Comparing Entry Level 3D Printers

Dec 5, 2012 : Please note that this post contains out of date information and is in need of revision. May we suggest these other fine links?

The Differences Between ABS and PLA

3D Printer Filament Buyers Guide

These days there are a number of personal 3D Printers to choose from. Personal, hobby, open-source, accessible, desktop, or whatever else you want to call them; they are a new breed of 3D Printers. A 3D Printer you can own and operate in your own home, producing before your eyes anything you can imagine with materials an order of magnitude cheaper than previous commercial 3D Printers.

Below are some statistics and descriptions of currently available or soon to be released personal 3D printers.

Absent are the more varied and technically involved printers of the RepRap branch (though every bit as capable and very much worth checking out).  Also gone are any locked out 3D Printers that limit what you can make or what materials you can use. The companies of these machines control the software and plastic material; charging premiums for their brand of plastic and locking down the software preventing users from adapting profiles to accommodate other plastic grades and materials. Further, while many suppliers of plastic filament clearly state what grades they use and to what tolerances they were extruded, suppliers of these 'closed source' plastics generally make no mention of the grade or precision making THIS 3D Printer operator wary. Until 3D Printer technology sees some massive changes, you won't see the best results from your machine until you feed it plastic specifically extruded for 3D Printing (see our prior post about filament tolerances). That means consistent precise diameter, consistently circular, and of equal density from surface to core. When I buy plastic, I need to know that these have been taken into account. But this article isn't about plastic, it's about printers. It is not to say that any of the aforementioned printers are not capable machines when used as intended, only that they target a different group of users and use a different market philosophy.

I think it is worth clarifying why a couple printers did or did not get included (at least yet) in this post. MakerGear's Prusa for instance. MakerGear has some of the best 3D  Printers and printer components out there and their Prusa is no exception. This post (Which Prints Better) by Rick, the owner of MakerGear was the deciding factor for including the Mosaic and not the Prusa. Check out the article (and the MakerGear Prusa) but to quote the applicable section, "The real difference is that our Prusa Mendel is intended for people who are as interested in building/modding/maintaining the printer as they are in actually printing. The Mosaic is intended for people who are primarily interested in printing." I have great love for the RepRaps and they are well deserving of it; every printer below has its roots from somewhere within the RepRap community. At some point, each of them branched out to appeal to the larger public and this is what they came up with. Even Printrbot, the printed version of which is categorically a RepRap (Replicating Rapid-prototyper), was from the start designed to be sold as a kit easy enough for anyone to build and use. And while proof of that will be in the proverbial pudding, this is the reason it was chosen even though other potentially more capable printers such as MakerGear's Prusa were not. These printers are deliberately targeted to less technically inclined audiences while maintaining enough of a foot-hold in the development community (use of open-source software, electronics, standardized feedstock, etc.) that an owner could expect to see ongoing advances and improvements for their machine. 

Time has gone into distilling the comparable features that will most decide the limits of what you can do with the machine. In this case they are the build envelope, layer resolution, linear speed and the preferred plastic. Together they decide how big of an object can be printed, the smoothness of those objects, how much time it will take to print and what plastic the printer can use. Critiques, suggestions and comments are all very welcome; just bear in mind that these numbers are meant to reflect what an average owner might expect to achieve and be happy with on a daily basis. Doing so without having to dive deep into the theory of what makes the machine go or push the printer beyond its reasonable limits such as to risk other printing troubles cropping up. As time allows and updated information arrives I will add to and maintain this post to keep it current. Additionally, if there are other important metrics you think should be included (customer service, cable management, component quality, etc.) please send them to content AT protoparadigm DOT com! If there is interest we may also put up a poll allowing owners of these machines to rate various aspects of them.

