Phantasm - A brushless foam dart blaster

2026 Update:

Phantasm is confirmed to be buildable with the Trifolium PCB and code. You can buy it here. With the lack of Flyshot ESCs this is now the recommended way to build one of these. The included build guide is meant for the DPI Spirit PCB using Flyshot or PWM code, but you can find documentation on Trifolium on the store page.

Beefier grip variants have been added- Detachable Strix grip and a thicker version of the default grip. Not exported as stls; see the step file to get these.

Phantasm is a brushless flywheeler meant for competitive play. I wasn't happy with the available options at the time, so I made this.

This is NOT an easy build for people who do not know what they are doing. This build requires a well tuned printer and varying materials (at least PETG for the cage area). The build should be relatively straightforward with the documentation I have provided. Please don't contact me to ask questions that can be answered with a quick Google search or by reading the documentation.

Features:

• Closed loop control with Trifolium or Flyshot-the blaster will only fire when both wheels are spinning the correct speed for maximum consistency and lowest spinup time.

• Adjustable muzzle velocity from 0-225 fps. On Flyshot/PWM, there are three pre-configured profiles for 130, 160, and 200 fps (with good darts), and a tournament mode.

• Configurable settings menu-FPS, Burst count, full auto and burst rates of fire, spin down time, battery cutoff, and fire modes are all settings that can be changed.

• Quick change muzzle device- BCARS/PCARS simply thread into the flywheel cage. I recommend the PCAR for general use.

• Two variants-Phantasm, which resembles an MP5k, and Phanta, which has a much safer silhouette and is minimized as much as possible.

• 3 code variants-Flyshot, PWM, and Trifolium. The Flyshot version uses EOL SimonK escs, but it is buildable with AM32 escs running the provided PWM code or Trifolium.

• Highest rate of fire out of all the Hycon designs- Phantasm maxes out at 20 darts per second (could probably go higher with a better battery)

• Flywheel idling mode in any profile, simply hold down the rev trigger when booting up. (except Trifolium variants, which uses the menu to toggle this on.)

• Dual stage trigger from GNK-200-Half pull to rev and full pull to fire.

• Battery in grip-Fits SBF/Momentum batteries.

• 3 position switch for select fire with assignable fire modes-Safe, semi, auto, reverse, burst, binary, devotion, reverse burst, fast full auto, and dual (half pull to fire in semi, full pull to fire full auto, like the AUG's progressive trigger).

• Robust menu-Settings are saved per profile, and the screen readouts have been improved.

• Universal magwell-Takes pretty much any straight half dart magazine. Even katanas. Has a dual magazine release, with ambidextrous buttons as well as a paddle. Phanta has an optional magwell flare piece that replaces the paddle. All mags should gravity drop (or you could flick them out 😎).

• 3 stock options-2 fixed folding stocks and 1 adjustable.

• The core is able to be transplanted into a different shell without any desoldering or connectors.

• HK Slap 😎 - You can put the blaster in safe mode by locking back the charging handle and disengage the safety by slapping it. (Flyshot and PWM code only)

Notes:

• This should go without saying, but please wear proper eye protection when playing, and don't print this in dark/realistic colors. I also recommend printing the muzzle in blaze orange to indicate that this blaster is a toy.

• If you are planning on using M5 shaft motors, you could cut the top part of the shaft, but it's not necessary as the cage cover would fit it.

• In theory you should be able to squeeze over 200 fps out of these wheels, but I do not recommend increasing the throttle over 80% or 1750, as you get a lot more heat, noise, and wear for marginal gains.

• This may not be as refined as other brushless designs because I'm not that experienced in designing things, but they work and I've already built 16 of these and we trust them enough to use them in tournaments.

• Parts are not oriented for printing-Print orientations and where supports are needed should be fairly obvious. Ophidian print settings should work here.

• If you are having trouble flashing the code to the board you might need to comment out the default splash in the SSD1306 library.

• I designed Phantasm around the Helibatics SimonK escs. Please keep in mind that different escs might not fit.

• Because the wheels are closer to the magwell, 3+ jungled mags do not work well here. It will probably feed, but I wouldn't recommend it.

• Cage and flywheels should probably be printed in a temperature-resistant filament (PETG, ABS, ASA, etc.) because the motors can get warm enough to soften PLA. ABS is the best as it's the lightest.

• Go wild with the steps, I want to see what people cook up.

Parts:

Phantasm shares a lot of components with Ophidian/Spirit/any other Hycon Neutron flywheeler.

• 1x Arduino Nano OR DPI Spirit PCB

• 2x Resistors to make a 16.8V → 5V voltage divider (47K/20K ohm)

• 1x Resistor for MOSFET gate to ground (10k ohm)

The parts above are included in the custom PCB.

