Best 3D printed foam blaster: 10 designs worth printing

If the question is “what 3D printed foam blaster should I print first,” the Ontos by Impulse Ungineering is the current default. It is a pump-action primary aimed at people who want a game blaster without a Lynx-length hardware list.

The designer built it around one screw size and nine hardware items, and describes the bill of materials as about a third as long as an SBL or an Alchemist. The prime runs on metal bearings on a printed track, the shell prints flat, and the spring and barrel are meant to swap without tools. Later files use a common plunger tube (1.375 in inside diameter, or 35×38 mm metric tube) and standard #123 o-rings.

Impulse Ungineering says it easily hits 170–250 fps. Hardware-kit listings advertise a wider band, about 130 to 300 fps, depending on spring, barrel, and plunger length. Treat that as a tuning range, and pick the spring that matches your game’s cap. Files are free on Printables. Out of Darts sells a hardware kit if you do not want to hunt bearings and a barrel.

The Caliburn, by Captain Slug, is the mag-fed pump-action design the hobby still points new builders at. The printed file set is public domain. You can remix it, and a lot of later blasters did.

His 3D-printed assembly notes put muzzle velocity between 150 and 210 fps depending on the darts and the spring, and he tells indoor players to use the lighter springs (K31 and 788) rather than the stiff ones. The same notes say not to store a printed Caliburn in a hot car. PLA warps, and a warped sear is a bad surprise.

It is a longer, more hardware-heavy build than an Ontos. The reason to choose it is the decade of assembly PDFs, kit sellers, and people who have already broken the part you are about to break. Current files live in his file index, separate from the older machined-polycarbonate write-up.

The Lynx, by Dan at Orion Blasters, is the bullpup people mean when they want a short mag-fed pump that still shoots half-length darts hard. It slam-fires, it swaps magazines on a closed bolt, and the whole blaster comes apart without tools. It takes Longshot and Talon Claw springs.

Orion’s own page says it is most consistent from about 150 to 250 fps. Spring, barrel length, barrel fit, and the dart do the rest. Kit springs sold for it are often labelled by the velocity that shop measured with a particular barrel, so read the listing before you order the stiffest one.

The official hardware is imperial. Metric remixes exist, and they are not all interchangeable with each other or with the imperial kit. If you buy a kit and download files, match the version. The 2.1.0 set is on Printables as well as on Orion’s site. Print orientation is in the files, and the notes say no supports, with about four or five walls.

The Talon Claw 4 is Captain Slug’s compact short-dart pump. Where a Caliburn is a primary you sling, a Talon Claw is the blaster you actually carry between games. It is magazine-fed, built on flat aluminum bars, and sold as cut-to-length hardware kits with a couple of barrel lengths and a short menu of springs.

Pick it when you want Talon magazines and a real springer, and you do not want to print a rifle. The files are in the same Captain Slug index as the Caliburn (look for the T4 zip). Kit sellers link those STLs from the hardware page, which is the sane way to buy the bars already drilled.

Sillybutts uses the Talon Claw as a benchmark on the Alchemist page: with the same barrel and spring, he expects the Alchemist to land about 20 fps lower, because the Alchemist uses a shorter prime. That is a useful way to think about this blaster. It is the reference compact springer, not a side project.

The Alchemist, by Sillybutts, is a pump-action springer for people who have already built one blaster and want the prime to feel finished. It uses aluminum bars, like a Lynx, plus a bar tensioner that pulls the stack together. The barrel comes off in about ten seconds with no tools. Stocks include a printed fixed stock, a Worker-style adjustable stock, or none.

Sillybutts publishes a reliable band of about 120 to 260 fps, depending on spring and barrel. It takes Talon Claw length springs and the longer Lynx and Longshot springs. He is explicit that the shorter prime is the trade for that smooth feel, and that a K26 or anything stiffer than the design point is how you break parts for a small gain.

The body bars are custom lengths. The file set includes a cutting and drilling jig, which you want if you are not buying a kit. His file page also says this is a hobbyist blaster, not a toy, and asks for a bright orange muzzle. Read that before you print the pretty colour all the way to the barrel.