Stats

Printer	Build Envelope L,W,H	Layer Resolution	Linear Speed	Preferred Plastic	Price (Nearest $10)
Mosaic	127, 127, 127 mm (2L)	150 microns	150 mm/s	PLA 1.75mm	$900
Thing-O-Matic	96, 108, 115 mm (1.2L)	250 microns	35 mm/s	ABS 1.75mm	$1,300
Ultimaker	210, 210, 220 mm (9.7L)	40 microns	300 mm/s	PLA 3mm	$1,570
Replicator	225, 145, 150 mm (4.9L)	200 microns	40 mm/s	ABS 1.75mm	$1,750
Printrbot	127, 127, 127 mm (2L)	300 microns	25 mm/s	ABS 3mm	$500
Printrbot+	203, 203, 203 mm (8.4L)	300 microns	20 mm/s	ABS 3mm	$650

Build Envelope

The Build Envelope of a printer is maximum possible size of an object made by the printer. It is often one of the first things a person wants to know about a printer and in many ways directly decides what you can make. It's no fun dreaming about the iphone cover you designed only to discover you don't have the build space to actually print it. Of course printing small objects is better than printing no objects, and you generally pay a higher price tag for the extra build space. When making that decision it is important to consider that twice the length on each dimension equates to 8 times the build volume (2 x 2 x 2), and that while many objects can be printed on the smallest printer, the convenience and options allowed by a bigger build space are substantial.

Box Comparison of Build Envelope

Layer Resolution

The height of each layer is the major factor determining how smooth objects look and feel. In general the thinner the layer, the smoother the sides of printed objects will appear. There are several limiting factors to how thin you can print and in practice they often come down to the intelligence of the code generation engine, the precision of the extruder and the linear speed of the printer. At low layer heights it becomes critical that the extruder is able to smoothly and precisely dispense smaller and smaller amounts of plastic. The slower the print head can travel the smaller that amount of plastic per second is, and if that is combined with an extruder unable to slowly extrude a measured amount of plastic hitting low layers will be very difficult.

If a printer is calibrated very well, steep angles and completely flat surfaces, such as the sides and top of a cube, can have comparable surface finishes at low AND high resolutions. Slopes and curves are where the two start to stand out. As the sides of printed objects slope farther from vertical, printed objects with thicker layers will look more and more blocky.

To demonstrate smooth vertical walls even with thick layer heights there are these beams of plastic T-Slot. The beams below were made with a VERY carefully tuned profile on a Makerbot Thing-O-Matic and the surface finish along the beam is incredible. It is enviously smooth despite being printed at a rather blocky layer height of 300 microns (0.3mm.) I will say that it was an uphill battle attaining these results; the temperature control scheme (PID) had to be adjusted, the manner in which filament fed to the printer was carefully controlled, ambient temperature and humidity was accounted for and many hours were spent fine tuning tool-paths and flow-rates. In the end the carefully crafted profile only gave these results for this specific beam. So while it is possible to attain very smooth side and top surfaces at low resolutions, many never see such results.

This Dragon was also printed on a Thing-O-Matic with slightly thicker layers of 400 microns (0.4mm) and has a distinct 'layered' feel to it.

This bust of Sappho's Head was printed on an Ultimaker at 60 microns (0.06mm) and all but the most gradual slopes appear completely smooth.

Most people will have several print settings at various layer heights. Printing with thicker layers can dramatically reduce the time it takes to print an object and can also increase overall strength. It is not uncommon to have a low detail but fast profile, an every day use profile, and then a high detail, high resolution profile. The software and settings used play a large part; Ultimaker wins out with a 40 micron layer height mainly because using the included settings with netfabb (an optional software package for generating the printing instructions) really does make it as simple as loading up a model to be printed, selecting 'Ultra Quality' (40 micron) and hitting 'Calculate Toolpath.'

Linear Speed

The speed of the nozzle moving in the X/Y Plane (otherwise known as feed/travel rate) will if nothing else make you FEEL like things are printing fast or slow. The actual time it takes to finish an object is a function of object size, layer thickness, linear speed, and object density. But for a given object size, tool-path and resolution, the faster you are able to move your extruder, the quicker your objects will be finished. Going too fast can lead to poor print quality and ultimately failed prints that need to be scrapped. So while it may be physically possible to go quicker than is stated above, doing so may provide inconsistent results and introduce undesirable artifacts.

