Solenoid-based Nerf Blaster - help?

[Stoph]

Hello, first time poster, huge Nerf enthusiast.

Hoping for some help with a concept, my grasp on electrical engineering is tenuous at best.

I want to turn a Nerf plunger tube into a solenoid, by way of wrapping it in wire, and running a charge through it. I'd machine a free-floating, steel-faced plunger head, to interact with the coil, and attach a weak extension spring to the back half of the plunger head to allow for it to return to normal.

The plunger tube is around 1-inch in diameter. Would a solenoid this size be viable? The hope is for a fast linear action without springs or pressurized air, that uses few moving parts, is compact, and enables a semi-auto/full-auto cycle.

Thoughts? Willing to do the hard yards in machining, just need to know if it's a viable idea at this point.

Thanks in advance!
- Stoph

edit: drew a very crude diagram of what I was thinking, hope it helps!

key: orange part is the coil, green part is the steel face

 

[meBigGuy]

read the wikipedia page on coil gun.

Also, read about linear motors and linear actuators and see what works for you.

 

[Stoph]

Thanks, think linear motors and actuators aren't gonna cut it cause they move too slowly to make it worth my while. In my travels I discovered the wonders of neodymium, so I may change route altogether.. Thanks again!

 

[berkeman]

It would be more practical to use a screw drive to pull back the plunger against a spring to load it up, then have a release mechanism to lauch the nerf ball...

 

[Stoph]

Screw drives would be a powerful, yet slow alternative to priming. I'm attempting a spring-free design, so to increase rate of fire and reduce stress on otherwise flimsy plastic. Thanks for the suggestion though!

 

[berkeman]

Maybe make a spinning wheel thingie with multiple arms and a nerf ball cup on the end of each... shaped like those hand-held dog tennis ball throwers. The thrower is hand-held, not the dog... :tongue2:

 

[Stoph]

Haha that sounds fun! Sorry I didn't make it entirely clear - I'm truly only interested in alternate means to produce fast linear motion in a plunger tube, in order to fire Nerf darts. The hope is to be able to retrofit most pre-existing blasters with this system and herald a new approach for modders in the Nerf community.

 

[meBigGuy]

Did you read about the coil gun at wikipedia? That is essentially what you want to do, only accelerate a piston as opposed to a projectile. You could use magnets to drive the piston. Don't discount what you can learn from wikipedias linear motor page. That is what you want to build.

"High-acceleration linear motors have been suggested for a number of uses. They have been considered for use as weapons, since current armour-piercing ammunition tends to consist of small rounds with very high kinetic energy, for which just such motors are suitable. "

 

[Stoph]

Hi mate, yes I've read extensively about coil guns, and whilst it'd be brilliant for my application, I'm more after the viability of retrofitting the existing plunger tubes and internal components of existing Nerf blasters. That also limits the amount of things I can cram into the shells of the blasters, and I'd rather not have to go the route of capacitors and bulky setups. Thanks again for your input!

edit: oh and my response regarding not using linear motors, I was more referring to traditional gear-driven mechanisms. This solenoid design would be closer resembling the coil gun you've referenced.

 

[berkeman]

(BTW, we don't normally allow discussions of coil guns here, but since we are dealing with nerf balls/darts, I'm okay with it as a side discussion so far)

How about... use your electric motor to pressurize a small reservoir, and fire the darts pneumatically...

 

[Stoph]

People have fitted compressors to fill the tanks of air-blasters, so it's not an entirely new thing there. One of my faves, the Nerf Stampede, uses a motor and gears to prime a springed plunger tube and fire darts that way. What I'm trying has not been done before (to my knowledge), whilst a lot of the other "obvious" methods for propulsion have been used in current blasters, or implemented by modders already.