Introduction: How to Build an Airsoft Trip Mine.

Picture of How to Build an Airsoft Trip Mine.

The airsoft land mine that I bought was a pitiful waste of $50. The self proclaimed "loud boom followed by a large blast of powder" was a tiny pop and half inch high puff. Enemies didn't even notice that they triggered it. Frustrated, I built a better, more powerful mine. It's easy to replicate and simple to use. It shoots BBs twenty-eight (28) feet and powder six (6).

Step 1: Materials.

Picture of Materials.
This project is fairly inexpensive, depending on the materials you already have. I only had to buy the springs.

You will need:
  • 1 inch diameter pipe.
  • 3/4 inch diameter wooden dowel.
  • 3/4 inch diameter washer.
  • 3/4 inch diameter spring (ID # C-756).
  • Screws, 1/4 inch diameter.
  • Fishing line.
  • Smaller dowel.
  • Small metal dowel.
  • Suitable safety pin wire.

Step 2: Cut to Length.

Picture of Cut to Length.

Cut your pipe to lengths of 61/4 inches, or about 21/2 inches longer than your spring. Cut your 3/4 inch diameter wooden dowel into 3/4 inch length plugs. You will use two of these plugs.

Step 3: Build the Mechanism.

Picture of Build the Mechanism.

This is the heart of the trip mine. The device acts like a piston, the spring is compressed and held in place by the pin. When released it springs back, inertia causing the contents to fly out.

First you need to drill a 1/8 inch guide hole through the center of both your plugs. Use a clamp to hold the plug in place. Now for the tricky part. Place your 3/4 inch washer over the base of your spring and line it up with the plug, try to make it as flush as possible. Tightly screw the washer and spring in place, you can do this through the side of the spring. Repeat this for both ends of your spring.

Step 4: Safety Pin Hole and Securing the Mechanism.

Picture of Safety Pin Hole and Securing the Mechanism.

Stand the pipe upright and drop your mechanism inside. Push down the mechanism as far as possible with your smaller dowel (the plunger). Keep your thumb on the dowel where it meets the end of the pipe. Remove the plunger, keeping your thumb on the spot, and place alongside the pipe. Mark where the end of the plunger is, this is where the compressed mechanism will end. Remove the mechanism from the pipe so it does not get in the way of the drill bit. Drill a hole with a diameter equal to the safety pin through both sides of the pipe, slightly above your mark. This will account for any error.
. Reinsert the mechanism, making sure it slides smoothly. Make sure that the base plug is flush with the bottom of the pipe. Drill a guide hole through both sides of the pipe and plug, roughly 3/16 inch from the bottom. Secure the mechanism with a screw on both sides of the pipe.

Step 5: Finishing Touches.

Picture of Finishing Touches.

Search the house for an appropriate safety pin. I was lucky enough to find these beauties. Cut the pin to length with wire cutters. It should pass through the pipe with about 1/4 inch to spare.

Epoxy a 71/2 inch metal dowel slightly below the pin hole. This serves as a stake, allowing the trip mine to be secured to the ground.

Use another small wooden dowel for the tripwire's stake. Whittle one end to a point and split the other end. The tripwire will be fastened to the split. Tie the other end of the tripwire to the safety pin.

You can spray paint the trip mine to blend in with it's surroundings. I did a base coat of black and misted light green over it. The prototype is a base paint of green with a mist of black. I used some ghillie left over from my ghillie suit to further camouflage it. You can also attach local flora with a black rubber band.

Step 6: Operation.

Picture of Operation.
As I said, this is basically a piston. It uses inertia to fling it's contents out of the pipe. Plant the trip mine at roughly a forty-five degree angle. String out the tripwire and plant the stake on the opposite side of the path. Push the mechanism down with the plunger and insert the pin. Make sure as little of the pin as possible is holding the plug in place. Then pour the appropriate amount of BBs and powder into the trip mine.

View the video below to see the trip mine in action. YouTube's quality is horrible, I'm using Metacafe instead.

This is the detonation of the trip mine at 1200 frames per second:

Step 7: Measurements.

