As far as 3D printers go, I have yet to see one smaller than the Micro 3D Printer by M3D ($449). This consumer-oriented, budget-priced model is certainly a head turner, inspiring many comments from colleagues about its small size. It has a simple yet handsome design and is unusually (and blessedly) quiet in operation. The Micro is designed for ease of use, with an automatically calibrated print bed. Unfortunately, it was slow in printing in my tests, and the quality of its output is mediocre.

Design and Features
The Micro comes in two versions: Retail, which is what I reviewed, and Standard ($349). The Retail version includes a filament spool and written instructions, and it has a one-year warranty. The Standard model has a 3-month warranty, and it doesn't come with filament or written instructions (although the latter are available on M3D's site). My test unit is blue; other color options include black, white, green, orange, and (for $25 extra) clear.

An open-frame cube with rounded corners, the Micro measures 7.3 inches on each side. It weighs a mere 2.2 pounds, and is easily the lightest 3D printer I've tested. The build area is peculiarly shaped, sort of like a square layer cake. It measures 4.6 inches high and tapers from 4.4 by 4.3 inches (WD) at the base to 3.6 by 3.3 inches at its top. In comparison, the MakerBot Replicator Mini's build area is 4.9 by 3.9 by 3.9 inches (HWD), and the Ultimaker 2 Go's is 4.5 by 4.7 by 4.7 inches. At 6 by 6 by 6.2 inches, the XYZPrinting da Vinci Jr. 1.0 has a slightly larger build area than the Micro, as does the LulzBot Mini 3D Printer at 5.9 by 5.9 by 5.9 inches. The Micro falls well short of the LulzBot Mini, PCMag's Editors' Choice midrange 3D printer. (We haven't yet found a budget 3D printer top pick.) The LulzBot is easy to set up and use and worked flawlessly in testing, but its list price is $900 more expensive than the Micro's.

You can automatically calibrate the removable, unheated print bed via the printer's software. This is one of several 3D printers I've looked at lately whose print beds require little or no manual calibration. Others include the LulzBot Mini 3D Printer, the XYZPrinting da Vinci Jr. 1.0, and the MakerBot Mini. Objects printed with polylactic acid (PLA) filament adhere well to the Micro's print bed, but are easily removable once the print job is done.

Setup
Setting up the Micro is a fairly simple process, thanks in part to the included instructions. When you take the printer out of the box, you have to remove all the bubble wrap, foam, and tape. The instructions emphasize taking off the gantry clips that hold the extruder carriage in place during shipping. One thing that's easy to overlook, however, is a piece of black foam beneath the extruder. Until I found and removed it, I kept receiving an error message saying that the gantry clips were still in place, though I had removed them.

After removing all the packing material, you download the printer's software from M3D's site and install it on your PC. Then you plug the printer in (there's no Power switch, but the M3D logo lights up when the printer is plugged in), and connect it to your computer via the included USB cable. Printing over a USB cable is the Micro's only connection method, unlike the MakerBot Replicator Desktop 3D Printer, which can print over a USB, Ethernet, or Wi-Fi connection.

Filament Issues
The next step is to load the filament, which can be done either internally (a small, proprietary filament spool fits in a compartment at the base of the printer under the print bed) or externally (a spool of any 1.75mm filament can be placed in an optional spool holder outside of the printer, and the filament fed to the printer through a hole in the top of the case). To start loading, you click on the 3D Ink tab in the software. The process varies depending on whether you load the filament externally or internally. Either way, you have to enter a code (based on the filament type) and, when prompted, feed the filament from the spool to the extruder, which grips it with gears and pulls it in. A strand of molten plastic should soon start extruding.

M3D sells half-pound spools of PLA filament, which it calls 3D Ink, for $14 each. It also offers color-changing PLA, which it calls Chameleon 3D Ink, for $18 to $23 per spool. This is slightly less than the $18 of MakerBot's half-pound PLA spools. I used a half-pound spool of M3D's clear PLA filament for most of my testing. M3D also sells acrylonitrile butadiene acrylate (ABS) filament for $14 per spool. The company does not recommend ABS (which it dubs Expert 3D Ink) for new users because it says ABS is challenging even for many larger models to print with successfully and can have a strong odor.

Using an internal spool is convenient and more aesthetically pleasing, with the filament and spool out of sight, but it can be problematic should you need to remove the filament before the spool is used up. To unload the filament, you click on the 3D Ink tab in the software, and click Unload Filament. The extruder's heating chamber then heats up, softening the filament, and you receive a prompt to pull it free. After a couple of minutes, you get a message asking if the filament has been unloaded. If not, the extruder heats up again, and you repeat the process as many times as is necessary to release the filament.