The SLAB (Silly’s Lever Action Blaster) is the one to print when a pump grip sounds dull and you still want Talon magazines and half-length darts. It is a lever-action springer, designed around PLA, and it has a pile of community magwells and barrel parts because people actually finished them.

The designer’s setup is 4 inches of K25 and a 12 inch barrel, which he says should land around 220 fps. Springs from about 4 to 6 inches fit. He also says K26 and K14 will fit and will cause durability problems for little extra performance. Believe the person who broke them.

It is a worse first blaster than an Ontos or a Caliburn. The lever, the ram seal, and the bar cuts are all places a first build goes sideways. It is a great second blaster if the goal is “I want to cycle a lever at a war this weekend.”

Every other blaster on this list is a springer or a stringer. The Gryphon, by Flygonial, is the mostly-printed semi-auto flywheeler. You print the shell, the cage, the pusher, and the magwell, then you still have to wire motors, a switch, and a battery. That is the whole point. Rate of fire comes from wheels, not from your arm.

The file page is unusually clear about fit. Cages take common 33 to 38 mm hobby flywheels on 2 mm shafts. Magwells exist for Worker Talon magazines, for Katana-geometry magazines with a lower release cutout, and for ordinary full-length magazines. If your bin is full of old full-length sticks, start there and convert later.

There is no honest single fps number, because the wheels, the crush, and the pack decide it. Read the designer’s cage notes and use a hobby setup people in your group already run, so someone can tell you which motors they melted. Files are on Printables and GitHub, and they were still being updated in 2026. A solenoid pusher and a LiPo are a different project from nine screws and a spring. Print this when you want that project.

The Catfish, by Bruce at Leedle Dynamics, is a bullpup for people who do not want to buy a plunger tube, aluminum bars, and a named spring. Power is 4 mm elastic cord (5/32 inch cord also works). Magazines are straight Worker Talon magazines or a printed equivalent. The file is a paid Printables download, which is worth knowing before you click.

The interesting parts are the ones that usually cost metal. There is an optional internal BCAR, the pump can slam-fire, there is a picatinny rail under the grip, and the pusher is skinny enough to drop a magazine while the action is closed. Optional o-rings (#012, #016, and two #123s) replace fussier printed seals if you can get them.

Plan on about a 180 mm bed, and on angling the long parts if your printer is smaller. Print settings are in the folder names. He does not publish a single fps, because a stringer is tuned by how you rig the cord. That is the feature and the footgun. Tie it for the game you are going to, and leave a way to detension it in the car.

The Tilapia, also by Leedle Dynamics, is the free answer when you want shells instead of a magazine. It is a low-hardware repeating foam blaster with a five-shot capacity, string for power, and a visible ejection. The long version is the one he tells you to build. It is only about 3 cm longer than the short frame and, in his words, performs vastly better.

Hardware is 4 mm elastic, about 1.6 m once you include the knots, and optionally two #123 o-rings plus one #016 so you can skip rope seals. He asks for a printer with about a 180 mm bed, no supports, and roughly 1.3 kg of filament. Folder names carry the wall counts. A revised bolt with a different o-ring groove showed up in 2026 for people whose first seal would not hold.

Shells that sit inside the gun are the intended magazine. Full-length Mega and Mega XL are a different loading problem, which he points at separately. Build the long version, in the filament colours the folders expect, before you invent a short one.

The PK Squire, by Print Keep, is the small end of this list on purpose. It is a front-loaded single-shot springer: a cut-down K25, an aluminum barrel, a short parts list, and a manual in the file download. Print Keep calls it a beginner’s first foam blaster and says a careful build can reach about 2 joules, around 210 fps. That is plenty for a first chrono, and it is also why the manual’s safety page matters.

Expect on the order of 27 hours of printing and a handful of purchased parts. The handguard is M-LOK, so a grip or a sight is a later-afternoon change. Hardware kits and complete kits are listed for the US and Europe on the file page if you do not want to cut a spring.

Choose the Squire when you want to learn a plunger, a barrel, and a seal without also learning a magwell. Choose the Ontos when you already know you want a primary for a game. Both are honest first prints. They are just different Saturdays.