I recommend doing the same; assembly is much more pleasant that way.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The instructions specify the length and diameter of the screws throughout. Just in case, here's a reminder of how to measure the length of countersunk and regular screws.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The kit includes four SY42STH38-1684A stepper motors: a pair for driving the toothed belt (left), and a pair with dampers already installed (right). For this step, use the motor shown on the left in the photo.
Stepper motors are used in 3D printers because their rotation angle is easy to control, which is important for positioning accuracy. The motors included in the kit are quite powerful. I've seen people modify the printer to use less powerful motors, but I don't see the point: if a motor occasionally skips steps under load (you'll hear a fairly distinct click-click sound), the print will come out wrong.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
So, take the acrylic part shown in the photo, the motor, four 10 mm screws, and an Allen key. The assembly process gradually got more challenging: it started with the simple stuff, then got harder and harder. I found that quite convenient.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The assembly is complete. In the photo, the motor wires come out at the top, but in practice I found it better to have them point down (rotate the motor 180 degrees during installation).
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
On the bottom “floor,” find the bag with the small acrylic parts and the piece with a bearing; on the middle floor, find the part shown in the photo below.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The kit contains lots of different small parts. For this step, you need a pair of the ones on the left. These parts will later hold the metal guide rods in place.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
All the required parts are shown in the photo. These use Phillips-head screws rather than hex screws.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Join the parts, then—after a bit of fiddling—insert the nuts and secure the assembly with the screws. Tighten them firmly, but don't go overboard; the parts should be held securely. Sometimes these joints have small bits of leftover acrylic in the corners, so if the parts don't fit snugly, check for excess material and trim it off. I came across this about three times during the whole build.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The assembly fully assembled.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
In the top section of the packaging, find the limit switches with their wire harness; in the middle section, find the acrylic part shown in the diagram.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
There are two types of switches: two large ones and one small one. Either of the large ones will work for this step. They connect via terminals, which may make replacement easier.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
For the next assembly step, you'll need everything shown in the photo: the motor from assembly step 1 and the small acrylic parts from step 2.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The switch is screwed onto one of the small acrylic pieces, as shown in the photo. Shorter screws would have been enough, but I followed the instructions, so I used the long ones.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The assembly is fully put together. There's one screw left over; I never figured out what it's for. It's shown in the diagram, but there's nowhere to put it.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
On the top layer of the packaging, we find three bags of linear bearings; the bed itself is on the middle layer.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
In the description of Step 1, I mentioned that there were two bags of fasteners, one large and one small. Now it's time to open the small bag. Inside, we'll find a pile of assorted screws, a few springs, and knurled nuts that are easy to tighten by hand.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
First, we'll need the bed frame, which is stored under the glass bed, three bearings, and some of the fasteners.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Take the frame, three bearings, and twelve large-diameter screws. Yes, there are exactly three bearings, not four as you might expect. Nothing is missing; that's just how it's designed. Sometimes four are used, but three are usually enough.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Screw everything together as shown in the photo.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The package also included a heater, in addition to the glass bed. The bed needs to be heated to get better print quality. Sometimes just a little, and sometimes up to 100–110 degrees (for example, when printing with ABS). The manufacturer came up with a very simple solution: the heater is a circuit board with traces. As we know, when current flows through a conductor, it heats up. Usually that's a bad thing, so we try to reduce the heating by making the traces thicker and wider. In this case, though, the heat is exactly what we want. The traces are laid out to heat the board evenly, with the glass bed on top. There are also versions where the heating zones can be controlled, so you don't have to heat the whole bed when printing small parts. But that makes the design and control more complicated, so it's rarely used.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
I mentioned above that the bed is made of glass. Metal beds were often used in the past, but they could warp during operation, which interfered with proper printing. Glass beds came into use after that; they are less prone to thermal deformation. To help the model stick to the bed, it is recommended to cover the surface with blue painter's tape. This tape is made by 3M. They say you can buy it at a home improvement store. I couldn't find any, so I'll order it online. Apparently, it's a real rarity in our city of 1.5 million people. Fortunately, the kit manufacturer thought ahead and covered the bed with the necessary tape. There's enough for testing and printing the first few models, but I'll need to buy more later. Tape 50 mm wide is more convenient to use.
