The short answer: something like $200, if your time is worth $0/hour. How is this possible? Cheap kit printers, with laser-cut acrylic frames, but otherwise reasonably solid components. In particular, for this review, an Anet A8. If you’re willing to add a little sweat equity and fix up some of the bugs, an A8 can be turned into a good 3D printer on a shoestring budget.

That said, the A8 is a printer kit, not a printer. You’re going to be responsible for assembly of every last M3 screw, and there are many. Building the thing took me eight or ten hours over three evenings. It’s not rocket surgery, though. There are very accessible videos available online, and a community of people dedicated to turning this box of parts into a great machine. You can do it if you want to.

This article is half how-to guide and half review, and while the fun of a how-to is in the details, the review part is easy enough to sum up: if you want the experience of building a 3D printer, and don’t mind tweaking to get things just right, you should absolutely look into the A8. If you want a backup printer that can print well enough right after assembly, the A8 is a good deal as well; most of the work I’ve put into mine is in chasing perfection. But there are a couple reasons that I’d hesitate to recommend it to a rank beginner, and one of them is fire.

Still, I’ve put 1,615 m (1.0035 miles) of filament through my A8 over 330 hours of run-time spread across the last three months — it’s been actively running for 15% of its lifetime! Some parts have broken, and some have “needed” improving, but basically, it’s been a very functional machine with only three or four hours of unintentional downtime. My expectations going in were naturally fairly low, but the A8 has turned out to be not just a workhorse but also a decent performer, with a little TLC. In short, it’s a hacker’s printer, and I love it.

$200 and Twelve Hours of Labor

The Anet A8 itself is a kit, and you’re looking at a few nights of assembly before it even resembles a 3D printer. Some of this is educational and fun, but other parts of the build are pure tedium. Just peeling the protective film off of the many, many laser-cut acrylic frame parts took me two and a half hours one evening. And if that doesn’t sound like fun, just wait until you start fiddling the myriad M3 nuts into those cursed acrylic T-shaped bolt slots. Ugh. But you grit your teeth, take your time, and you get through it. Do follow the excellent videos, especially the part near the end on bundling up the wiring harness. It’s worth it.

Now you’ve got a half-decent 3D printer for $150; get ready to spend a little more. I wouldn’t consider the printer complete without a better build surface than the provided masking tape, which will only survive your first couple of prints. Add $15 for some PEI film to your budget. Toss in the price of a kilogram of cheap PLA filament as well, because you’re going to need to calibrate the printer and make parts to improve it before it’s “done”. I got orange on sale at $15.

The A8 is noisy. I replaced the shipped LM8UU bearings with Igus Drylin bushings because the former rattled, so that’s another $10 I sunk into the printer that’s optional but pleasant. And then I bought a 50 cm square cement paving tile from the hardware store for $3 to use as a base. It’s rock solid and the mass helps stabilize the printer and absorb vibration. Putting this on top of a $10 rubber washer/dryer isolation mat keeps it from coupling into the table below. It’s not exactly quiet now either, but we can sleep at night with it running.

In the end, I also needed a Molex connector that I scrapped from an old PC, but you can imagine paying another $5 for the part. I turn the power on and off with a $1 switch from the hardware store. So in even the most complete accounting, the $150 printer cost me $200. That’s still a ridiculous bargain, or at least it will be after some tuning.

Printing Your Way to Nirvana

Once the printer is built and calibrated, the first thing you’re going to want to print is a new nozzle for the print-cooling fan. The one that’s included blows on the hot end and cools it down, making temperature regulation spotty. Worse, it doesn’t direct the air well enough to the print either. For PLA, which requires heavy cooling on small parts, this is a killer. I’m running the Mistral because it looks cool, but the half-circle nozzle seems just as effective. This is your first print, after perhaps a calibration cube. You could stop here if you wanted, and enjoy prints that are as good as the status quo of about five years ago. That was easy.

Celebrate a victory lap by printing a filament guide and/or a button for the horrible bolt head that will eventually tunnel into your thumb when swapping out different filaments. (More on this later.) These are quick and easy improvements to both print quality and your quality of life.

The next biggest complaint with the A8, from nearly everyone who owns one, is the frame. While billed as a “Prusa i3” clone, it’s a little bit like selling a Ford Pinto as a Lamborghini Countach clone — after all, it uses a similar steering wheel and four tires. If you owned a RepRap Mendel or first-gen Printerbot, you’ve probably seen the ringing that a wobbly X-axis causes in a print. Fixing X-axis wobble was one of the main goals of the Mendel 90 and Prusa i3. The A8’s X-axis, in contrast, wiggles like a bowl full of jelly.

Photo by [orincus] of his test objects, demonstrating bad ringing To be fair, the ringing isn’t that bad at low speed anyway

The quick-and-dirty solution for X-axis wobble is to print something like a T-brace to stabilize the top joint of the X-axis frame. The print is very quick and the results are, well, mediocre. Subjectively, I thought that it helped, but when I ran tests for this article, it doesn’t look like it makes all that much difference. Ah well.

