My 3D printed electromagnetic BB gun

[rpopeye]

It's entirely 3D printed, took me about a year to design and build on my Turnigy Fabrikator.
Because the size of the printing area 15x15x10 cm of my Fabrikator is much smaller than the size of the whole thing, I had to glue together the different parts, which in this case was quite challenging, because very tight straightness tolerance was required. To achieve this I used an aluminum beam as reference.
The finished electromagnetic BB gun looks not only cool, but it's also fully functional and basically as good as a normal CO2 powered BB gun.
https://youtu.be/jhtAsYy7dgM
IMG_4982_small.JPG

[Roxy]

Very cool!

[Roberts_Clif]

I would like to know more about this electromagnetic BB gun.

[Roxy]

Yeah... I would like to see the circuit and how the BB's automatically feed into the accelerator.

I would like to see a tear down of it...

[ethompson]

Very impressive...

[rpopeye]

Thanks, guys, much appreciated!
The electronics circuit is pretty standard - a series of coils along the barrel are switched on and off in succession, which attracts and accelerates the steel BB.
Every coil is controlled by the circuit below. The control signals for each coil circuit are generated from an MCU. The coils are powered from a high voltage capacitor bank, which in turn is charged up from a battery by means of a boost DC-DC converter. The BBs are loaded by a standard servo with a disk attached to its horn. The servo first turns to 0 degrees to get the BB from the top of the clip, then turns to 180 degrees and positions the BB right in front of the barrel - hence the servo noise between shots.
circuit.jpg

[curious aardvark]

very neat.
Could you make it smaller ?

[rpopeye]

yes, it is possible, the bulk of the size comes from the capacitor bank, by tweaking the electronics and reducing the size of the capacitor bank it would be possible to reduce the total size, but not much, perhaps 20-30% at most. To reduce the size further will require some radical changes in the electronics to compensate for the reduced energy in the capacitor bank.

[rpopeye]

Here is a picture of the interior, the rest of the volume is pretty much filled with capacitors
IMG_4587_small.jpg

[1337llama]

That's Awesome!