Choosing a Printer

There are MANY factors to consider when trying to choose a 3D printer for either personal or professional use. If you’re a teacher who is trying to choose one or several printers for use in your school, then it’s not unlikely that one of your largest concerns might be price. As with anything, though, you often get what you pay for.

Now, you may read this page and say, “Okay, Nathan, this is all well and good, but you still haven’t told me which printer I should buy for at home or at school!” To which my response is, “Well the fact of the matter is that no one can tell you which printer to buy but you. Some people will hate MakerBot and others will love it. Some will swear by PLA as their filament of choice and others will only print with ABS. Before making a purchase like this, I’d strongly advise looking around the internet for the reviews that other people have shared and make a well-informed purchase.”

Here are some places that you could look for reviews and opinions on the best current printers: The 3D Printing Subreddit provides a list of current printers on the market that pass tests determined by the community of the page. This is a public community which is unlikely to be swayed by corporate gain.

The website 3D Hubs offers a great guide for making your big choice as well, including descriptions, pros and cons of current printers, as well as commentary and user reviews of the current top 3D printers. All3DP also provides a top ten printer guide that they update monthly. There are many other such lists available to find. The only tool you need to find them is Google.

Now let’s talk some important factors to consider when making a purchase:

Price: By no means is cost unimportant. As of the time when I’m writing this, 3D printers can range in price from as low as a few hundred dollars to as high as several thousand. Often the price of a printer will reflect many other qualities about it, such as the “newness” of its running design, the brand name, its speed, its ease of use, its software, its precision, and its overall reliability. A printer kit (some assembly required) that sells for $600 could be loud, slow, have poor limits on its layer height and precision, but could be well-designed for beginners who wouldn’t know what to do with the features of a bigger and better printer even if they had access to it. Alternatively, someone who wants a printer for professional use would have limited use for anything that runs under $4000 because they require the level of exactness and speed that that printer may offer to them. So my advice is this: don’t just decide on a printer based off of how much it costs.

prusa-i3-steel-pro

The Prusa Steel is a build-it-yourself printer kit which is sold for about $460 USD

Material Used: One of the biggest considerations to make when deciding on what printer to invest in in what you’re going to use to print with. The two most common plastic filaments used for 3D printing are called ABS (Acrylonitrile Butadiene Styrene) and PLA (polylactic acid). These often come provided on spools that the filament gets pulled off of like thread in a sewing machine.

Check out the next page for more information on choosing your materials.

Ease of Use: This is almost an oxymoron. 3D printers by necessity need to be extremely fine-tuned. There will be times when fractions of a millimetre could mean the success or failure of a given print. If a print bed isn’t leveled perfectly then a print could fail 13 hours into a 14 hour print and there will be many tears shed. (I know this from experience.) Due to the fact that printers are a cutting-edge technology, they are still very much in development and new problems will arise with every new model to be released. All this being said, there are certain things that make some printers more easy to use than others.

Many of the easiest printers to use are the ones that require limited assembly and are ready to go right out of the box. They generally have good customer support, high reliability (check reviews), and low failure rates. Some trade-offs are that because a printer may be pre-assembled, there is little to no room for personalization when it comes to improving or augmenting a machine (for example, you couldn’t add a larger build platform). Some other factors to consider here are features such as self-leveling beds; you’re going to be leveling a build platform once every few prints, otherwise you’re risking disaster. By having in-built software and sensors that do this for you, you’re able to eliminate a lot of time and effort involved when doing this manually.

Build Area: The build area of a printer is defined as the space in which an object can be printed. The name can be misleading since an area is defined as a space within 2 dimensions, but since we’re dealing with 3 dimensions then often it will be referred to as (more appropriately) the build volume. The build volume is often described in terms of length times width time height (LxWxH). Deciding your ideal build space is quite dependent on what you plan on using the printer for. An enthusiast would generally be quite happy with something along the lines of 200 x 200 x 185 mm, but beginner printers can go quite a bit smaller, along the lines of 140 x 100 x 100 mm. Speaking from experience, quite often prints made are going to be on the small side, and if a printer is being used in a school setting then often prints are going to want to be kept quite small for the sake of time and the saving of materials.

lulz5

The LulzBot TAZ 5 is a popular, but more expensive printer that has a very large build area.