Recently, acceleration has become a part of the equation and is allowing printers to attain much higher speeds than were possible before. It does mean however, that a printer is not always moving at top speed. For instance, it takes approximately 10mm for the Ultimaker to reach a speed of 300 mm/s and then another 10mm to slow down and stop. Any time the Ultimaker must make a sudden start/stop in a distance of less than 20mm it will not actually reach the target speed of 300 mm/s. As it is often preferable to print at lower speeds during printing moves while only attempting maximum speeds when jumping to a new place to print, the ability to quickly reach the target speed can become crucial for achieving a desirable printing quality.

Preferred Plastic

Most of the 3D Printing community uses either ABS or PLA in either 3mm or 1.75mm diameters.

 

As you can see, natural uncolored ABS has a soft milky appearance to it, while natural PLA is for the most part transparent. They both can be found in various colors and are relatively similar in price per pound. There are a few pointed differences as far as 3D Printing is concerned. Some of those are:

ABS -

• Requires a heated print bed for proper adhesion
• Prone to warping and cracking
• Extrudes around 220 Celsius
• Can emit smelly fumes
• More flexible than PLA
• Petroleum based
• Pieces can be solvent welded with Acetone / MEK

PLA -

• No heated bed requirements
• Minimal warping
• Extrudes between 180-230 Celsius (dependent on volume extruded per second)
• No smell or 'sweet' smell
• More rigid than ABS
• Corn, sugar-cain or sugar-beet based
• More glassy finish when compared to ABS
• Pieces not weldable with readily available chemicals

Up until recently 3mm was the diameter of choice though there is a recent trend towards 1.75mm. In general 1.75mm has allowed for more resolution (glaring contradiction being the Ultimaker using 3mm) and smoother operation. The caveat for 1.75mm is that the tolerances of 1.75mm plastic filament are proportionately not as good when compared to 3mm meaning that it's possible some will notice better results with 3mm, though the finer control gained from 1.75mm may negate this. Again, see our post on filament tolerances and their effects on 3D Printing. Also, while some plastic is offered as a spool-less coil, users of 1.75mm will find any packaging other than spooled to be nearly impossible to manage (unless immediately transferring coils onto spools).

Printers

Mosaic

Seller Website : Makergear

Cost : $899 Kit, $1,299 Fully Assembled

Resources : Makergear Google Group, IRC (FreeNode channel makergearv2)

Pros : Light, stable, portable, fast and easy build, very low maintenance

Cons : Small build space, poor cable management, z-axis precision

More : The Mosaic is a great little printer.  Even though it has a small build space, it has a fantastic size to build space ratio.  It is a fast, easy build, with the hard parts preassembled.  We've used the printer quite a bit and haven't had to re-level the bed once since we leveled it the first time during assembly.  Operation has been very trouble-free and consistent.  The linear rails for the X and Y axes are very simple to set up, and provide smooth, consistent motion without worry of misalignment.  We do wish the pitch on the Z axis leadscrew weren't quite as steep; this would probably make it easier to do finer Z axis resolutions.  We have a few more notes on the Mosaic and a time-lapse of the build available here.

