How to Choose a 3D Printer
By: Shawn Grover
Tags: Technology, Makers, 3D Printing

How to Choose a 3D Printer

For those looking to create at home.

Photo by Xiaole Tao on Unsplash

So you want to get a 3D Printer and make things. We all have to start somewhere and are likely to make errors in judgement along the way. At least until we learn more. Starting with the right printer helps avoid frustrations, delays, and discouragement. Read on if you are starting from scratch.

3D Printing Methods

There are three common ways to “3D Print” an object. The right choice for you depends on how you respond to the factors we mention below. But first we need to define these 3D Printing methods.

Filament Diposition Method / Fused Filament Fabrication (FDM or FFF respectively) pushes a plastic filament through a heated nozzle, much like a hot glue gun. That nozzle is moved to the correct position in an X/Y coordinate system, then moved “up” along the Z axis to apply the next layer on top. These printers are not very costly (in comparison to the other printing methods) and the materials are cheap as well. They are difficult to achieve layer heights smaller than 0.1mm though. It is possible to do so, but these printers take much longer to print at those layer heights. Still 0.1mm or even 0.3mm is more than good enough for a number of objects.

Sterolithography (SLA) uses a liquid resin material instead of spooled filament. Exposing the resin to ultraviolet light hardens it. Selectively choosing where that light is applied results in a hardened layer. The build plate is then moved to the next layer and the light is applied again. Layers can be applied faster and are often 50 microns or smaller. So an object can be printed with a much smoother finish faster. The negatives here are that you are working with a liquid resin that will need to be cleaned off the part afterwards, and that resin needs to be “cured” to harden the material fully. Resin printers can be acquired for a similar price as the FDM/FFF printers, however the resin is more expensive than a spool of filament.

Selective Laser Sintering (SLS) uses a powdered material placed down in very thin layers. A laser is then used to melt or harden that powder where needed. Then the next layer of powder is applied. The part may need to be “baked” afterwards to remove the plastic binding material and leave only the metal or ceramic behind. This process can achieve very fine layer heights and the powder material can cover a wider range of materials (plastic, ceramic, rubber, metal, etc). SLS devices are not cheap nor small. You do not hear about desktop SLS printers like you do with Resin or FDM/FFF printers. These devices are normally found in industrial applications like automotive factories.

Chances are that an SLS printer is not well suited for you when getting started with 3D Printing at home. So we will not mention SLS again.

Purchasing Factors

There are a few different factors that come into play when you buy a 3D Printer:

Intent

Time

Maintenance

Price / Ongoing costs

Post Processing

Intent

If you are intending on doing LARGE objects, or objects that do not need micrometer scale layers (resulting in smoother surfaces). Then an FDM/FFF printer is probably better suited to you. These printers routinely have print areas measuring 220mm X 220mm X 200+mm (X/Y/Z). Smaller or larger print areas can be found, with a corresponding shift in price.

If you are intending on designing jewellery such as rings, earrings, necklaces, broaches, etc. then a really smooth finish is needed. And the objects to be printed are relatively small. This favours an SLA or resin based printer.

Time

Are you more interested in the end result — the actual 3D Printed part — but couldn’t care about the details of how it is generated? Or do you want to know everything, diving in so you understand what every nut and bolt does and why it is where it is? Using a bad car analogy — do you just drive the car or are you a mechanic who loves to work on the car?

How you answer that indicates where you would like to be spending your time. If you just want to use the 3D Printer and arrive at the final product, then you want a printer that is “out of the box” ready (or as close as possible to it) and needs as little maintenance as possible. If instead you love to know how things work and enjoy taking things apart, then a “kit” printer is probably right for you. Kits are cheaper and can be quickly assembled.

An out of the box ready printer is going to cost more, even more for a good quality printer with low maintenance needs. You can expect close to $1000 or more for this type of FDM/FFF printer. SLA printers have fewer moving parts and are closer to the out of the box concept by default. (Note that this is a generalization — there are many models out there and some easily counter my statements here. These are outliers though, IMO.)

Maintenance

Still on the time topic, we need to touch onto maintenance. 3D Printers require constant maintenance. The print bed must be cleaned between prints or failures are more likely. The moving parts need to be oiled/greased once in a while. Nozzles have to be replaced. LCD screens will need to be replaced. This maintenance applies to ALL printers, whether they are out of the box ready or not.