But the tape I applied extended quite a bit over the underside, so to improve the fit and make it easier to peel off, I decided to trim the excess first. The easiest way to do this is with a ruler and a utility knife. I'm also thinking of applying some thermal paste where it contacts the heater.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Use 30 mm screws and nuts to fasten the heater and bed together, then put the springs on top. My kit came with five springs instead of four—a sensible choice, since springs have a way of getting lost :( The temperature sensor is taped to the underside with the same blue tape; it helps monitor the heater temperature.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Assemble the whole thing. I even had a few spare parts left over. But tightening it all together was a complete waste of time, since I didn't know I'd have to take it apart again later. So I'd recommend simply skipping the last step.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Find the small parts on the top layer, underneath the large acrylic piece. Then take the two motors with their damper mounts from the bottom layer.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The photo shows the parts needed to assemble one drive. You need two such sets, one for the left side and one for the right. As you can see in the photo, the right-hand acrylic piece is asymmetrical and has an extra hole beside the large main one. The instructions didn't mention this, but during assembly I decided to orient the parts so that this hole would be on the left for one set and on the right for the other, just in case. That turned out to be the right call: when installing these assemblies, one hole needs to be on the left and the other on the right. Keep this in mind.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
At first I didn't know what the bosses attached to the motors were; I thought they were solid parts. It turned out they are damping elements. They have a slot and can flex slightly when pressed. When installing them, I positioned them so the bottom of the damper extended slightly beyond the acrylic housing.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The two nearly identical assemblies are ready.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
Up to this point, we had been assembling small components, but there's no way to call this part small. Find the largest part of the frame (you can't miss it), the corner pieces, the power supply, and the large limit switch. You'll also need a couple of small acrylic pieces from assembly step 2 (the same ones used there).
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
There's not much point in going into detail here; it's very hard to assemble it incorrectly. The printer's name printed on the frame serves as a guide. Printer frames are sometimes made of metal, sometimes acrylic; early enthusiasts even made them from plywood and particleboard. A metal frame would of course be better, but this one is made of acrylic about 8 mm thick. It holds up pretty well when properly secured with the included hardware; I didn't notice any play. On the other hand, by the end of the assembly my whole table was covered with the protective paper from these parts; the photo shows only a small portion of it. Another downside of acrylic is that it looks nice when you peel off the protective paper, but after a while it loses its good looks :(
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
Since the printer came with a power supply, of course I'll tell you about that too. The power supply has the usual metal case and passive cooling. According to the label, the PSU is rated for an output voltage of 12 V and a maximum current of 20 A. This PSU is brand new. I received the kit a couple of days before New Year's, and the PSU's manufacture date is December 2015.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
I'll put the teardown and inspection under a spoiler. Power supply teardown and analysisAt first glance, this is a very ordinary PSU. I've reviewed many similar ones, so I'll just go through what a decent PSU should and shouldn't have.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
A terminal block for connecting the wires is mounted on the side. The output has four 2200 µF capacitors rated for 25 V, giving a total filter capacitance of 8800 µF. I wouldn't call that great, but it's quite acceptable for a PSU like this.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The input has a full-fledged mains filter, with interference-suppression capacitors both before and after the inductor—a rare feature in inexpensive PSUs these days. The ceramic interference-suppression capacitors are the correct Y1 type. The bridge rectifier is rated for 800 V and 6 A, and an NTC thermistor provides inrush current protection. The board also has a 110/220 V input voltage selector. I usually recommend desoldering it, but it's awkwardly positioned here, and you can't switch it without an extra tool.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The input filter capacitors are labeled Rubicon, but judging by the fact that they’re marked 470 µF and actually measure only 317 µF, they’re probably counterfeit. The total input filter capacitance is about 160 µF, which is a bit low for a 240 W power supply :( The inverter transistors are pressed against the case, which acts as a heatsink. They’re ordinary transistors with a standard mounting arrangement, though they’re installed a little crooked. The transformer is marked 12 V, 20 A, which generally matches the stated specifications.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The power supply is built around the classic TL494 PWM controller, so it’s easy to repair, although its performance isn’t the best. The output diode is also pressed against the case, but here a small heatsink has been added as well. That’s justified with an output current of 20 A. I’ve seen this even in 5 A power supplies, where it seemed a bit unnecessary. The output inductor is wound with two wires and is about the same size as those in the other power supplies of similar power that I tested. Although the power supply is designed for passive cooling, there’s a connector on the board for a fan. It might come in handy, but I didn’t find any overheating issues. There’s a trimmer near the output terminal block for adjusting the output voltage. It was initially set to about 12.2 V, but during testing I turned it up to 13.5 V without encountering any problems.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Overall, I had no major complaints about the power supply. The only thing I didn’t like was the input capacitor capacity, which is lower than it should be. I’d recommend replacing them; fortunately, it’s easy to do.