Thingomatic

Seller Website : Makerbot Industries

Cost : $1,299 Kit (Legacy item no longer in stock)

Resources : Makerbot Google Group, Makerbot Wiki

Pros : Frequent upgrades available, large community support, integrated SD Card for computer-less printing

Cons : Reliable printing required frequent maintenance/upgrades, small build space to machine size ratio, poor cable management, requires extremely smooth filament feeding for proper printing

More : When properly built (a full weekend project if new to the scene) and fitted with Makerbot's latest extruder, the MK7, the Thing-O-Matic can be a reliable 3D Printer with a large and helpful community. Though initially billed as a "...high-production factory that sits on your desktop," many users (and Makerbot eventually) abandoned the advertised "conveyor belt" build platform due to unreliable performance. The Thing-O-Matic is capable of producing clean and dimensionally correct prints though some first time 3D Printer owners reported less than optimal results as the printer exhibited a couple quirks that if not accounted for would produce less than favorable prints. Swelling of the wood frame during humidity changes could cause the printer to lose it's reference of the print bed requiring a quick calibration. Or if a stock machine encountered any resistance while pulling in filament, it would cause the cantilevered platform to lift up slightly creating waves in the vertical walls of printed objects. Problems not impossible to account for and fix, but enough to cause head-ache for those who didn't know what they were looking for. It's important to mention that Makerbot has a very large and helpful user-base with many knowledgable people who are eager to help those encountering difficulties.

Ultimaker

Seller Website : Ultimaking LTD

Cost : 1,194 Euro / $1,571 Kit  (exchange rate as of Feb 18)

Resources : Ultimaker Wiki, Ultimaker Google Group, Ultimaker Forum

Pros : Incredibly fast, high resolution, large build space to machine size ratio, many user safety considerations, commercial software option (netfabb)

Cons : "Stringing," bed leveling, z-axis zeroing

More : Currently shipping from Europe (Multi-National Distributors may be pending) the Ultimaker has made headlines for its record breaking speeds and incredibly high resolutions. The speeds at which the Ultimaker prints at require the use of a fan directing air at the nozzle to help cool the objects being printed from turning into a hot slump of plastic. A noted side effect to this is that sharp corners and edges have the highest detail I have seen from a stock machine. There are printable fan attachments for the other printers mentioned here but it is worth noting that the Ultimaker is the only one to include this as a stock feature. It has a very large build space and an optional software package (Netfabb) simplifying the process of printing at high speeds and high resolutions. For many the largest concern is that of "Stringing," where small threads of plastic are trailed into undesirable areas due to the difficulty in quickly removing the force pushing the filament out of the nozzle during a jump. Removing these threads is not impossible but does add an extra step in the process. It is expected that this problem will be mostly, if not completely eliminated with the release of updated software. Also of concern for the user is an instability in the print bed that can require a bit of manual adjustment during the start of a print to ensure a level bed, and the need for frequent (weekly depending on environment, use, and printing speeds) oiling of the smooth rods. We have a few more notes on the Ultimaker and a time-lapse of the build available here.

Printers - Soon to be Released

And so we come to those printers that have not yet stood trial within the printing community. They are presented in the same manner as currently available machines with the understanding that anything said below is based on observations of design, video demonstrations and any other available resources. We have logged many hundreds of hours on each of the previous machines and plan to do the same with these. So when these new 3D Printers are out and in the wild and people start reporting back their experiences, we will update this page with more accurate information.

Replicator

Seller Website : Makerbot Industries

Cost : $1,749 Assembled, ($1,999 Dual Extrusion option)

Resources : Makerbot Google Group, Makerbot Wiki (will undoubtedly soon have resources for the Replicator)

Pros : Integrated LCD, integrated SD Card for computer-less printing, Dual Extrusion option

Cons : Currently most expensive printer in class, unreleased product means unknown problems may arise

More : The Replicator is Makerbot's first printer to come only as a preassembled machine. It has a bigger build space than its predecessor the Thing-O-Matic and an option for dual extrusion (additional $250) allowing for multi-color objects. Judging by it's construction it is possible to say objects printed on the machine will likely be straight on the vertical axis (a problem both the Thing-O-Matic and Cupcake CNC possessed), print at the advertised 40mm/s, but not much faster, and have resolutions between 0.3mm and 0.2mm. 1.75mm ABS is the standard plastic, though with proper profiles the machine will most likely do well with 1.75mm PLA. Of concern to the end user will be how well the printer maintains the level of it's bed during object removal and the nozzle height above bed during humidity changes. I would venture to say that the printer will perform as advertised without tremendous room for improvement or upgrade. It sports an LCD interface that when combined with support for an SD card will reduce the need for a dedicated computer to handle printing tasks.  The Replicator is one the only printer reviewed here shipping stock with an option for two extruders, which may eventually lead to reliable water soluble support structures.