Anyway, the Y-axis design is dodgy too. The front acrylic plate flexes when the motor pulls against it, and this leads to a deflection that you can feel with your finger and causes backlash in prints. This symptom got worse and worse over the printer’s life, until just recently my circles became so non-round that I had to fix it.

The good news is that a Y-axis, frame-induced backlash fix is easy. If the first virtue of the A8 is that it’s cheap, the second is that there’s a large community of people working on improving it. [Leo N], in particular, has built both front and rear Y-axis braces that work marvelously, and have been tested by many A8 owners. Measured with an XY backlash test print, my Y-axis backlash went from 0.2 mm to 0.06 mm with the front brace, and down to unmeasurable with the addition of the rear brace. Problem solved.

Front brace prevents flex Back brace couples motor more directly to threaded rods Even bands at the top = bad, at the bottom = good.

[Matsekberg]’s Y-axis re-work also looks very good to me, because it offloads the tension in the Y-axis belt onto two additional threaded rods. It’s a more involved modification, but it might be worth it.

This still leaves acrylic frame wobble and the ripples. The nuclear option is to replace the entire frame. You could simply buy a decent frame kit and use that instead, which for $50-70 may just be the right way to go if you’re starting from scratch. Or you could print your own connectors and build the rest of the frame out of aluminum extrusion. There is an active community around the AM8 design doing just that, for instance. Both of these options involve a complete re-build, which costs you an evening or more. For me, the minor cosmetic flaw hasn’t warranted the effort yet. I’m too busy running the thing.

The Really Bad News

Somewhere around 130 hours of runtime into the printer’s life, the hot end intermittently stopped heating. I had just swapped in a new fan duct, so I thought that maybe it was blowing on the heater or something. But when the heater failed completely, I discovered that the crimp connections on the heater cartridge had come loose. I pulled these out and re-crimped them, and it’s been running fine ever since. But I’m keeping my eyes on them. Check all of the crimps during your build to be sure.

Older versions of the A8 also had a connector on the motherboard that was insufficiently specced for the current it had to carry, and this printer got the deserved reputation as a firestarter. My August 2017 A8 had swapped these out for screw terminals, a welcome change. My heated bed failed after around 150 hours anyway.

The singed plastic was to be found on the heated bed itself. The connector at the joint there is repeatedly wiggled every time the Y-axis travels back and forth, losing contact and arcing hot enough to melt and blacken the plastic shroud. Scary business.

In the end, I simply removed the pins and soldered the wiring from a PC power supply, complete with a pair of Molex connectors, directly to the heated bed. I would do this modification before installation if I were doing it again to prevent eventually rebuilding the Y-axis.

Both of these problems stem from dodgy connections of parts that are heated to various degrees and under repeated flex strain and significant vibration. Here’s an Ask Hackaday: what is the right connector or strain relief solution here?

Filament: Creature Comforts

My last complaint about the A8 is changing filament. The filament path is blocked by a fan and heatsink that keep the top of the hot end cool. Inserting new filament without completely unscrewing these is a pain. Various solutions range from forgoing the heatsink entirely to designing a hinge or basket for it.

I took the middle road and cut down the heatsink to 1/3 of its original size, and printing a shroud and clip system for the fan. I don’t want the fan blowing dust into the filament path, so a shroud was a must, and I didn’t feel comfortable about losing the heatsink or its tight mechanical connection to the top of the heat break.

It’s very easy to change filament now, and the top of the heat break seems to stay cool, even under sustained use. I’m content, but there must be a cleaner solution out there. The filament-changing issue is a creature comfort, and if you don’t switch among filaments often you might not even care, but for me, it was worth experimenting around for a few hours and eventually taking a hacksaw and drill to the heatsink.

The Bottom Line

If you’d like to walk down the A8 path, get ready for a fair amount of work that can eventually be rewarded with proximity to printing Nirvana, if not absolute bliss.

Would I recommend the Anet A8? First, you have to be sure that you want a kit. A lot of labor goes into turning a pile of parts into a working printer, and a bit more goes into making it a good printer. If you think you’d enjoy that kind of hands-on experience, just order one — you won’t be out that much money anyway. I love mine, and it’s proven very reliable in the grand scheme of things, but the gears needed to be adequately greased with my blood, sweat, and tears.

If you want a printer to work beautifully straight out of the box, this is not for you. You’ll be much better off spending $500-$1500, and there are many attractive options these days. In the long-run, you’ll probably still be doing a similar amount of maintenance and tweaking — that’s just the reality of 3D printing — but at least you’ll hit the ground running.

The only serious qualm I have about recommending this printer is the problem with intermittents in the hot end and heated bed. Because it’s potentially a fire hazard, I take this shortcoming reasonably seriously. My printer sits on a 4 cm thick slab of concrete, and I don’t want you burning your house down.

At the price, I’m sure that many of you have at least toyed around with an A8. Post up in the comments with your favorite mods, workarounds, and fixes. What’s the right solution for the hot end and heated bed connectors? Do you have a better solution to the filament loader issue? Good experiences or bad?