• 1x IRLB3034 MOSFET

• 1x 1N5404 (or similar) Rectifier diode

• 1x 1N5357 Zener diode

If you are using Trifolium none of the above are needed. It can be found here

• 2x Kelly Industries Plus Motors (Plus Mount) OR 2x SunFun 2207 2450kv brushless motors (AliExpress) (not really recommended) OR 2x FLASH HOBBY Arthur 2207.5 2450kv brushless motors

• 8xM3X5 screws for mounting the wheels to Plus Motors (torx head preferred so you don't accidentally strip them)

• 8xM3X6 screws for mounting the motors to the cage (torx head preferred so you don't accidentally strip them)

• 1x 0.96" 128x64 SSD1306 OLED Display

• 2x 30-40A SimonK ESCs (must be Flyshot compatible) OR 2x 30A+ Single AM32 ESCs. A 30x30 4in1 like the Kelly Industries ESC will not fit, unfortunately

• 1x BEC/UBEC/Buck Converter unit, if the ESCs do not include it (not needed for Trifolium PCB)

• 1+ 4s battery- If it fits in SBF/Momentum it will fit in Phantasm. I use OOD GNB 1300mAh batteries and the DUPU SBF batteries. All other batteries are untested and might not work. I have heard of issues with the Tattu Momentum batteries not being good enough, so it's probably best to avoid them. (It could be because the battery is old or damaged though) I am not responsible for damages caused by improperly spec'd batteries. (Please don't put something like a Diana battery in this)

• 1x OOD Neutron solenoid, double sprung - Default spring AND high ROF spring

• 1x KCD1-101 SPST rectangular switch. I use the ones from this listing. Other sources might have issues.

• 1x 12 x 12 x 5mm momentary pushbutton switch

• 2x Subminature microswitch. (The lever style ones with the white bottom)

• 1x 3 position sliding switch. Should look like this

• M3 heat inserts- I use these 

• Various M3 screws, varying lengths of 4,5,6,8,10,12,20,30mm. A variety kit should work. 

• 16ga wire for the main power leads

• A bunch of jumper wires / hookup wire (24ga solid copper wire is best)

• 1x XT60 connector

• 1x M3x6-8mm thumbscrew for battery door-Strix grip needs at least 8mm length.

• 4x M2x10 screws-(torx head preferred)

• 3x click-pen spring for the mag releases and trigger (4mm diameter)

• 6 or 9x F683ZZ flanged bearings (for optional BCAR)

• 6 or 9x M3 x 10mm screws (for optional BCAR)

• Red loctite for securing the wheels/motors

• Heat shrink wrap

• Hot glue gun

• Soldering supplies

• Grease/lube-I use Superlube synthetic grease from OOD

Optional parts:

• 1x Subminature microswitch for the charging handle safety

• 2x M2x10 screws-(torque heads preferred) for charging handle switch

• 2x Machined Spirit wheels - printed ones would work fine. The machined options from Roboman or Kuryaka are meant for Plus Motors only.

• 1x Spring for the folding stock

• 1x Extension spring for charging handle. This spring assortment has springs that work in the stock and charging handle.

• 1x M2x4 screw if printing the split back left cover

• Various M3 screws and a M3 nut for the folding stock-You will need one at least 35mm long for the hinge part.

• For collapsing stock: Worker or SBL2 rod set, a pen spring, 6 more heat inserts, and 6 M3x8 screws.

• M5x30 and M5 nut for any stock option

• M3x30 and M3 nut for sling mount

• QD Sling Swivel for folding stock

• 2x M3 nuts if using the Strix grip

Possible features/ideas (probably not happening lol):

• More stock options

• Adjustable trigger group

• Rotary fire selector near the grip like Momentum/SBF

• New fire mode splashes

• Holster for Phanta

• More battery options-stock, drill battery, remote line, side compartment

• Latch or magnet on folding stock

• Adjustable iron sights

• Angled talon magwell version

• Different wheels/cage

• Different handguards

• UV led in magwell

• Operational briefcase

• Decorative "suppressor"

• Improve build process/optimize parts

• Improve grip ergo

• Protean muzzle device mounting

• Metal plate for motor mounting

• More muzzle options-SCAR/twisted PCARs/modular BCAR

• More firing modes

Updates:

10/8/2026:

• Beefier grip variants have been added- Detachable Strix grip and a thicker version of the default grip.

9/6/2026:

• Edited description to advise that this is buildable with the Trifolium PCB.

9/30/2025:

• Fixed geometry of the SunFun cage. FOR 2450/2500kv MOTORS ONLY! 2750kv is different.

• SunFun wheels now have indents that interface with the bell

• Holes in side of cage removed

• Added unchamfered/unfilleted picatinny rails to the step

• Added picatinny sling mount to Phanta for some additional color

• Optional magwell flare piece on Phanta can now also fit the paddle release

• New retractable stock option added: uses SBL2 or these Worker rods

• Various tolerances adjusted

• 3mf files added for coloring

• Suggested print orientations/support images added to build guide

• Basic Assembly Instructions updated

• Increased number of darts able to be fired on one trigger pull from 60 to 100 in the pwm code

• Reduced firing delay slightly in non-automatic/burst modes in pwm code

Acknowledgements/Credits:

• Flywheel geometry, code, and components from the Spirit

• SunFun motor geometry cage/wheels from Ophidian

• Trigger group from the GNK-200

• Code/Mag stand from GNK-200 Manatee edition

• Folding stock hinge from PP MCXish Folding Brace

• Fixed stock from NERF STRYFE UMP KIT

• Adjustable stock geometry from Strider Collapsing Stock

• Phanta sling mount from Sling Mount

• Grip from Strix

Thanks to all the hobby creators who keep their work open source, without remix culture things like this would not exist.