Picture of Measurements.

This land mine shoots baking soda an average of six feet with one spoonful, but the powder effect isn't as impressive. I find that two spoonfuls is a good balance between distance and powder effect. Three spoonfuls would be good at close quarters, it will cover you with powder. You're victim won't know what hit him.
You can pour a good amount of BBs into this, I'd say about twenty or thirty. These average twenty-eight feet. Combine BB's and powder for the best effect.


trapshooter4god (author)2015-12-23

im a big airsofter and in making a new corse and I needed some traps and I think I just found one

Kablamo99 (author)2014-11-30

I'm thinking of putting one on each side of the path so they get hit on both sides. I love it and I'm gonna make them.

mikevanin (author)2014-06-18

I don't know how I landed here - but seeing as I did ... I suggest that you could file a generously-sized notch into the edge of each washer, big enough for the spring wire to clear. (Make the edges of the notch nice and smooth to avoid stress cracking the spring (sorry, my engineering discipline insists on being heard, LOL)).

This should facilitate the task of locating the spring reliably.

Himers (author)2013-11-18

Well done!!!

35Timmy (author)2012-04-15

why don't people just have the airsoft tripmines so that they cannot step over it,or even have a fisherman with a fishing rod to angle it in and make it seem so that they cannot escape

zelback1 (author)35Timmy2013-10-27

Funny guy. No sane person would want to stand still with a fishing rod while there are people shooting at them! haha

airsoftmaster191 (author)2008-08-17

nice vidio. i know it was all acting. and wheres the mouth peice?

Mouth piece?

ya. to protect the mouth so you dont swallow the airsoft ammo

You only really need eye protection. I wear my full faced ghillie mask, but I know people who go into the battlefield with goggles or aviators.

zelback1 (author)Spl1nt3rC3ll2013-10-27

I happen to know a guy who would disagree very strongly with that statement. One of his front teeth got broken off at the gumline by a 500 fps sniper from 30 yards away. Its better to have something. Even if its just a bandanna tied over your mouth.

Mouthpiece really isnt needed, just eye protection, besides, i would keep my mouth shut if i was getting peppered by bbs

ilnicki (author)2013-10-15

Great idea.
Will test build a version and if it works out I will mass produce them for our next Airsoft event

Ojsmudge (author)2012-08-14

im gonna make 2 of these but using a confetti cannon things which operate in the same way with springs :)

35Timmy (author)2012-04-15

it's stronger usage advised to first off use invisable fishing line, second to use camo on the trap like a ghillie suit then have a pulling handle for when playing with strong people that could snap the fishing line and to not use the drill unless you are bolting it on,this is what from what i could see happening

35Timmy (author)2012-04-15

if your drilling a hole then why not bolt on a spring instead of screwing cuz when your screwing in if theres a hole then it's not as strong but harder to screw in

35Timmy (author)2012-04-15

how about a more exact awnser how about measuring the compressed height of it being standing up of the mechnisim before it's secured then on the same measurement mark where the pin should be

35Timmy (author)2012-04-14

where did you buy the spring at?

Burnsides (author)2012-03-28

Absolutely had to try this, your design is amazing. Works like a charm.

tpatten (author)2012-03-21

awesome design and easy to make

Aron313 (author)2012-01-09

Sorry but thats dumb. Make something explode!!!!!!

pyro man (author)2009-06-24

what fps would you estimate the bbs to come out at?

rssdeltaforce64 (author)pyro man2010-12-16

probably aroun50fps

daetol (author)rssdeltaforce642011-01-14

50? thats way low thats about 37 mph

KnexFreak360 (author)daetol2011-12-03

If its any faster itll go to high and not hit the target

kve23 (author)daetol2011-02-15

its launching more than one bb and its operated by spring but i know what ur thinking. some airsoft guns are spring powered. buuut those spring compress air to launch the bb its not forced by the spring the bb that is

ilpug (author)kve232011-08-17

it doesent have to be very fast, just enough to get them out there.

pirate of doom (author)2009-06-08

my buddy and i shot each other with air soft shotty (homemade pneumatic around 120 psi.) from like 30 -40 feet. the carnage resembled a be swarm.

ilpug (author)pirate of doom2011-08-17

that was a really dangerous thing to do. you are lucky none of the ammo penetrated.

