The last prominent feature of the Replicator is its large build envelope. At 8.9x5.7x5.9 inches, the Replicator lets you build the largest objects of any consumer-level 3D printer. However, successfully achieving maximum-size prints can be difficult since large objects are prone to cracks due to uneven cooling. It would also take hours to print something that big. Despite those challenges, it's of course better to have the option for large prints than not.
Actually printing an object on any 3D printer is exhilarating the first few times you do it. You may find yourself enrapt by the process, watching the print head extrude the material layer by layer for 30 minutes or more until your object is complete.
Alternatively, after your fourth failed attempt at a 2-hour print, you may need to walk away for the day.
As it turns out, printing in three dimensions can be unpredictable. The plastic doesn't always adhere properly, either to the build platform or to itself. Other times the plastic doesn't melt quite right, giving you unsightly globs, gaps, or wispy tendrils that disrupt the print.
Printing in two colors can be equally a give and take. To print a two-color object, you need to use ReplicatorG and Skeinforge to merge two STL 3D object files into a single, combined gcode file. You can't currently print a two-color object with support material yet, but once you've generated the combined gcode, the process is the same as printing a single-colored object.
Two-color results can look great, and blending experiments hint at the potential to make objects with nuanced color characteristics. Sometimes the two object designs don't merge quite right though. Other times the two different filaments don't adhere to each other well enough.
Adjusting the software settings is one way to troubleshoot a print, and you might solve a problem by slowing down the motion of the extruder heads or increasing the temperature of the build platform. You should also maintain a clean and properly calibrated build platform.
Some of the difficulties you will encounter, though, are due to general characteristics of the ABS (acrylonitrile butadiene styrene) or PLA (polylactic acid) plastic filaments. Each material wants to print at certain temperatures and at certain speeds, both of which can vary depending on the design of your object.
Other issues, like when the idle extruder head interferes with a print in progress as it passes over, are specific to the Replicator.
To a certain extent it's fruitless to complain about the general problems of 3D printing. Between the open-source software and the industry-standard plastic filaments, 3D printing is still in its early stage as a consumer-level activity. It would also have been nice if old micro floppy disks had held more than 1.44MB, but the technology at the time simply wouldn't allow it.
For the Replicator specifically, two issues with its design could stand improvement.
First, enclosing the build platform in the wooden frame makes for a tidier overall appearance. It also seems to provide convenient anchor points for the print head's X- and Z-axis drive frame. The problem comes when you want to replace the Kapton tape on the build platform.
Kapton tape is an insulator, and it helps ABS adhere to the build platform. You need to wipe it down between prints using either acetone or rubbing alcohol. It's also susceptible to tearing, especially if you use an implement to pry your finished prints off the build surface.
Once the Kapton tape tears enough, you need to replace it. MakerBot kindly includes a roll of 120mm tape in the Replicator's box, but the enclosed frame impedes access to the build platform, making it very difficult to apply the large sheets of tape accurately. I had a roll of 25mm Kapton tape left over from the MakerGear Mosaic 3D printer, and those narrower strips were much easier to apply smoothly. The fact that I had to use six pieces of 25mm tape didn't seem to prevent good adhesion, either.
MakerBot says it's working to improve the process of reapplying the Kapton tape. As a short-term fix, I'll suggest adding a couple rolls of 25mm tape to the box.
The other issue alluded to above has to do with the second extruder.
The two extruders come attached to a single print head assembly that you connect to the drive sled via a pair of hex screws. The extruders are level with each other (or should be), but when the path of the extruders brings the idle head over a print-in-progress, occasionally the second head can exacerbate printing errors by catching on stray strands of plastic. The idle head can also stain an object when it passes over if the head has residue on it from printing with a different color.
Solving idle head pass-over issues is more complicated the applying new tape. A mechanism to raise and lower each extruder head independently would certainly add to the cost of the printer, and potentially introduce other complications. The extruder heads are threaded, so you could technically unscrew them, but it's not easy with the current design.
Whether your print suffers from a general problem of 3D printing or an issue specific to the Replicator, part of the challenge for some of you, or maybe the appeal, will involve spending time experimenting with the printer.
I had a good stretch of success with my first few prints on the Replicator. I printed three of the sample projects on the included SD card. I also printed a two-color CNET logo I designed myself in Google SketchUp.
After the second day of printing, I found that objects frequently wouldn't stick to the build platform. I changed the Kapton tape, cleaned it with acetone between each print, and finally, on the advice of MakerBot support, made sure to calibrate the platform as close to the extruder heads as possible without touching. All of that solved my problems for most prints, but there are still objects I found on Thingiverse I haven't been able to print successfully.
That others have printed those objects tells me that it can be done, it might just be a matter of tweaking the printer settings. What those settings might be, I haven't found yet. Some Thingiverse listings include custom settings, but not all. Even when they do, applying special settings doesn't guarantee success, perhaps due to your build environment, or your specific printer.
The thing about repeated trial and error in 3D printing is that it takes a while. Print time varies by the size and complexity of each object, but some objects can take 10 hours or more, especially if you use a full support structure (a lattice work of thinner plastic that supports overhangs; Skeinforge automatically calculates the support structure if you select the option, and you break it off once the print is finished).
Even for short prints that fail in the early stages, it takes time for the software to process the gcode (the bigger the print, the longer the processing time) and for the build platform and the extruder heads to heat up. Twenty minutes or so between trials isn't out of the ordinary as a minimum, and over three or four tries the time spent experimenting adds up, even with small prints.
Some people will relish the opportunity to dig into brand-new technology like this. If not, MakerBot wouldn't have such a passionate community on its Thingiverse site (15,000 user-uploaded object plans and counting, available for free) otherwise. You will also find a vast trove of online help available from MakerBot and its community members. The information is useful, but it's also scattered among various Google Groups, wikis, MakerBot's own documentation, and elsewhere. Finding help can become a hobby in itself.
If I've concluded anything from this review, it's that 3D printing is an inspiring activity, although it can be frustrating and demanding of your time. It also seems certain to grow in popularity. Crafters, hobbyists, and design professionals will likely integrate 3D printing into their routines, and it is an obvious educational junction point for art and science. It has the potential to become one of those generational-gap technologies that kids pick up naturally.
That doesn't mean I would buy my daughter a $1,999 3D printer and tell her to go to town. I might consider buying her a $500 model, but the Replicator is too expensive for simply noodling around on. I would, however, vote yes to funding the purchase of a Replicator for her middle school.
For professionals and hobbyists, your needs and your budget will vary. If you don't care about multiple colors, or can't spare the time to use the Replicator to its full potential, a more affordable 3D printer, or even an on-demand 3D printing services like Shapeways would be a better alternative.
3D Systems will release its much-hyped Cube 3D printer in a few weeks. A single-color printer for $1,299, the Cube is directly targeting consumers, more so than the consumer-professional-enthusiast mix MakerBot has on its radar. If 3D Systems can nail the software experience and improve some of the uncertainty involved in 3D printing, it will be able to call the Cube a success. I'm also curious to see what kinds of compromises are involved in the $500 Solidoodle 2.
If either of those products offers a dramatically improved experience from that of the Replicator, I may review my assessment. For now, the MakerBot Replicator is the best 3D printer available for under $2,000. It's not a toy, but rather a challenging, thrilling creation platform. If you have the time to invest in learning how to use it, you will surely be rewarded.