You’ll also need a display at this stage. This is the little gem they included :)
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The board is very simple: it has the display and five buttons, plus a few resistors (presumably pull-ups), and that’s it.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
While inspecting it, I noticed a flaw. The front panel, which is also 3D-printed, is coming away from the acrylic frame. Once I peeled off the front panel, the problem became clear: the screw heads holding the whole assembly together weren’t recessed enough, so the front panel wouldn’t sit flush. I recessed the screw heads, applied new tape, and now it looks great :)
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
At this stage, we simply install the power supply, display, and endstop on the frame. The power supply is secured with three screws; the fourth hole is left hanging in midair.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The endstop mounting holes are slots for adjustment. I initially installed it in the top position, but during adjustment I had to move it almost all the way down.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
For this, you'll need the frame assembled earlier and the drives from Step 5.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
First, feed the wires through the special holes, and only then install the drive. One of the six mounting holes was slightly misaligned, but I didn't have to modify anything; the screw was just a bit tight. I also had to file off some burrs on the acrylic at this stage, because one of the drives wouldn't sit flush (I mentioned this issue at the very beginning of the assembly).
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The instructions clearly rush things when it comes to installing the power supply. Without a long screwdriver, tightening the top screw was very awkward. I recommend installing the power supply after the drives.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
At the very bottom of the box, find the rods and threaded rods bundled together. For this step, we need 8 mm diameter, 400 mm long threaded rods.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
For this step, you'll need the frame from Step 7 and the assembly put together in Step 3. You'll also need a wrench, which isn't included (too bad).
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
First, screw on the rear section with the motor.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Next, thread one nut onto each threaded rod and add one washer. Insert the rods as shown in the photo, then add a washer, two nuts, and one more washer.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Next, take the assembly from Step 2 and screw it onto the protruding threaded rods. I first tightened the rods as shown in the photo, but it's actually easier to secure the front section first.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
After that, manually set the distance from the front of the frame to the inside of the front piece to 220 mm using the nuts. Then tighten the nuts from inside the frame with a wrench, so you don't disturb the measurement you just set. Next, turn the nuts by hand toward the back, and finally tighten them with a wrench at the back of the printer. Make sure nothing gets skewed or bent in the process, or the acrylic parts may crack. I've described an assembly method that makes it very difficult to overtighten anything: the distance is set by hand, and then the nuts are tightened with a wrench without deforming the parts.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Find the 380 mm unthreaded rods, and get the bed assembly we prepared in step 4.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Take our assembly apart, separating the bed from its frame (the part I mentioned at the end of step 4), and watch out for the springs.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Move the retainers at the front (or back) out of the way, partially insert the rods, and slide them through toward the opposite side of the frame and into the linear bearings. This is how you fit the bed frame. Close the retainers.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The kit included a bag of various soft parts. We need one timing belt from it. You can't mix them up, since there are only two belts and they're identical.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Not only are they identical, but they also gave us plenty of extra length (at least for this axis). At first I secured the belt with two small O-shaped clips and cursed a lot, because it was incredibly awkward, but I was following the instructions. I had to tension the belt with one hand, turn the screwdriver with the other, and hold the nut on the other side with a third hand. :)
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
I didn't cut off the excess belt; I simply wrapped it around the frame and secured it with a cable tie. While you're at it, adjust the position of the toothed pulley on the motor so that the belt stays closer to the center at every bed position (see the photo at the top right).
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
At the very end of the assembly, when I could see which parts were left over, I noticed one that would work perfectly for the table frame.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
So I reworked the bracket the way it was apparently intended to be used. The part needed for this is at the bottom left of the photo.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
One of the key components of a 3D printer is the extruder. Its mechanism pushes plastic filament through a heater, producing a very thin strand with a diameter of 0.2-0.5 mm, depending on the nozzle installed. Extruders are usually designed for one of the common filament diameters: 3 or 1.75 mm. The kit came with an extruder for 1.75 mm filament. Sometimes the heater and feed mechanism are separate, with the feed mechanism fixed in place. This reduces the weight of the X-axis assembly and thus improves print quality, but the design is a little more complicated. The kit also included a fan, heatsink, protective grille, and mounting hardware.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The extruder mechanism is visible in the photo. At the top right is a pedal-like pressure mechanism. Pressing it moves the roller away from the toothed shaft so you can feed the filament in. When you release the mechanism, the roller presses the filament against the toothed shaft, and the motor can feed it into the extruder (heater) as it turns. The printer's electronics can also run the motor in reverse, but I never used that mode.