UNKN()WN (author)2010-08-17

this is pretty cool, but i cant find that type of safety pin

ilpug (author)UNKN()WN2011-08-17

just use any kind of wire or rod strong enough to hold back the spring

ilpug (author)2011-08-17

nicely done, cant beleive i didnt check out this ible more closely. i must do this.

mechaninja (author)2011-08-08

I think your "pins" are pegs for a pegboard, like in a toolroom.

master mad (author)2011-06-01

Let me guess, you bought the land mine from airsoft GI right?

yusuf786 (author)2010-04-17

hey nice instructable !  how can i know what is *bb* ?? is the bomb or the ammo ??

1spartan95 (author)yusuf7862010-05-12

BBs are small balls shot by airsoft guns. BB stands for Ball Bearing.

Actually, it doesn't. It's reffering to a size of shot originally used in shotguns...There is also "B" and "BBB" sized shot...

Wikipedia-BB guns are a type of air gun designed to shoot projectiles named BBs after the birdshot pellet of approximately the same size. These projectiles are usually spherical but can also be pointed; those are usually used for bird hunting. Modern day BB guns usually have a smoothbore barrel, with a bore diameter and caliber of 0.177 inches (4.5 mm). BB for modern day BB guns are usually steel, plated either with zinc or copper to resist corrosion, and measure 0.171 to 0.173 inches (4.34 mm to 4.39 mm) in diameter. Some manufacturers also still make lead balls of slightly larger diameter and which are generally intended for use in rifled BB gun barrels, as were formerly used in BB guns.

(Found under the BB gun entry)

yusuf786 (author)1spartan952010-05-15

Thanks SparTa ! :)

BlackOps123 (author)2011-05-03

Is it a multiple use mine?

Bam2169 (author)2011-05-01

I got to say it worked pretty good but I made mine out of metal tubing and a screw in cap so If anything breaks I can open it easy to fix it I also have a second ca so that If I prepare them (I made a few :P) before a game All I have to do is remove the top cap and if it went of by accident I dont get hit :P

Landon Sullivan (author)2008-07-31

I've seen that M4 somewhere before... I think it was at Fry's. It was $79.99, if I have the right gun. Just saying.

That gun was a terrible waste of $80. Stunt Studios SS2. It's cumbersome and broken. The "grenade launcher" (which turned out to be a pump action, shooting one lousy BB at a time. Not the Co2 shell loaded one I was expecting.) jammed. The gun itself tends to quit on you at the least convenient times (smack dab in the middle of a firefight, for example.). Now I just use my trusty Co2 pistol (which is starting to act up :(.)

gymnast (author)Spl1nt3rC3ll2008-09-15

i bought a aftermath kraken (cyma 0.28 rebrand) and ive had it for a month now and it works like a dream

xACIDITYx (author)gymnast2008-09-22

Yeah, I like my Cyma 028 (I think that's the right model... AK47 is what mine is) anyway, I got it for 100 bucks and it works great.

airsoftbeast40 (author)xACIDITYx2011-04-24

I have the same gun as both of you. i got it from big 5 and have had it for three years now. it amazes because it still works perfect and it outshoots my 200 dollar m4 variant sniper

is that suposed to be a pokemon icon i_am_ninja?

kve23 (author)2011-02-15

about the fourth pic it is safe cuz da saves on

TALLJ29 (author)2011-02-09

Hey i did this yesterday and it turned out awesome! Thank you.

Fizzxwizz (author)2009-07-31

1. Did you self paint that? 2. Is that a high Cap Mag?

Spl1nt3rC3ll (author)Fizzxwizz2009-07-31

1. Yes, I spray painted the trip mine. 2. Is what a high Cap Mag? The mine has no magazine...

About This Instructable




Bio: Avid Geocacher and fan of all things iBles.
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