Darts will always get chewed up and the Rubber Band always tend to "jump" above the dart, causing jams.
The internals is rather complex and it requires the string to go under the dart. modifying this blaster is not only difficult, it is also unreliable as it will cause it to malfunction easily.
Internal shot of the Crossbolt
Then, there is the NERF Stryfe. A favorite with Nerfers all around the world.
Loved for its Simplicity, Reliability, Rate of Fire and Performance, there is hardly any games that this blaster isn't being used.
Modding capability is rather easy for this blaster, with aftermarket part makers creating various kits for performance and aesthetics.
because of the simplicity, you hardly ever find the blaster malfunctioning during games.
Internal shot of the Stryfe
The Kriss Vector Kit,
one of the most popular kits for the Stryfe
This project is aimed at creating and improving the function of the Crossbolt, without changing the look of the blaster.
Initial design process thinking:
during the initial design phase, I wanted to go with the same lever mechanism that the Stryfe used.
However, looking at the compact size of the Crossbolt, I figured that an electrical system would be more compact and with the possibility of it become fully automatic.
An example of the layout
Design and trial phase:A custom project usually means there aren't any parts readily available and a considerable amount of design thinking is required.
The first design problem I tackled was the design of the flywheel cage.
Initially, I went with a simple cage design. For the cage to hold the motors and wheels, nothing else.
but after considering the previous experiment regarding spinning darts increasing stability, I decided to add a 10-degree angulation on each motor post.
The original flywheel cage design
The beefier canted cage design
The canted flywheel cage
Next was the pusher mechanism.
I reused an electronic gearbox from another toy I had lying around and used that to push a "slide", which will be pulled back by a spring. However, because the blaster is a bullpup design, I had to figure out a way to push the dart into the flywheel cage, while the gearbox is seated at the front.
in order to hold everything in place, I made a jig to secure the slide, spring, and gearbox in place as I do not wish to glue them in. This is so that it will be easier to upgrade this in the future as everything is held in place purely by fitting and tolerance.
A small hook was added to the slide to accommodate the spring
The pusher mechanism jig designed to house the spring, slide, and gearbox
I cut and bent a hanger wire into a "hook" to be attached to the slide in order to pull the dart forward. However, it wasn't going far enough to feed the dart into the flywheels.
To remedy that problem, I designed a tip to be placed onto the end of the "hook" so that it will push the darts better and further.
Glue was added to fill the empty gaps between the wires at the hook end
The pusher tip is rounded at the tip to facilitate ease of feeding the next dart
Switch Placement!
The last few touches before we can close the shell up.
2 switches are required to run the blaster, a flywheel switch, and a pusher switch.
I used Omron switches, a small 5A switch for the pusher mechanism, and a larger 15A switch for the flywheel switch.
The reason for 2 different switches is because the pusher mechanism only have one motor, while the flywheels have 2. this would mean higher current will be drawn by the flywheel system rather than the pusher mechanism
The other reason is because the trigger has space for a spring to push it back, but the flywheel switch is too small to accommodate a spring, therefore it uses the spring from the micro switch to push it back.
Example for switch placement
Handle Jig made to hold the micro switches and triggers
The flywheel switch trigger
Prototype testing phase
some shell trimming was required to close the blaster nicely, but finally, the 1st prototype of the design is complete.
the power source I have available (Li-ion batteries) is insufficient to power the blaster properly but is capable of powering it up for a short time, enough for me to test it out.
Prototype internals of the project blaster
the blaster with both side of the shell closed, motor covers, and a makeshift power source
After closing it up, and wiring it up to a makeshift power source, it was finally time to test it out!
watch the video below!
While the blaster is capable of firing darts and served as a proof of concept that it would work with enough design thinking and brainstorming, it is currently not practical for use in a game due to many reasons.
1) Lack of a proper power source
This means that the blaster is severely underpowered and the clunky taped-together power source makes the entire blaster very clumsy.
2) It's not finalized
For obvious reasons, you don't bring a prototype design at the initial stages to the field to test it out, especially at the current state of the project
3) More tweaking is required
The blaster still faces a lot of issues from time to time, such as the flywheels not staying in place or the motors shifting around.
So now, while the prototype is completed, further improvement is needed in order to turn the blaster into a capable blaster worthy of seeing Nerf games.
It has been an overall fun project, and I already have people messaging me on facebook, asking me to built this for them or if I will be making a kit for the blaster. sadly I had to turn them all down as I can't possibly bring myself to give them an incomplete project.
Till next time,
Flechette Spectre
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