You can also see an additional fan on the right, used to cool the part after it has been printed.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The fan is needed to cool the upper part of the heater, creating a thermal barrier. The bottom is hot, the top is cool. This keeps the plastic from melting too soon, so it only melts at the very bottom of the heater. It also protects the mechanism from heat. I wasn't happy with the heatsink being held by just two screws, so I also applied some thermal paste to the contact surface.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
This is what it looks like assembled. I had a few washers left over, so I put them between the plastic standoffs and the heatsink.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
At this point, I ran into a small problem. The kit came with two threaded rods, 350 and 440 mm long, although the instructions called for a 380 mm one. After trying them out, I figured the 440 mm rod was the right one, so that's what we'll use.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
This is also the first time we need self-tapping screws; they hold the switch in place.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
Attach the last remaining motor and the switch to the plastic guide. I was really surprised they didn't make slots for the mounting screws; that would have made it easier to adjust the belt tension.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
Put the whole assembly together. The guides are 3D-printed and have a minor defect in the holes for the threaded rods. You can fix it in half a minute with something sharp.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
This part is easy: take what's left and put it all together :)
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
First, insert the smooth rods, installing the X-axis drive at the same time
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Then insert the threaded rods, screwing them down along the threads.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Then tension the belt, securing it with cable ties as you go.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
This is incredibly awkward to do. I ruined a pile of cable ties before I got it right
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
I was about ready to start swearing out loud, but some time later (the printer was already able to print) I found instructions showing how to do it. The manufacturer also suggested using cable ties. I swore, but more quietly.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Make all the connections exactly as shown in the diagram. I didn't have to redo anything while connecting it all; everything worked as intended. All the motors turned in the right direction, and all the endstops worked as they should. I was even a little surprised, since I kept expecting something to go wrong.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
I didn't like the original wires, and the 220 V cable wasn't suitable at all, so I replaced them. For the 12 V output, I used 2.5 mm² ШВВП cable, since the original one seemed a bit too thin.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Secure the cable with the included clamps
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The assembly is almost finished. Time for the first power-up. Nothing went up in smoke or exploded. The printer powered on silently, but after a short while the extruder cooling fan slowly started spinning faster.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
For obvious reasons, I wasn't happy with this mess of wires. The kit included a special sleeve, cable ties, and clamps to help sort it all out. There weren't enough clamps, and I even had some sleeve left over. Route the wires so that they won't get caught under the heater or in the mechanisms, no matter how the printer is positioned.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Coil the sleeve into a loop so it stays out of the way, then gradually wrap it around the wire bundles.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
To make the connections easier, I cut the wire ends to different lengths and brought them out one by one. I initially thought about shortening the excess wires, but in the end I just folded them up and tucked them into the sleeve.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Almost done
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
I also didn't like the wire connecting the heated bed. I found some soft speaker cable at home and decided to replace it.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
And while I was at it, I routed it a little differently, out to the side. By the way, there are two LEDs on the board. To avoid having to check the polarity, they're connected in opposite directions, so while the heater is on, one of them lights up.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Let's tidy up this wire bundle too
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
While I was at it, I secured the wires from the switch. The design is really poor—the wire keeps trying to get caught in the lead screw. You can see on the left in the photo how I had to secure the wire. It no longer gets in the way, but everything is a bit too close for comfort. I’m thinking about how to improve it.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The printer is now fully assembled. Here’s how it should look.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
And here’s how it turned out.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
Here you can see how my bed wiring differs from the recommended setup. I thought this way was better.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
As I mentioned above, I thought they’d included far too much hardware. I was right.
After assembling the printer, I had left over: 115 M3 nuts (shocking—I really didn’t expect to have this many left) 2 meters of cable sleeving About 25 assorted screws and around 15 different self-tapping screws (a reminder: I only needed two from the whole pile) 4 hex keys in different sizes Two screwdrivers (the large one was pretty badly worn by the end of the assembly) and tweezers A power cord and wires for the heater (I replaced them with different ones). Three acrylic parts: two for attaching the belt to the extruder (not needed) and one for attaching the belt to the bed (it turned out to be extra).
