Comments on: Portable coil pistol

By: ChrisW

ChrisW — Sat, 19 Jun 2010 00:47:01 +0000

Here’s a little bit of info for those of you who are worried about the evil of guns and don’t know basic kinetic equations like force, the projectiles will only have 19.6 Joules of force at muzzle velocity. As the projectile travels from the muzzle this will drop off, but as we only have muzzle velocity we can only guess what it will be at 10, 20, etc. meters. For a comparison an average bb is 5 grains (0.0003 kg) and has a muzzle velocity of 800 ft/s (243.84 m/s) for 15.42 Joules of force. Basically this is a bb gun without the penetration of a bb.

Awesome project though!

By: William

William — Sun, 15 Nov 2009 03:13:00 +0000

I think the batteries must be placed in the handle, otherwise I cant see where they would go, except maybe on top…

By: aman

aman — Wed, 29 Jul 2009 07:16:56 +0000

That is a very fine pistol developed from easily available things. Thanks exbi chao.

By: ian begg

ian begg — Thu, 09 Jul 2009 17:47:10 +0000

hi i was wandering if you can email me the instructions or parts list.

By: toojeep4u

toojeep4u — Fri, 19 Jun 2009 12:11:10 +0000

Pretty cool, but that’s a lot of energy drinks!

By: TheKhakinator

TheKhakinator — Wed, 10 Jun 2009 09:56:33 +0000

The internet isn’t for kids. For fuck sake, don’t ruin our fun, vibrators are awesome, as are guns, as is innovative technology.

Hell, out here, Mars are claiming they’re reducing bar size (but not price) to ease things for fat people. Sure it’s really just so their profits go up but honestly, fat people and kids (AND ESPECIALLY FAT KIDS) ruin it for everyone.

By: eggman

eggman — Sun, 31 May 2009 17:23:09 +0000

wouldn’t the weight and friction of the other rounds in the magazine ontop of the one being fired reduce the power significantly?

By: kent

kent — Wed, 27 May 2009 19:50:33 +0000

Video from site:

I think smaller projectiles would help a lot. It would increase the speed of the projectiles, plus you wouldn’t need as large of a charge to move them.

By: Reginald Backster

Reginald Backster — Mon, 11 May 2009 16:09:51 +0000

Oh baby baby
How was I supposed to know
That something wasn’t right, yeah
Oh baby baby
I shouldn’t have let you go
And now you’re outta sight
Show me how you want it to be
Tell me baby cause I nneed to know now
Just because
My lonliness
Is killing me(and I)
I must confess
I still believe(still believe)
When I’m not with you I lose my mind
Give me a sign
Hit me baby one more time

By: Seraph

Seraph — Sun, 10 May 2009 05:26:22 +0000

ive been following rail and coil gun tech for awhile, but havent seen anything new, not like this. apparently its come a long way, if he can get those velocities with that wieght of projectile, and only that amount of power, why the hell isnt he working for the military, theyve been trying to get guns to do that for years, and those all took room sized banks of capacitors

By: Mattster

Mattster — Sat, 09 May 2009 00:38:07 +0000

One useful addition would be the use of a Krytron along with some Supercaps. Krytrons are easy to get as old copiers from years ago can be found and the krytron can be worth at least one good pulse but a few isn’t uncommon before it needs to be replaced.
I used to work with Laser power supplies and typically saw a fresh Krytron worth 50 to 100 starts of a 35 watt laser.
Given a krytron, big caps and a superconducting coil might be fun and dangerous toy.

By: -hero

-hero — Fri, 08 May 2009 21:59:59 +0000

jeez dont try to make it aimable or anything

kikaz tho

-hero

By: Mr. Together

Mr. Together — Fri, 08 May 2009 20:14:48 +0000

Sweet duuuuude

By: ApprenticeWizard

ApprenticeWizard — Fri, 08 May 2009 14:36:04 +0000

@ designer: beautiful build. I look forward to finally seeing whatever documentation you have on it (once the deluge ebbs and your site is again accessible)

@lucas: just a guess (since I haven’t seen the schematic yet), but the light bulb might be a charge indicator (less likely) or being used as a form of variable resistor: originally Wein bridge oscillators used light bulbs in a similar fashion.

@everyone rabbiting on about guns: first point, know what your kids are doing on the internet. Second, if your child has the technical know-how to build one of these, bravo; if they learn what they need to know to build one, bravo; if they build one of these fairly labor- and parts-intensive projects without you knowing, you have other problems. Third, of all the myriad of things I wouldn’t want a child to see from this site, this is fairly low on my list. This will foster knowledge of projectiles, magnetics, and working within design constraints. Other, still fascinating, hacks on this site (e.g. reprogramming electronic construction signs) have little in the way of educational value to a kid, and are far easier to do. Further, the “gun” is a standard footprint, and portability places interesting design challenges on the system.

@designer: did you try different projectile weights? It may be that you can get more kinetic energy overall: Given E_k = 0.5*m*v^2, reducing mass to increase velocity gives a better energy trade-off.

By: grovenstien

grovenstien — Fri, 08 May 2009 14:17:51 +0000

This is what machine screws capacitors and clear acrylic were invented for! Smaller custom poled neodymium magnets for rounds might go faster!