3D Printer Buying Guide

Just a few years ago, 3D printing objects seemed to be a sci-fi fantasy reserved only for high end prototyping labs. Nowadays, printing everyday objects in the home is a reality that is bringing ever more performance and affordability to the consumer.

Since the 90’s, the 3D printing concept started evolving and picking up speed to finally reach a stage where the public began to be introduced to these machines. With the participation of RepRap and DIY communities, the development of 3D printers for the home quickly evolved to the point where the market is presenting a very large selection of machines to the prospective buyer.

When we think about 3D printing, the first images that come to mind are the almost instantaneous creation of objects with ease. However, the technology isn’t quite yet like the Star Trek replicator where light is transformed into delicious meals and other useful objects. Our goal is to help you distinguish science fiction from reality and make an informed decision.

What do you really know about 3D printing? Are you thinking about purchasing a first 3D printer for the home? Follow our buying guide and learn how to avoid traps and where to look to be entirely satisfied with your purchase!

To 3D print from the comfort of your home you need a machine, but which one is right for you?

First and foremost, you must determine how you plan to use the 3D printer to best maximize your investment. Several parameters must be considered:

• Build volume
• Resolution
• Print speed
• Material compatibility
• Multiple material capabilities
• Control and Connectivity

Build volume is one of the most important consideration when purchasing a 3D printer. It’s also generally directly tied to the pricing of the 3D printer (larger being more expensive). Think about the size of the parts you plan to print and that most 3D printed models are often made of several smaller parts assembled you print them. You may not require the largest build volume out there!

BI Recommends: At least 150 mm X 150 mm X 150 mm of build volume. We feel that anything lower would severely restrict the potential of your 3D printer.

Resolution typically refers to the Z minimal layer thickness and X-Y resolution that can be achieved by the 3D printer. Since motion systems have been around for a very long time, the X-Y resolution is usually quite good for any 3D printer. Since all FDM/FFF 3D printers create parts with a layering effect, the finish quality of printed parts is directly affected by layer thickness resolution. The thinner the layers are on a given part the smoother the part finish will look, but it will also take longer to print. Some 3D printers often report minimum layer thickness as low as 50 micron (0.05 mm). However, printing parts with thin layers requires careful software calibration since the margin for error is reduced. Most users will prefer to print parts with layer thickness of 0.10 mm to 0.30 mm to reduce print time while still retaining an acceptable finish quality.

BI Recommends: 3D printers with 50-100 micron minimum layer thickness.

Print speed represents the speed at which the 3D printer creates parts. This parameter is usually reported in mm/second or mm/minute and usually refers to the fastest speed that can be achieved when the print head is dispensing plastic. Another speed metric representing movement speed (when print head is not dispensing) is usually offered. It’s important to understand that during a 3D print the average print speed will actually be lower than the maximum reported print speed. It is so because the print head has to slow down when changing direction or printing finer details. As a rule of thumb it’s best to use ¾ of the maximal print speed to obtain a more realistic estimation of the print speed (i.e. reported 100 mm/s would yield a true print speed closer to 75 mm/s).

BI Recommends: 3D printers with print speeds of at least 75 mm/second for a feel good experience when printing parts.

Material compatibility is an important factor to consider, because some 3D printers are only tailored for specific materials. More recently, several 3D printer manufacturers chose to only support PLA in order to simplify the print process and their business model. If you have an interest in printing various materials, make sure that the 3D printer you select supports these materials. A parameter to look for is the maximal extrusion temperature or, in other words, how warm the hotend can be heated. Some specialized filament such as flexible filament require specifically designed extruders for best results. If you plan to use the 3D printer for small projects and fun, a PLA only unit is likely to satisfy your needs. For more professional uses, look for a multi-material capable unit.

BI Recommends: 3D printer with a hotend capable of printing up to 250 °C to allow for bot PLA and ABS prints.

Multiple material capabilities allow you to print with multiple colors and materials simultaneously, or to easily switch between various filament options. These options are available on many 3D printers, but typically require a deeper understanding of the printing process to be successfully carried out. Some 3D printers offer robust software that greatly simplify multi-material printing. This will be an area of added value to look for when looking for the right 3D printer.

BI Recommends: Consider your specific needs and ask questions to the manufacturer before purchasing the 3D printer.

