Bits to Atoms: Ultimaker 2 3D Printer Review

By Sean Charlesworth

Between quality of construction, fine resolution prints, speed, a large print area, heated bed for multiple materials, and software that accommodates novice to expert, The Ultimaker 2 is as close as you can get to quality that just works with a minimum of fuss and room to grow.

We spent a month with the Ultimaker 2, a high-end FDM 3D printer and it was a positive experience all around. Ultimaker is a Netherlands based company that introduced the Ultimaker printer kit in 2011 - a standard at Maker Faire along with the MakerBot Thing-O-Matic, introduced in 2010. Aside from the many RepRap kits available at the time, Ultimaker and MakerBot were the ones people like myself were looking at. Both kits had a similar look with lasercut plywood bodies, but the Ultimaker used a different approach to how the filament was fed through the extruder and how the larger print bed operated. From the start, Ultimaker was know (and still is) for very nice, high resolution prints. The only thing that kept me from buying the Ultimaker over the Thing-O-Matic (which I loved) was the fact that MakerBot was located right in my neighborhood, Brooklyn, and Ultimaker was way over in the Netherlands with no real US-based support at the time.

Photo credit: Ultimaker

The Ultimaker 2

Ultimaker Original+ Kit CREDIT: ULTIMAKER

Things have changed quite a lot since then, with MakerBot being bought by Stratasys and becoming a household name and Ultimaker expanding across Europe. Ultimaker has now secured a U.S. partner, Fbrc8, which assembles, distributes and supports printers domestically. Currently Ultimaker offers the Go, 2 and Extended models as well as the Orginal +, an updated version of the first kit!

All of the printers use 2.85mm PLA filament with a .1mm (100 micron) standard layer resolution, down to an amazing .04mm (40 micron) fine resolution. On many FDM printers .1mm is the 'high' setting. All printers have a removable, glass printbed for easy print removal and clean up. The $2500 Ultimaker 2 has a 22.3cm x 22.3cm x 20.5cm heated print bed which expands the printable materials. The Extended is identical to the 2 but adds 10cm to the printable height and runs $3000. The tiny Go has a 12cm x 12cm x 11.5cm build volume and does not have a heated print bed, so is restricted to PLA filament--it runs $1300.

CREDIT: Ultimaker

The Ultimaker is a pretty machine to look at and just looks cool sitting on your desk. The main body is a nice laminated wood sandwiched aluminum construction with thick frosted, plastic side panels. The print platform is sturdy all-metal construction and the interior is well lit with adjustable white LED ribbons. Printing can be performed via USB or the on-board SD card reader via the click and push scroll wheel control. It's also worth mentioning that Ultimaker has remained open source and the Ultimaker 2 design files can be downloaded here.

The Extruder

One of the major differences between the Ultimaker and other commonly seen consumer printers is the use of 2.85mm filament with a bowden extruder. Most printers that the general public sees (MakerBot, Dremel, Cube, Leapfrog, etc) use a direct drive extruder where the motor that feeds the filament through the hot end (where it melts) is attached to the X-Y gantry. The Ultimaker has always used a bowden extruder where the drive mechanism is mounted to the back of the machine and the filament is pushed through a tube to the hot end, which is the only item attached to the X-Y gantry. This set up greatly reduces the mass of the print head and allows for much faster printing speeds.

2.85mm Filament Bowden Extruder

The trade off is bowden extruders may take a little longer to load and unload and typically need to use 3mm filament versus the more common 1.75mm used on direct drive machines. Since the bowden extruder is pushing the filament the whole way from the back the sturdier 3mm filament is needed. A point of confusion arises, as I have always heard the Ultimaker referred to as a 3mm machine but it actually uses 2.85mm filament which is more common and often referred to as 3mm. Confusing due to the fact that there is also actual 3mm filament, but my understanding is that you will typically find 2.85mm filament at most distributors. The 2.85mm filament and bowden extruder work very well on the Ultimaker and they have no plans on changing that. The selection of 2.85mm is plentiful and if you're new to 3D printing, should cause you no hesitation when buying a printer. As an established 3D printer, my only qualm about using 2.85mm filament is the fact that everything I currently have is 1.75mm!

Using the Ultimaker 2

Easily removed glass print platform.

The Ultimaker 2 was great to use with well thought out features. The glass print bed is easily installed via metal clips that hold it securely. It made removing tough prints a breeze and applying tape or glue stick for print adhesion easy. Hairspray or ABS slurry (ABS dissolved in acetone) are favorite adhesion methods for ABS and the removable bed makes application and clean up a lot easier. Replacement glass print plates are a reasonable $35.

The bowden extruder worked great for me, with no jams during printing. Loading and unloading filament was a little more involved than I'm used to, as I usually just heat the nozzle and pull out the filament. The Ultimaker has an automated system that heats the nozzle, then slowly feeds the filament until it's firmly gripped by the extruder gear, then it goes to high speed to feed the filament through the bowden tube. I had a few jams during loading, but the Move function located in the Maintenance menu allowed me to manually feed the filament via the scroll wheel and led to a successful load.

One of my favorite things about the Ultimaker 2 is how quiet it is. The stepper motors used on 3D printers can be noisy as they tend to 'sing' which can be really annoying on a late night print. I believe that the use of the bowden extruder is partially to thank, as the print head is very light and doesn't need as much force to drive as many other printers.