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
Almost forgot: they included parts for assembling a filament spool holder.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
There was another snag here: the axle made from tubing turned out to be too short. You can see it at the bottom right.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
I took a standard furniture tube and made a longer one.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
There, all done :)
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The printer's main menu. Press the up/down buttons to view the printer's current status. The photo shows the print time after a few quick tests.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
But what we're interested in is calibrating the printer—or, more specifically, the bed, and more specifically still, the distance between the bed and the extruder. To do this, press the middle button, go all the way down, press right, then press it once more. This takes us to the calibration menu. It lets you perform six basic operations: 1. Move all the mechanisms to their home position 2. Position the extruder over the bed's four corners 3. Set the nozzle height above the bed. The default is 0.2 mm; you can change it, but only until the next move. To activate the desired mode, press the right button, although it would make more sense to press the middle button, «Enter».
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
First, do the following: 1. With the printer switched off, set the same distance from the X-axis (the horizontal rails the extruder moves along) to the bottom of the frame on both sides. Do this by turning the motors on each side by hand. 2. Tighten the bed nuts a little more than necessary (so the spring coils are visibly compressed), but make sure the bed doesn't bottom out against the supports underneath. 3. Switch on the printer, open the settings menu, and use the «home position» and «any specified position» operations, along with the adjustment screw shown in the photo, to get the bottom of the nozzle just above the bed surface.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Next, select extruder positions 1, 2, 3, and 4 in the menu to move it to each corner of the bed in turn. Slide a sheet of paper between the nozzle and the bed, and turn the adjustment nuts until the paper pulls through with a little resistance.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Adjusting it was a bit awkward until I put a 40 mm-thick piece of countertop under the printer :) The thing is, my floor is laid over OSB and has a bit of give, while the printer's design calls for a rigid base. After that, everything went smoothly.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
Since I'm a complete beginner at this, I read a few guides and started loading the filament by inserting it into the hole and pressing the «down» button in the filament feed controls. That was a big mistake: the filament wound around the toothed shaft, and I had to remove the heatsink. Then I figured it out: press the lever on top and simply feed the filament in. It's best to cut the end of the filament at a 45-degree angle and straighten a 6–7 cm section. Then press the mechanism (holding the bottom of the extruder with another finger) and push the filament in as far as it will go. You'll probably need to wiggle it a little to get it farther in. That's it—you can release the mechanism. By the third or fourth try, it becomes almost automatic.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
The printer can print from either a memory card or a computer. For reliability and convenience, printing from a memory card is recommended, but I found it more convenient to print directly from the computer. A MiniUSB-to-USB cable was included for this.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
Below are some photos of the first parts I printed on this printer. At first, I didn't even know what needed adjusting on the printer. Even the nozzle was set to 0.5 mm, rather than the actual 0.4 mm. So the process went something like this: I tried printing with ABS, but nothing came out (even though I'd read that it's better to start with PLA! But who listens to advice?). Then I loaded PLA. I started a print, got my first part 10 minutes later, and then I was off and running.
I printed using Repetier-Host, with Slic3r as the slicer.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The first little box is on the left, the second on the right. The part measures 20x20x11 mm. Before printing, I checked that the travel distances along the axes were correct. I found a 1 mm discrepancy over a 100 mm travel distance, i.e. an error of 1%.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The first little box is on the right, the second on the left. You can see in this photo that the first part has a defect. After printing it, I raised (or lowered—I don't remember now) the extruder a little and got the second part without that defect. The black spot is just dirt; it got there later.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
The defect was on the first layer. On the left, you can see that the adjustment helped, although it didn't eliminate the defect completely. But these were just my first attempts.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
Just a photo
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
I deliberately tried printing small parts. I think this makes it easier to judge the print quality. After the little box, I printed a couple of gears. The right-hand gear has a defect in several of its bottom layers. It was printed in another corner of the bed, after only a rough adjustment.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
A little ring with a face
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
You can see a defect on these tabs; apparently, the temperature or feed rate was set incorrectly. For a printer where the temperature is set only by eye, I think it’s not bad at all.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
More photos
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
Since the problems were with the first layer, I experimented with a fairly handy model—the SIM card adapter—to simplify the process and use less filament.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
This is ABS filament. To get a good result, I had to study the printer settings—or, more precisely, enter the settings in the software according to the instructions. These are still the first parts, though. I printed them with the cooling fan on because I didn’t know any better. The purple parts clearly show the difference as I adjusted the settings. The problems were caused by the part coming unstuck from the bed; after that, the print goes well.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
A thermal camera helped me figure out part of the problem. I took several temperature measurements in different areas and saw that the bed needed some work. The printer was set to a bed temperature of 85 degrees and an extruder temperature of 210 degrees. 1. The bed immediately after the sensor reaches the set temperature 2. The bed after 5 minutes 3. The bed after 10 minutes 4, 5. The extruder 6. The power supply after 20 minutes of operation
The photo shows that the bed doesn’t reach the target temperature. Heat from the heater has to pass through the PCB and then the glass, while the temperature sensor is located right next to the heater. The temperature is very uniform, though. The extruder is 10 degrees short, but this is probably just a measurement error, since the nozzle’s emissivity is likely below 0.95. The power supply doesn’t get very hot. The hottest components are the snubber circuit resistors, which is normal.