Loading the spool internally in testing wasn't difficult, but uninstalling it was an exercise in frustration. When I had to unload the filament from a spool stored in the printer, I followed the steps above. Despite heating and reheating the filament several times, it would not come free of the extruder. Instead, the thin, plastic tube that surrounds the filament started pulling out of the printer. I reached out to M3D, and its rep came by PCMag's offices. He was able to release the filament, after several rounds of heating, by giving it a series of short, sharp tugs. He took that printer and left me with a replacement unit. I tried unloading the filament the same way he had. After several rounds of heating, it was still stuck. It only came free when I grabbed the end of the filament with a pair of needle-nose pliers after a round of heating and yanked it out.

I tried loaded the filament externally, using another spool set in a holder. With the external method, you don't have to snake the filament through any tubes; instead you just insert it into a hole on top of the extruder assembly. I experienced none of the unloading troubles I had with the internal spool. I recommend sticking to externally loaded filament, which can also save you money, as you don't have to use M3D's proprietary spools for that method.

Software
The Micro's 3D printing software is among the simplest I've used. At the top of the main screen are three icons: the aforementioned filament spool labeled 3D Ink; a file folder labeled Open Model; and a gear icon, from which you can calibrate the print bed.

If you have previously loaded any 3D models with the Micro, you will see thumbnails of them below the icons. You can click on a thumbnail to load the model, or choose Open Model and navigate your file directories to select a 3D file to load. Once loaded, the object will appear on screen within a representation of the printer. You can rescale, rotate, or reposition the object with the aid of several buttons at the left edge of the screen, or center the object with a button at the bottom of the screen.

When the object is scaled and positioned to your satisfaction, you then press the Print button. This opens a dialog box that identifies the printer and the filament. It also lets you choose one of five print-quality settings, with resolutions ranging from 350 microns at Ultra Low to 50 microns at Expert from a pull-down menu. The higher the resolution, the longer the print time is for a given object. A second pull-down menu lets you choose among six settings for fill density (the thickness of infill, the material extruded within the print's interior): two hollow settings, with the walls of different thicknesses, and four settings with increasing percentages of infill. The thicker the infill, the longer it takes to print an object. Below these selections are checkboxes for more options, such as adding supports or a raft (a flat surface made of layers of plastic at the object's base, which can be removed after printing).

Printing
I printed about eight test objects with the Micro. Most were at low or medium resolution, and one was at high. Print quality was fair in my tests; I didn't see much of a difference in quality among the three resolutions. The test prints tended to look slightly rough-hewn, and some fine detail was lost. A couple of the objects showed a fine porousness in spots, which can be eliminated by switching the fill density setting from hollow to low infill. This quality is similar to what I saw with the XYZPrinting da Vinci Jr, another good entry-level consumer 3D printer. However, the Micro had two misprints in my testing, while the da Vinci Jr. completed all the prints it started with no operational issues.

After printing five objects without incident with the Micro, it stopped extruding plastic in the middle of the sixth print job, though the extruder continued to move in its programmed pattern. I aborted the print and tried to launch a new job, but the printer wouldn't extrude. This turned out to be an apparent filament jam, which led me to try (unsuccessfully) to unload the filament, as described earlier in this review. My other misprint happened when the print bed became uncalibrated. After I ran the calibration routine, the Micro was able to print correctly again.

One big downside to the Micro is that it's slow, even at its low-quality setting. It took about 5 hours to print an object the MakerBot Mini printed in only 2 hours, with both printers at default settings. On the other hand, the Micro is the quietest 3D printer I've tested so far, which is a relief for those of my coworkers who sit close to my testing area. Many of the other 3D printers I've reviewed have been loud enough during operation to be a bother.

Conclusion
The Micro 3D Printer by M3D is a tiny, cute, and quiet entry-level 3D printer that sells for a modest price. On the other hand, its print quality proved mediocre in testing, it has a very small print bed, and it's notably slow. The Micro wasn't as fast or dependable in testing as the XYZPrinting da Vinci Jr., another budget, consumer-oriented system. That said, the Micro's frame is unusually compact and lightweight, and its simple, yet attractive design makes it a good conversation piece. Though the Micro isn't the breakout consumer model I've been waiting for, it's worth taking a look if you're on the hunt for a solid starter 3D printer.