Printrbot

Seller Website : Printrbot.com

Cost : $499 Kit (Kickstarter Price)

Resources : Unofficial Printrbot Forum, Unofficial Printrbot Wiki

Pros : Inexpensive, high build volume to machine size ratio

Cons : Slow, low resolution, unreleased product means unknown problems may arise

More : Currently unavailable to all but those who pledged to the kickstarter campaign. The Printrbot is a low-cost 3D Printer with both lasercut and printed part versions. The printer is the epitome of minimalistic design, as such one can probably expect numerous upgrades and add-ons. Being so minimalistic, there is the concern of print quality and frame stability. For example, threaded rod for vertical movement is cheaper when compared to lead screws, but can have measurable effects on performance (play, backlash, etc.). And while the minimal frame makes a visually open design, many worry that wobble caused by insufficient support will lead to extremely low speeds and/or poor print quality. It is entirely likely however, that after-market solutions or printable upgrades will be released to help alleviate this potential downside. One must also note that the hot-end of the extruder reaches temperatures of 225 Celsius (437 Fahrenheit) and being completely unprotected or concealed could cause sever burns to unknowing or careless hands. (This concern was based on the prototype, after having received our Printrbot PLUS, we see that the production model follows industry conventions for hot-end safety and form-factor.) That being said, this printer hits a rock bottom price of ~$500 allowing many into the printing scene that would other-wise be unable to make the financial hurdle. The Printrbot ships with SD card support freeing your computer up during printing tasks and it's small size makes it undoubtably portable. The native plastic used is 3mm ABS though there is talk of a 1.75mm version. ABS has a tendency to deform, crack or warp when printed in dead open air so it's possible there may be increasing interest in using PLA. At the moment Printrbots are not available for purchase and for awhile the only models in the wild will be self built or kickstarter rewards. There is an imminent opening of a storefront expected at Printrbot.com where printrbots will eventually be available.  Printrbot now has their printers available for sale in their store.

Printrbot Plus

Seller Website : Printrbot.com

Cost : $649 (Kickstarter Price)

Resources : Unofficial Printrbot Forum, Unofficial Printrbot Wiki

Pros : Inexpensive, high build volume to machine size ratio

Cons : Slow, low resolution, unreleased product means unknown problems may arise

More : The big brother of the standard Printrbot, this version has a build volume comparable to the Ultimaker at just under half the price. Like it's little brother it has a large build envelope to machine size ratio and sports a slot for an SD Card. The same concerns exist in regards to part quality, frame stability and safety as for the smaller Printrbot. It is also possible the increased moving mass and volume of the design may lead to further instability. Again, printing large objects in ABS plastic in a completely open frame may present challenges involving warping of the ABS. All said, if this machine works even marginally well it will be an incredible bang for the buck. A slick look, large build envelope at an incredibly tempting price. Many people in the community very much want the Printrbots to be great printers so it is fair to say the Printrbot models will be very closely followed. At the moment Printrbots are not available for purchase and for awhile the only models in the wild will be self built or kickstarter rewards. Again, there is an imminent opening of a storefront expected at Printrbot.com where printrbots will eventually be available. - Printrbot now has their printer available for sale in their store.  We have some notes on the Printrbot PLUS and a time-lapse of the build available here.

Disagree? Tell us...

All of our observations have come from our first hand experience and that of others as described through various blogs, forums and groups. If you feel any of these printers have been over or under evaluated please send an email to content AT protoparadigm DOT com. We love to hear from the community; veterans, newly initiated, and prospective alike.