ZONESTAR P802, aka Prusa i3, or building a 3D printer from a kit
And of course, a video of the printer in action, along with photos of the parts it made.
A brief introduction. The video didn’t turn out very well, but honestly, I didn’t expect video editing to be so difficult, even for something this simple. The last time I worked with Ulead, but I had to make this video in Pinnacle, which absolutely refused to process the whole thing in one go. I then joined the clips in VirtualDub and added the audio there, which I’d prepared in the ancient WaveLab. On the plus side, I found out that the computer from this review encodes video at the same speed as my Core 2 Duo E7500 and GeForce 240.
Below are three videos. The first and second are sped up 5 times; the third had to be sped up 7 times. I used PLA filament and Repetier-Host software. For the first print I used the Slic3R slicer; for the second and third, CuraEngine. I’ll talk about the software in the second part of the review.
1
This little thing is used to conveniently bend resistor leads.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
2
This is a part for cleaning dust off the plastic filament. It's highly undesirable for dust to get into the extruder, as it can cause printing problems. Some even recommend not removing the filament from the extruder after you're done printing
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
3
A little cat.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
At the bottom right is a photo of the area where dust got in.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
A group photo to show the size of the finished parts.
ZONESTAR P802, also known as Prusa i3, or building a 3D printer from a kit
So, what can I say in conclusion? First, here are a couple of answers to questions you might have: 1. Why is this review so long? I wanted to put together a Russian-language assembly guide with pictures and show the whole process at the same time. 2. Why is this review so long, and where are the instructions for configuring the software and printing? Including that would have made the review even longer, so I planned a second part where I'll show and explain everything. Besides, I'll get a little more experience and might make some improvements.
So, here are the pros and cons of this kit. Pros The kit goes together with almost no problems, and the parts fit together well. The kit lets you build a working printer without needing any extra tools. All I needed was cable ties and a wrench. Setup is relatively straightforward. I barely had to adjust anything to print with PLA. Glass bed with tape already applied. Sturdy packaging.
Cons The X-axis belt tensioning mechanism is poorly designed, making it difficult to attach the belt. The tube for the filament holder was 5 mm shorter than it needed to be. The input capacitors in the power supply have lower-than-specified capacitance.
My opinion: Overall, the kit made a very good impression. Most importantly, the parts fit together, and the process felt more like an engaging activity that gradually got more challenging than a puzzle. I was especially pleased that I could start printing almost immediately after assembly instead of fiddling with settings for a week. You just have to follow one rule: start with PLA filament. It's much easier to learn and work with. Only two things took away from the enjoyment of assembly: an error in the instructions about attaching the belt to the bed (I think they'll fix it), and the awkward way the X-axis belt is attached and adjusted (the mount on the extruder). Not having to flash firmware or spend ages configuring it is a big plus, especially for a beginner who's seeing a 3D printer for the first time. A lengthy initial setup can easily put you off using it altogether. The flash drive came with three test models, but I didn't need them. The bed temperature is a little low, which causes some issues, but that's probably not a flaw specific to this kit; it's more of a general design shortcoming. That's why I didn't list it as a con.
In short, the kit is well packaged, easy to assemble, includes practically everything you need, and lets you start printing almost immediately after assembly.
I really hope this review will be useful, even if not for this particular model, then in general (many printers have a similar design). I'd also love to hear your comments, especially any tips and questions. I'll take some of them into account in the second part of the review, where I'll talk about what I encountered while fine-tuning the printer and test how it works with different filaments.
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