Control and Connectivity refers to the software packages included with the 3D printer to control it. Most of the time the 3D printer is controlled via a desktop control software such as Repetier Host and MatterControl. Increasingly, control can be done remotely by means of print servers, mobile apps and Wi-Fi or Bluetooth enabled machines. Most 3D printers will require a physical USB connection from a computer hosting the control and slicing software. A lot of 3D printer also offer control via SD card where the G-code is preloaded and run directly on the 3D printer control board. We favor this control method, because it prevents any problem with the control computer (i.e. going into sleep, crash, anti-virus slowing things down, etc).

One last thing to consider is that simple software/hardware kits such as PrintToPeer can be used to enable Wi-Fi control of any 3D printer through your smartphone, tablet or even outside of the house using any browser. The ability to start, monitor and receive 3D print notifications wirelessly is tremendous so we recommend the latter to everyone.

BI Recommends: Get a 3D printer with a well-established control software and if it does not include the wireless control option make sure to get PrinToPeer.

To launch a 3D print, you typically require an STL file which describes a 3D object with a multidimensional array of triangulated surfaces. The STL is the file that will be “sliced”, a term coined to describe the process by which the G-code (machine instructions) are prepared from a 3D model to be printed.

You can find a multitude of STL files online on websites such as Thingiverse and YouMagine. With the growing number of 3D printer adopters it’s now easier than ever to find free models to populate your “to print” list or inspire your designs.

Besides finding ready to go STL files, you can always design your own 3D models and export them in STL. This method is slightly more complex as you will require CAD knowledge to successfully create your model. There exist several free tools to help you design 3D files. Some of the most popular ones are Sketchup and Tinkercad. More professional users will use paid commercial CAD software ranging from a few hundred dollars to a few thousands (i.e. Solidworks).

Finally, you can also obtain an STL file by scanning an object using a 3D scanner. This technique has been increasingly featured by several 3D printing companies, but some limitations are still present (especially in low end systems). Most 3D scanning systems will feature a turn table, a light source (laser), a camera and the associated software and tools to derive potent STL files from the scans. Some 3D printer designers are also including these scanners into their machines to enable “scanning/printing” dynamics.

Once you have the STL file representing the desired object, you will need to “slice” it using a software tailored to the parameters of your specific 3D printer, the “slicer”.

This is the last step before sending your file to the 3D printer. This is where your STL file is analyzed and converted to X, Y and Z motions along with extruder commands.

The slicing software will take into consideration the geometry of your 3D printer (i.e. Cartesian vs Delta vs Polar, etc.), the speed limitations, the material cooling time and many other factors to generate a very long file of machine instructions that your 3D printer will execute until the part is complete. A large majority of 3D printers on the market operate on the open-loop concept where no positional feedback is provided to the motion controller. The G-code is thus analogous to a “record” being played by the “record player – motion controller”, the “music” being the part information. If a perturbation is introduced, most printers will not recover and continue playing the “music – G-code” until it is finished.

Most 3D printers on the market will come with a software dedicated for slicing. The latter is configured to take into account the particularities of the hardware to optimize the output quality.

Several software companies specialize in the slicing process and there is an active online community discussing the merits, optimal configurations of each options. Some of the most popular slicing engines that are not proprietary include Slic3r and Cura.

The slicing engine is usually included within the 3D printer control software and allows the user to control slicing options seamlessly behind a graphical user interface.

Once your G-code is ready you need to make sure that your 3D printer is calibrated, ready and loaded with the appropriate 3D printer filament (PLA, ABS, or specialized filaments).

Choose the color you want! In most cases 3D printers utilize 1Kg rolls of filament that are available in various colors and material types.

Let’s a make a quick analogy – When talking about 2D printers, the capacity of an ink cartridge is typically reported in number of pages. For the 3D printer, you’ll need to think about it in terms of weight of the object to be printed. Most control software feature G-code analyzing algorithms that can help you estimate the weight of an object before printing it.

The quantity of plastic required per part also depends on the desired “infill” of the part (how much plastic will fill the hidden voids of the part. Typical parts will have between 10 and 20% of infill plastic, but parts where added rigidity and strength are required may go much higher.

The best technique is to print a copy of the desired part, weight it and divide the weight of filament on your roll by it.

3D printing for the home is something that a lot of people are considering, but with an ever increasing selection surrounded by deceiving marketing it can be hard to know what to look for. Our intent is to provide you with the relevant information so that you can be better equipped when you decide to purchase your first 3D printer.

As such, this 3D printer buying guide was designed to provide a quick read of the most relevant points to consider when thinking about purchasing your first 3D printer.

Please contact us if you find any discrepancies or if you would like to see more information added to this article.