This is where buying a kit printer is helpful. By building the kit you learn the ins and outs of how to maintain your printer. Buying an out of the box ready printer simply means you can get a few prints done before you have to learn the same lessons.

In my opinion, maintaining an SLA printer takes less effort. Only the Z axis moves. Everything else would either be a wear and tear item (i.e. just replace the item when it finally fails), or a routine task that has to be done for every print anyway. FDM/FFF printers have those routine tasks too — such as levelling the print bed. However there are more moving parts which means more possible points of failure/maintenance.

3D Printing is not as fast as the Star Trek Replicator devices. It takes time to build a 3D object. Smaller objects can be created in 15 minutes or so, but larger objects can take many hours, or even days to print. Some printers are faster than others. That speed though is a result of the individual 3D Printer design and how the printer is tuned. Tuning a printer is part of the maintenance time.

Price / Ongoing costs

You can find 3D Printers for under $100. Most of those are gimmicks or have very small build surfaces and other limitations. Occasionally a gem is found though in that price range, so it is worth doing the research on the cheaper printers. Keep in mind though that with cheap you get what you pay for. That printer may need a lot of extras or add-ons to make it reliable or high enough quality. At which point it might be better to spend more on a better printer in the first place.

At the moment a good starting printer can be found for around $300. These would be kits that need to be assembled. Out of the box ready printers begin at around $800, but are routinely seen in the $2000 — $5000 range.

One kilogram of plastic filament sells for $20 — $200, depending on the filament type and vendor. PLA/PLA+ is a good general use plastic which is at the bottom end of that price scale (and recommended for starting out with). ABS or PETG would be a better choice for high temperature applications (like sitting in the sun, or in a car in the sun) and sell for $35 and up for a kilogram.

Resin is a little more expensive than filament. Planning on $50 for a 500 gram bottle would be a good starting point.

Ongoing costs include the price of replacement parts, tools, and other routine items like grease/oil. Once you have tooled up though the ongoing costs tend to be focused on your printing material.

It might be considered a good practice to have a collection of replacement parts for just about everything the printer needs. A spare extruder, control board, power supply display screen, wires, rods, etc. If any of these items need to be replaced your printer is most likely unusable until the replacement arrives. Having that replacement on hand reduces your down time. This is not “required”, but commonly recommended.

Post Processing

You have a working printer, you know how to maintain it, and you can print out parts. WHOOHOO! That is quite the accomplishment.

Just one last thing to consider. How much effort is needed to “finish” the printed part?

With FDM/FFF printing, this may include removing support material, cutting off the occasional errant string of plastic, assembling many parts into a single completed object, or sanding and painting. Often though the part can be simply removed from the print bed and used.

With SLA getting the part printed is only the first half of getting to the final object. After printing the excess resin has to be removed and then the part has to “cure” to the correct hardness. Only then can any additional steps be done (like assembly, or sanding and painting) and the part be considered done.

There is a trade off then between SLA and FDM/FFF printing techniques. While SLA may print better quality parts in less time, it cannot do as large an object and the part cannot be used directly off the build plate. Still there is a place for both approaches. Matching the right approach to your own needs is what is key.

Wrapping Up

That is a lot of info to take in. But we all have to start somewhere. With this you should now be armed to begin making a more informed decision as you look at the different printer models out there.

I am tempted to recommend some specific printers to get started with. However I believe the information above will be applicable for some time, while a “recommended printer” will only be good for a month or two. There are new models coming out on a regular basis and the technology keeps improving. So I’ll avoid making a specific model recommendation.

BUT I can recommend some vendors. (I have no affiliations with any of these vendors. I am just reporting what I have learned through my experience and research.)

Prusa Research built the 3D Printer that all the clones emulate. The Prusa I3 is a well known design that continues to evolve. Prusa Research is respected very well in the industry and sells printers, printer parts, and filament.

Creality is a well known vendor who is making good printers. The printers have good support in the various software tools out there.

Let me know if I missed any vendor that should be in this list.

Watch for future articles from me on 3D Printing topics. We have only just scratched the surface here.