Different cage geometry featuring dovetail joints to lower.stl, much tighter dart guide to prevent darts folding inside, slots for cable ties, slot for mosfet and arduino nano
Upper assembly slot together with dovetails, making the entire blaster more rigid and secure
Rear pic rail is now bolted to the stock point rather than using heat inserts, makes it a lot more secure
Slightly different flywheel geometry to fit the new cage dimensions, shouldnt affect FPS
New cable guides in the lower assembly, easier to route cables and less likely to strike any moving parts
Slightly less hardware, 2 heat inserts have been replaced by 2 M3 nuts
.STEP file updated with all new changes
11/05/2023
Found that shaft hole for flywheels was too wide, making it difficult to align flywheels to the motors properly, tolerances adjusted
17/04/2023
Added a thicker wall behind the magazine on the cage to prevent darts behing pulled back by the pusher
Reduces pusher length by 1mm to further remedy the above
Adjusted tolerances on the Lower, selector switches should now fit in place better and the grip portion should be easier to print
Fixed minor errors in Rail Rear and Stock Point
Arduino sketch slightly adjusted for a faster rev down time
10/03/2023
Adjusted the flywheel cage spacing by 0.1mm to compensate for possibly flywheel rubbing
04/03/2023
Published
This is my take on a Nerf dual stage brushless flywheeler, the GnK-200!
I aimed to create a blaster that is slim, variable power, lightweight for what it can achieve, and maneuverable. This consists of 4x 1404 size brushless motors, a solenoid, selector switches for variable RPM and select fire, and a 2 stage trigger to maximise response time between revving and firing. GnK-200 takes straight talons and its derivitives, including the Out of Darts Tachi magazines, as well as a picatinny style folding stock. The muzzle is also able to take any kind of 19mm ID faux barrel, including Worker muzzles and the Black Raisins flywheel tracer unit.
I have chronoed this to 200fps, this may be higher or lower depending on your build quality and motor setup, but I have easily hit this on 4500KV motors with a smooth bore barrel and fresh darts on a fully charged 3s Lipo. Default settings in the arduino sketch are for low RPM, 130FPS, and Max RPM. This may change dependent on your motor selection once again.
I have opted to make this blaster Lipo in grip, and I usually go for the largest lipo I can fit inside, and I have managed to fit in a GnB 2200mah 3s 100C Lipo with an extended battery lid, which means most batteries used in the nerf scene will work with this.
Firmware is included, I will admit this is not the prettest, but it works to get the blaster working at a minimum. You are welcome to use your own firmware, different microcontroller, add a screen, whatever you like with this! I would love to see what others can do with this shell.
As seen in the images for my version, you are able to hydrodip this blaster easily at home! I'd highly recommend dipping the upper cowl in two halves, otherwise the hydrographic film will stretch too far up the sides and tear.
This project is licensed under the terms of the Creative Commons Non-Commercial Attribution Share Alike 4.0 license, which means you can print it, remix it, share it, and if you do and give myself credit. You cannot sell this without permission from myself.
Pinout/Wiring Diagram for Arduino Nano:
D2 = MOSFET
D3 = Rev Switch
D4 = Trigger Switch
D5 = Right RPM Switch 1
D6 = Right RPM Switch 2
D7 = ESC 1
D8 = ESC 2
D9 = ESC 3
D10 = ESC 4
D11 = Left Select Switch 1
D12 = Left Select Switch 2
Hardware (Main):
12x M3 Heat Insert, 5mm OD, 4mm Height
13x M3x6mm Bolts
2x M3x12mm Bolts
2x M3 Nuts
1x M3 Thumbscrew
4x M2x10mm Bolts (For mounting the microswitches)
2x small springs for Trigger and Mag Release (I don't have measurements for these since I cut down assorted springs)
2x 3mm x 14mm steel dowel pins (I had loads leftover from making BCARS)
4x Axis C145 1404 4500KV Motor / Axis Flying AF144 4510KV Motor / BrotherHobby TC 1404 4600KV Motor
24x M2x6mm Bolts (For motor and flywheel mounting, HIGHLY recommend they are button head bolts for minimum height clearance)
16x M2 Washers (Optional but highly recommended for the motor mounting, saves the bolt drilling into the flywheel cage too far)
1x BLHeli_32 4in1 ESC (30.5mm and 20mm mounting holes are both included on the flywheel cage, MUST have less than ~7mm height to fit in the shell, I used a Diatone Mamba 45A ESC F45_128K with the JST connector removed)
1x Arduino Nano
1x Buck converter/BEC
1x Neutron Solenoid + 4x M3 bolts
1x MOSFET board or kit to drive the Solenoid
2x 3 Pos switches (SS-23D32G6)
2x Subminiature Microswitches
1x XT60 Connector
16 AWG power wires
22 AWG signal wires
3s Lipo/LiHV, 24x34x106mm max size (with extended battery lid)
Small cable ties
Hardware (Folding stock):
2x M3 Heat Insert, 5mm OD, 4mm Height
1x M5x24mm Bolt
1x M5x12mm Bolt
2x M5x10mm Bolts
4x M5 Nuts
1x M3x30mm Bolt
1x M3 Nut
You can switch out and use your own electronics if needed, if you want to use different motors, make sure to double check the measurements on the flywheels and motor mounts to see if they will fit.
Build Notes:
I'd highly recommend printing the cage in PETG or any other heat resistant material, and the flywheels in ABS. I have tested PLA flywheels and they worked well enough, but you may have a different experience.
Pay attention to the Lower assembly when printing, as the walls on the grip can be quite thin.
Loctite your bolts into the motors, or at least periodically check they are screwed in. I have found that using the M2 Washers for the motor mount bolts have helped significantly in keeping the motors secure without cracking the flywheel cage.
Some parts may need supports when printing, such as the lower and stock mount, I will leave that up to you for support placement.
If using the pic stock included in the files, I'd recommend lubing up the pivot assembly for smoother operation, and a TPU buttplate is also recommended, but not required.
For further questions and support, please ask in my discord (Link in printables bio via Instagram).
MeinGonk