Heated Bed: A lack of a heated build platform can easily be a deal-breaker to some buyers. While not necessary, a heated bed can be invaluable to someone who wants to print on a glass sheet or with ABS filament. If I were to recommend purchases of printers for a school, I would probably say that at least one printer purchased should have a heated bed.

Enclosed Build Space: This builds off of the rationale for having a heated bed. When printing with ABS filament, for example, it’s important to keep the build space hot. If the material gets too cool too soon then the print will warp and fail. Once again, this is situational, since I find that when I print with PLA filament it works best when it has lots of air circulation to cool off the filament as quickly as possible.

Print Speed: This one is pretty obvious; it’s the factor that determines how quickly an object will be printed. In some printers, the extruder head will move in the x, y, and z dimensions, while other times it will only move in one or two of them and the bed will move in the others. These movements are driven by motors that move the extruder or the bed and can be limited in their physical capacities. You don’t want to push a motor too far by going to fast because it could break the parts and that could be very problematic to replace or fix.

Print speed also controls an aspect of the quality of a print. In general, the higher the print speed, the lower the quality of the build. In many groups, a print speed of 30 mm/s is considered the average speed for making quality objects, but there are many printers out there that can reach speeds of around 60 or 90 mm/s (for PLA) without significant loss of quality.

For classroom use, I would say that you shouldn’t need more than 60 mm/s as a maximum print speed, but that should be a speed that most printers can reach easily.

form2

The FormLabs Form 2 prints with liquid resin as opposed to filament and can print much faster than filament-using printers

Layer Height: In very broad terms, layer height is going to be one of the most defining factors in the resolution of a print. Basically the way that traditional 3D printers work is that it’s 2D printing over and over and over again. Each time a layer is printed, it’s printed at a certain height. Most prints will be printed between 0.15 mm and 0.20 mm, both of which provide excellent quality. If you go over 0.20 mm then the layers become very obvious, but the lower the layer height gets, the “smoother” it will look. The trade-off, of course, is that with thinner layers, more layers will be needed, and as a result, the time it takes to print an object will go up quite a bit.

For use in schools, a layer height of 0.15 or 0.20 mm is perfectly fine, but most printers on the market should be able to go finer than that.

Connectivity: In general, there are two ways to send files to a printer: One is to load the finished files on an SD card and the other is to print directly from a computer. Printing from a computer can be done either through a cable or over a wireless connection. It’s widely considered that SD cards are the way to go since they use flash memory, and this ends up causing fewer problems than printing directly from a computer does (due to connection issues).

That being said, one of the biggest advantages of printing directly from a computer is that it gives you direct control over the print process immediately. If you notice that a print that’s in progress could do with a little less heat, then adjusting that from a computer is easy, where it’s usually not possible to do this from an SD card. Not needing to worry about lost or stolen SD cards is also a plus.

Software: I’ll go into this more in the next few pages, but for now you should just recognize that not all slicer software is going to be compatible with all printers. Mostly this comes down to incompatibility between types of coding, but there will also be times when printers are designed to only work with one particular slicer program. It’s certainly worth looking into what slicing programs that a printer is compatible with before making a purchase.

Dual Extrusion: Most printers will only have one extruder head; that is to say that they can only print with one colour at a time per print (unless the filament is swapped out partway through). There are printers with options of more than one extruder, which allows for what’s called dual extrusion: printing with two colours or materials in the same print.

2015-06-14 20.02.37

I love my Flashforge Creator Pro, which has dual-extruding capabilities

While this provides for interesting opportunities, it’s by no means necessary, and at times it can even be a hindrance. Leveling a build platform for dual extrusion means that both nozzles need to be perfectly aligned and at the same height. If this isn’t the case then a print could be ruined because the filaments aren’t being laid down at the same height, and could even get knocked over by the lower of the two nozzles.

For a classroom setting, I would say that having more than one extruder on a printer is not a must-have.

Now I understand that this is a lot to take in, but purchase of a several-hundred to thousands of dollars piece of machinery is not something to be taken lightly. You need to determine what factors are must-haves for you, what would be beneficial to the classroom, and what you budget will allow for. If you’re still having trouble, then there are many websites out there that will help you to make this decision, but it’s also helpful to keep in mind that some of these websites may have their own interests at heart (like promoting their own brand), so take this advice with a grain of salt.

 

Like I said above, though: knowledge is power. Don’t let someone else decide what printer you’re going to get. Make an informed decision before you buy.

When deciding on a printer, it’s also important to keep in mind where you’re going to get your materials from!