As I finished up my undergrad degree and my student job managing 3D printing for Huntington University, I was asked to set up a new 3D printer, the Form 1 from Formlabs. The Form 1 is a 3D printer that uses the photolithography technique to harden resin in micro-thin layers and was supposed to be much superior to our Makerbot Replicator. The Form 1 is better in many ways, but it has drawbacks also.
Setting up the Form 1 was straightforward and took only about 20 minutes. The included quickstart guide and the online documentation was easy to follow, and the process was uncomplicated. The only real trouble that I had was trying to figure out which of the extension cords and surge protectors was unplugged.
Once everything was set up, however, the real frustration started. After loading a model into the PreForm software and sending it to the printer, I waited about 14 hours and discovered that the model had come free of the build platform, resulting in an incomplete print. I tried again with similar results. Every following attempt resulted in zero percent completion before failing.
Despite these failures there are several advantages to the Form 1, as well as drawbacks. The Makerbot 3D printers also have different advantages and disadvantages, and I will attempt to compare the two here.
Another thing is calibration. The Form1 does not require any calibration, but it also cannot be recalibrated if there is an issue. The Makerbot, however, requires frequent calibration, particularly in regards to the height of the build plate, but also the stepper motors need minor adjustments when precise dimensions are required. The benefit here is that, unlike the Form1, the Makerbots are easy and relatively straightforward to calibrate.
Cost is another significant factor when comparing these two different kinds of 3D printers. Besides the different price points of the actual machines, the material cost is quite different. Formlabs sells the photoreactive resin for their printers at $149/liter, while Makerbot (which sells some of the most expensive plastic filament), offers standard ABS at virtually $50/liter ($48/kg / 0.96 liter/kg).
Detail is also an area where the Form1 excels. The machine has a minimum layer height is 0.025 mm, compared to Makerbots that can print layers as thin as 0.1 mm, possibly less under experimentalconditions. The Z accuracy is also higher on the Form1, giving a smoother look to walls even on identical layer resolutions. The minimum feature size on the Form1 is smaller as well, 0.3 mm, instead of 0.1 mm. However, the 0.025 mm layer height is particularly unreliable.
The software applications provided for both machines are fairly similar. Formlabs’ Preform software is, in my opinion, the easiest and most intuitive to use. The settings are simple and often can be used at their defaults. Makerbots’ MakerWare is also relatively nontechnical and easy-to-use, but it does need some tweaking. There are also a range of advanced settings hidden away, which makes the program both less intimidating, and somewhat aggravating for intermediate to advanced users. These settings are either not applicable to the Form1’s SLA process or simply left out.
On the more mechanical side of things is the ability and ease of removing prints. When working with the Makerbot, there were some prints that I remember as being troublesome in removing, mainly when the print had a wide base and/or when I used PLA plastic.The Form1 has a little less trouble using the provided scraper (the prints do adhere firmly to the platform, which is a good thing); however, when the prints do not stick to the platform they stick to the bottom of the tank. The user must then stop the print and use the scraper to remove the cured resin. The problem here is that the bottom of the tank is made of optically-clear silicone and susceptible to damage, ghosting, and pitting. If the silicone layer becomes damaged, it will cause degraded print performance and more failed prints and must then be replaced. Makerbots, on the other hand, leave only strings of plastic in the air or odd melted shapes after failed prints. They are reasonably forgiving in terms of rough handling and have no delicate parts that are easily damaged.
Finally, the last couple of topics that I would like to mention are support and infill. Supports are important for either system as printed parts need to be braced in order to print correctly. The consequences of having too little support material or none at all are drooping parts, ‘stringy’ plastic, or bits of resin stuck to the Form1’s tank. Supports are printed as needed on Makerbots, while the Form1 handles this by using supports in every print. The prints on the Form1 are, in fact, suspended above the base to facilitate removal. I have found both methods to work well; however, the Form1 seems to have a lesser problem with overhangs. The supports also seem to be easier to remove and clean up, whereas the Makerbot printer occasionally required hours of chiseling and sanding to get a nice finish.
While supports are an important part of the exterior of a print, infill is the interior of a print. Literally it ‘fills in’ the inside of a print. Infill prevents a print from being a hollow shell and gives it strength with an efficient structure. While infill does not technically apply to the Form1, I still view the comparison as important. The Makerbots handle infill as described according to an amount decided by the user, usually 10-15%. The Form1 does not use infill, instead it makes prints that are solid, leading to a waste of time and expensive resin. The only way around this is to model hollow prints. For many models, this is not difficult, but hollowing out character models is something that I have yet to master. Given that my university regularly needs to print character models, this is a significant problem.
In conclusion, the Form1 excels in most areas, although the Makerbot is a better option in others. If cost is a factor, then you may want a Makerbot or similar FDM machine. The Makerbot also, as I mentioned above, has a better track record and is a clear winner where the important factors of repair and reliability are concerned.