The Ultimaker 2 has nicely fleshed-out on-board controls accessed via the scroll wheel. Everything from LED adjustment, to filament settings can be changed right on the machine - a refreshing change from machines that let you change nothing. Most users may never even touch these settings but it's nice for advanced users. Another nice bonus was the extra hot end and temperature sensor included with the printer. I noticed that there was space on the print head and rear of the machine for another extruder and inquired if there were plans for a dual printing upgrade. Ultimaker had considering it but felt it was too complicated an upgrade for most customers and there were compromises in print quality. They did indicate that they are working on a dedicated dual-extrusion machine.

Print Quality

Robots .15mm - .1mm - .06mm resolution

Prints turned out well across the board with no failures or jams other than some adhesion problems with ABS (not unusual). Most of the prints were done with PLA and turned out great with very fine resolution. The Ultimaker even handle some typically problematic models very well. I ran a series of the Maker Faire robots that Make magazine uses for testing printers and they all turned out well other than the lowest quality setting. Even that one is not too bad other than a messy layer toward the top. I didn't get a chance to print the robot at the Ultra setting (.04mm layer) but the High setting (.06mm) turned out great, it's hard to even see the layers. Details on all prints were very good, with minimum clean up needed. Supports worked well and cleaned off easily. I did notice that I needed to use a higher infill percentage than I was used to, in order to get a clean top layer. Typically I use around 10% on my MakerBot with great results. On the Ultimaker I had to use 15-20% to get a clean top with no gaps. This could probably be improved by tweaking settings in the Cura print software. The extra 5-10% infill did not use significantly more material, but it does add to the print time.

10% infill showed gaps on top layer

With PLA I printed directly on the glass at 60℃ with no problems, just make sure to keep it clean (ie: no fingerprints) with some alcohol. ABS, my favorite material, is a lot more thermally dynamic when printing and tends to warp and peel off the print bed much more than PLA. For kicks, I tried ABS directly on the glass with no luck, as it warped and peeled quickly - which I knew would happen.

Brim increased adhesion and in this case, cleanup

A glue stick is included to rub on the glass for better adhesion and I had better but not completely successful results with that. I tried the brim function via the Cura software which creates a large, thin brim around the print that helps with adhesion. It worked very well, but it was somewhat problematic for clean up with my model due to all the zig zags. I didn't try it, but traditional painter's or kapton tape should work great or alternative print surfaces such as BuildTak or Zebra Plate.

The Software

Ultimaker's Cura software is open source and supports third party printers other than Ultimakers. In that spirit, Cura outputs pure gcode, a machine language for drawing a model which can be editing with a simple text editor. This is in contrast to the trend of using proprietary, non-editable output files. Cura was completely rebuilt recently and this is the only version I have used. Overall Cura worked well, striking a nice balance between ease of use for beginners and access to advanced settings for pro users. In Quickprint mode you simply choose between Fast, Normal, High and Ultra quality and whether you want support material and hit 'go'. The Full Setting mode gives you access to layer height, infill ratio, print speed and more - all the essential settings for tweaking prints. But wait, there's more - an Expert Settings tab that gives you control of even more tweaks. One of my biggest frustrations with printing software is it being dumbed down to be 'fool proof' with either no advanced settings or crude (ie: editing a text file) methods of access. There's no excuse for such laziness and makes otherwise fine printers undesirable to advanced users. Ultimaker strikes a nice balance by having different setups to accommodate skill level.

Cura from novice to expert

Cura will do typical functions such as auto arranging models on platform, laying them flat, resizing, rotating etc. - no complaints here. If there are multiple models on the platform, there's even a 'Print One at a Time' feature which will completely print one item before moving onto the next. This is a nice feature if you are in a hurry or doing tricky prints that are prone to fail. Typically multiple items print by the current layer being printed for each item consecutively, meaning they finish printing at the same time. The feature doesn't work for all prints as the models have to be far enough apart on the print platform that the extruder doesn't run into finished models as it prints the next one.

Clockwise from top: Overhangs - Transparent - Xray - Layers

Other nice features are the ability to highlight overhang areas that are problematic to print, transparent and x-ray mode to see internal structures, and layer mode to see how they will print. If you insert an SD card, it gives you the option to write the gcode directly to it and even gives you an eject button - nice. Slicing a complex scene, such as Valcrow's lightsaber took 2 minutes, 40 seconds and saving it to disk was instantaneous. As a comparison, MakerBot Desktop took 4:46 to slice the same scene and a whopping 12 minutes to write to disk. Simplify3D ($149), a standalone, third party slicer, took 25 seconds to slice and 42 seconds to write to disk.

Cura bogged down with complex prints

It's not all roses, as I did have a few issues with Cura. There seems to be no way to 'Select All' for something such as scaling. I wanted to rescale all objects on the print bed and had to do it one at a time. The time estimates for prints also seems to be way off and from my observations it seems like the print time was based on the current layer and would vary wildly from layer to layer. My biggest gripe with Cura is that rather than hitting a button to slice the models, it continually processes the scene. This is fine in most cases, but with a complex scene like the lightsaber parts, it started to bog down and rotating or moving parts, caused lag and stuttering. A simple fix would to have a Preferences option to turn off on-the-fly processing.


CREDIT: Ultimaker

After admiring these printers at many Maker Faires, it was great to finally use an Ultimaker. The quality of both the machine and prints was top-notch. Some may ask what $2500 will get you versus a $1000 or less price point? There are plenty of great machines that costs less, but the Ultimaker 2 is a machine that you can grow into. Between quality of construction, fine resolution prints, speed, a large print area, heated bed for multiple materials, and software that accommodates novice to expert, the Ultimaker 2 is as close as you can get to quality that just works with a minimum of fuss and room to grow.

Also check out Will and I's video review of the Ultimaker 2.