From his dorm room, first-year student Ethan Gao is building a folding 3D printer that packs into a backpack with its filament spool inside.
Gao calls the machine P2, and it is his second run at the idea. The first version appeared on X in June, just after he finished high school. It folds flat, runs its CoreXY motion on fishing line instead of belts, and rises on a scissor lift to print objects taller than itself. By September it was printing, with what Gao called “plenty of issues” still to solve.
P2 pushes the same trick further. Folded, the new design should measure about 300 by 300 by 80 mm, and opened up it should print parts as large as 175 by 180 by 200 mm.
That works out, by Gao’s own math, to 87 percent of the machine’s physical size becoming build volume. He puts most fixed-frame printers at 10 to 25 percent.
This is a 3D printer that is small enough to fit in a backpack.
Unfolded it can print up to 175x180x200mm. Folded it’s about 300x300x80mm. 87% of its physical size becomes build volume. For reference, most fixed frame machines hover around 10-25%.
Think this is compact? What if… pic.twitter.com/cSmSVSgLt5— Ethan Gao (@ga0_lab) November 3, 2026
The spool is what sets it apart. The Positron, an upside-down folding kit from the Positron Team and printer-parts maker LDO, packs into a hard case, yet its power supply and filament are carried separately. You unfold it, set it up and plug everything in before the first layer goes down. P2 is meant to carry a whole spool inside its folded body and to run off power tool batteries, so there is less to pack and less to connect.
Most of that is still a plan. P2 is also due to get a heated bed, and together with a full enclosure that should let it handle ABS and similar materials. Armor is planned for the scissor arms, which Gao himself calls fragile. What the post actually shows is the open-frame prototype on its black scissor arms. In one clip it prints a vase. In the other it sits in front of a CAD render of an enclosed design.
Gao is not working alone. He brought in James Lin, a high school student who posts as @JamesMakes29, after spotting his projects on Instagram. Together they aim to finish P2 before the end of the year.
The deadline is personal. P2 has to be built by January, when Gao starts work, and his X bio lists him as headed to Neuralink. Money is tight too. Aluminum parts and PPA, a polyamide filament, are adding up, and Gao has asked anyone willing to help fund the build to message him.
There is no price, no kit and no launch date. For now P2 lives on a monitor, behind a prototype that already prints.
Source: Ethan Gao on X
