Getting a 3D Printer – Part 2: Choosing a Printer

At this point there are quite a few designs/products/kits available, both open source and proprietary, and they are in more or less the same price range (~$500-$2000).

There are quite a few things to consider.

Open Source vs Proprietary

In the open source category, most designs are from the RepRap project. There are a few very well tested and reliable designs, as well as a few very cool experimental designs for the adventurous.

One example of a well tested design is the Prusa i3, and it’s generally regarded as a good starting point for people with little/no prior experience with 3D printers, and that’s what I eventually went with.

While it is definitely possible to build a RepRap from the ground up just following instructions on the site, I wouldn’t recommend it because it would take ages to source all the parts, etc, and isn’t fun and really doesn’t allow you to learn much.

There are many companies/people that have collected all the parts needed to build a RepRap, and sell everything you need to build a RepRap as a kit. The RepRap site has a list of vendors of such kits, as well as assembled machines.

As for proprietary machines, the most famous ones are probably from MakerBot. From what I read, they seem to be pretty nice, but very expensive machines. With the smallest model starting at $1,375 with no heated bed (severely limiting plastic options, discussed below), and a tiny print volume, I don’t think it’s worth it. You can get a much more capable RepRap for about half that price. Don’t be misled by their layer height specification – all printers can do 0.1mm layer heights, as long as you don’t mind waiting couple days for small prints. It doesn’t mean much.

The Cubify Cube is also interesting, and is what I planned to buy initially, but I eventually decided against it because of the expensive filament cartridge system (most printers allow you to use generic spools, as long as the diameter matches), and apparently sub-optimal software support. And being a closed-source product means there are no alternatives, and you can’t try to fix it yourself.

Solidoodle, from what I heard, has non-existent support, but I didn’t look into it much. They advertise their printers as being destructible… I don’t know how useful is that. I don’t think I’ll be throwing my printer out of the window (and expect it to keep working) any time soon.

Printrbot also looks very nice, especially the new version with heated bed, but it had a couple months lead time when I was looking for a printer, so I didn’t really look into it.

Afinia┬áhas a small print volume, and was priced too high for me, so wasn’t considered.

The open source vs proprietary choice in this case is not only ideological – it has very practical implications, and which one you choose will depend on how you like to work.

At the current state of 3D printers, unfortunately, you will most likely hit a few significant problems before you can get beautiful prints out, and how you can tackle the problems depends on which path you take (open source vs proprietary).

NO printers work out of the box, despite what all the manufacturers say (at least below $3000). People have as many problems with expensive printers with proprietary designs as with those with open source designs.

With open source designs, you can try to fix it yourself, search on forums, try alternative firmwares, etc. This is especially true if you bought the printer as a kit and assembled it yourself – you’ll have a pretty good idea of how everything works, and be able to fix things as they break.

With commercial designs, you’ll be at the mercy of the manufacturer. You can’t usually use alternative software/firmware, and modifying the printer will probably void the warranty. Obviously then, choosing a manufacturer with a good support history is very important. But what if the manufacturer goes out of business next year, and their software is not compatible with Windows 9 (or whatever the next Windows version is at the time you are reading this)?

Ultimately I recommend getting a RepRap kit and assembling it yourself. That way you’ll get a lot of value for the money you are spending, and know the printer inside out and know how to fix it when (not if) it breaks, and don’t have to rely on a company staying in business, and continuing to provide good support. The only downside is 10-20 hours of your time assembling it.

Heated Bed?

A big problem in 3D printing is warping – the part deforming while getting printed due to some parts of the part getting cooled more than other parts while printing, and shrink more than other parts.

A heated bed helps by keeping the part hot throughout the entire print, so it can cool more or less uniformly afterwards (and shrink uniformly).

The 2 most common low end printing materials are PLA and ABS, both thermoplastics. PLA is more brittle, and printed parts deform easily when heated (for example, under the sun). ABS is stronger, can withstand very high temperatures, but is more prone to warping during printing.

Which one you choose is pretty much personal preference, but ABS requires a heated bed to print reliably. PLA benefits from, but does not absolutely require a heated bed.

I’d imagine a heated bed is even more important for higher temperature plastics like Nylon and Polycarbonate that people are now experimenting with because of their unique properties.

Having a heated bed is definitely a big plus.

Enclosure

Some printers have enclosures to further reduce warping by keeping inside air hotter than ambient, and also stops breezes from the outside world from cooling the part getting printed unevenly.

I don’t really know how much they help, but my printer doesn’t have one, and I would like to make an enclosure for it some day.

It’s definitely a plus, so I would get it if it’s not prohibitively expensive, but many people do print a lot of beautiful things on open printers.

Multiple Extruders

Most printers only have 1 extruders, which means only 1 material and 1 colour per part. A dual extruder printer would allow you to print parts with 2 colours for example.

Another cool use of the second extruder is to use it to print a different water-soluble support material, so it can simply be washed away afterwards.

It’s definitely nice to have, but I don’t think I’ve seen it in any <$2500 printer. It also makes bed leveling harder.

Hotend

The hotend is the part of the printer that is responsible for melting the filament, and guiding the melted filament through a thin opening to be deposited on the part being printed.

If you buy a RepRap kit, there will probably be a hotend included, or you may get a few options to choose from.

There are many designs, and the most popular one seems to be the J-Head. The most important thing for a hotend is to be reliable. Jams are incredibly annoying, and sometimes requires replacing the entire hotend (which is not cheap!). Just read reviews online, and see what people say about the hotends you are thinking about getting. In most cases, it’s possible to buy and use hotends from third parties if you so choose. They are all compatible for the most part. Just make sure the voltage for the heating element is the same, and the voltage for the fan is the same (if there is a fan), and the thermistor type is properly set in firmware. If you choose to go down this route, it may be easier to re-use the fan and thermistor from the original hotend.

J-Head is reportedly very reliable and awesome in general, but it is a plastic hotend so it can only be used with ABS and PLA, because at the higher temperatures required to melt other kinds of plastic, the hotend itself will melt.

There are now a few all-metal hotends available that are rated for much higher temperatures, but many of them have problems with filament jamming, so do research carefully if you want to use an all-metal hotend. I’m using E3D, which is one of the all-metal hotends with very good reviews, and I’m very happy with it. I couldn’t find a local reseller, though, and had to order from Europe.

The filament diameter needs to match the filament you are using – either 3mm or 1.75mm. There doesn’t seem to be much difference which one you choose, as long as they match.

A smaller nozzle diameter (diameter of the final opening) allows more detailed prints, but makes printing slower, calibration MUCH harder, and also more jamming. Starting with 0.4mm or above is probably a good idea.

Print Volume

Maximum dimensions of objects that can be printed. Obviously the larger the better, but most printers cannot reliably use the entire area without running into other issues, like warping.

What I Chose

I evaluated about 20 printers, and ended up choosing MakerFarm’s 6″ Prusa i3.

It’s a fairly standard Prusa i3 with heated bed, single extruder, J-head or Magma (all-metal) nozzle, and and LCD with SD card slot.

It does not have an enclosure, and there are a few places that can be improved (will be detailed in the next post), but at $495 it’s absolutely a steal. Most comparable printers cost more than twice as much.

Colin, the president of MakerFarm is also a very nice person to deal with. I sent him a few questions before purchase and during assembly, and he always replied promptly with detailed answers.

Definitely would recommend.

Next post will be a review of the MakerFarm Prusa i3, as well as modifications I’ve done to it that, I think, makes it an even better machine.