Almost all of the consumer and prosumer 3D printers on the market are fused-filament fabrication types, but SLA (stereolithography) printers are rapidly gaining popularity. That’s because they offer better detail and surface quality, and their prices have been dropping dramatically. But the vast majority of those budget SLA are either DLP (Direct Light Processing) or LCD-masked. Laser SLA 3D printers are much more expensive, but can offer a next-level experience. Bunnie Huang’s teardown of the Formlabs Form 3 3D printer reveals all of the hardware that you’re paying for.
All SLA 3D printers form layers by curing photosensitive resin with UV light, but there are many ways to accomplish that. The cheapest SLA 3D printers shine UV LEDs through an LCD panel, which masks the light as necessary. Mid-tier SLA printers use DLP projectors to accomplish the same thing, but with better results. The highest-quality option— which just happens to be the original type of 3D printing — is to shine a laser beam directly into the resin. That’s what the Form 3 does, but it has a number of improvements over other laser SLA 3D printers, including its own predecessors.
As Bunnie explains, one of the most noteworthy advancements is the unique single-dimension laser mirror galvanometer. The mirror galvanometer directs the laser, but most printers do that in two dimensions. The Form 3 only uses the galvanometer for the Y axis. The entire LPU (Light Processing Unit) is moved across the X axis on a lead screw. That helps to protect the sensitive optics from spills, smoke, and dust. It also shouldn’t affect performance too severely, as it only needs to move across the X axis in small increments between passes.
Another interesting feature of the Form 3 is its unusual construction, which Bunnie describes as “more aligned with automotive or aerospace design schools than consumer electronics.” All of the exterior surfaces are stamped, bent, and formed sheets of aluminum that attach to the internal frame with special fasteners. Those aluminum panels wouldn’t look out of place in an automotive body shop. Even the large acrylic cover appears to have been cast as a single part, which Bunnie says in an impressive feat.
Bunnie also gives high marks to the user interface, the large display screen, and even the power supply. A lot of engineering thought also obviously went into the resin filling system, tank heater, and LPU. There aren’t many Form 3 users who actually need to know this much about their printer, but Bunnie’s teardown does a fantastic job of illustrating the costs that have gone into developing and building the machine. The Form 3 retails for $3,499, which certainly isn’t cheap. But after knowing what kind of hardware inside, we feel like that’s actually a bargain.