Pocket Sized Spring Loaded Dart




This is my first instructable, so any feedback (positive or negative) will be welcomed.
This is a spring loaded dart made of common items found in my local hardware store. My son and I saw something similar to this on a National Geographic special about the Chinese weapons. I don't remember what they actually called it, but from what I remember it was considered to be an assassin weapon. A low powered spring loaded dart that was typically dipped in poison. The weapon was easily concealed, and powerful enough to break the skin which in turn administered the poison. My version will shoot about 35 feet. I imagine that if I put a tip on the dart it would travel further due to aerodynamics.

Step 1: Material and Tools

Everything I used to build this was found at my local hardware store.

Parts Lists:

1 - Shut off valve with chrome sleeve
1 - Short length of 1/2" copper tubing (2-3/4" long)
1 - 1/2" copper cap
1 - Strike plate
1 - Washer #10 I think
2 - Set screws 6-32 thread 1/8" long
1 - Length of aluminum solid tube 1/4" diameter
2 - Springs (#11 at my hardware store)
2 - Bronze bushing (5/8"O.D. 1/2" I.D.)
2 - Bronze bushing (1/2"O.D. 3/8" I.D.) Not pictured sorry
2 - Bronze bushing (3/8"O.D. 1/4" I.D.)
1 - tube of Locktite


Solder iron
pipe cutter
Various files
Allen wrench

Step 2: Construction Begins

First I used the pipe cutter to remove 4-1/4" of the chrome tube from the shut off valve.
Then I took the bronze bearings and slid them inside each other to make 1 long bearing with 5/8" O.D. and 1/4" I.D. I slid this bearing inside the chrome tube and soldered in place at the end of the tube.

Step 3: Working on the Copper Tubing

Take a piece of 1/2" hard copper tubing and using a pipe cutter cut it down to 2-3/4" long.
Solder on 1/2" copper cap to one end of the tubing.
slide copper tubing into the Chrome sleeve and tape it in place.
Drill a small hole 1/4" from the edge of the chrome sleeve going through both side of the chrome sleeve and the copper tubing.
Remove the copper tube from the chrome sleeve, and set the chrome sleeve to the side.
Using a dremel I cut an L shaped groove on both sides of the copper tubing.
The groove is 1-7/8" long with a 1/4" leg (Which creates the L shape) cut towards the where the cap is located. Then I filed the grooves smooth.

Step 4: More Work on the Chrom Tube

1-Tap the two hole just drilled into the chrome tube with a 6-32 threaded tap. Once the set screws are in place, the copper tube will slide in and out of the chrome tube as if it were on a track. the screws also prevent the copper tube from completely sliding out of the chrome tube.

2- On the opposite end of th chrome tube where the bronze bearings are drill a 1/16" hole through the chrome sleve 1/2" from the edge. Then I used a dremel to wide the wide the hole. The overall dimensions of the hole are 1/8" X 3/8". This hole will be used for the triger assembly.

Step 5: Trigger Assembly

The trigger assembly was originally made out of a copper strap hanger which you can see in the picture. The only picture of the final trigger is an installed on, but the old one shows the concept of how it works. I cut the trigger assembly out of a brass strike plate with a dremel, and then hand filed to the desired shape. Can you tell I like my dremel? The larger hole is 1/4" in diameter, and the smaller hole is 5/32" in diameter. The strike plate already had a curve end which I made the top of the trigger. I pushed it through the chrome sleeve, loaded a dart, locked it in place, and then bent the bottom of the trigger to lock it in place( I beat it with a hammer).

Step 6: The Springs

I wanted the springs 3" long so that when the brass tube closes into the chrome sleeve the spring will apply force against the bronze tube. Thus locking the copper tube into place by binding it against the set screws when turned into the leg of the L groove.

I kept 1 spring full length and I cut one down to make the total of 3".
On the full length spring I soldered on a Flat washer and a little piece of metal to fill the hole in the washer. I placed the springs into the copper tube, and then inserted it into the chrome sleeve. Once the copper tube was inserted into the sleeve I locked into place with the set set screws. I used locktite to prevent them the set screws form backing out.

Step 7: The Bolt

The bolt is a piece of aluminum 1/4" diameter and 2-7/8" long.
I used the dremel to cut a 1/16" groove into the bolt. the groove was cut 1/2" back from the front of the bolt. I chose not to put a point onto the bolt for safety reasons, but it could easily be done.

Step 8: How to Load and Fire

1 - Pull bass tube out of chrome sleeve.
2 - Put the bolt into the chrome sleve.
3 - Once the bolt is in the chrome sleeve lock it into place with the trigger assembly.
4 - Push the copper tube back into the chrome sleeve and turn it to lock it into place against the set screws.
5 - Point it away from people and animals.
6 - Push down on the trigger and watch the bolt fly.
No... Seriously watch it fly. My son and I spent 30 minutes looking for a bolt because we didn't see where it landed.

This is potentially dangerous; please use caution if you decide to build one of these. I am not liable for any injuries or accidents that may as a result of building one.



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    32 Discussions


    2 years ago

    This is actually pretty amazing, and I enjoyed reading every step. I actually bought a Chinese Sleeve Arrow (thats what i think it's called), and this 'ible helped me figure out how ut works and helps me if I decide to make a copy if the one I bought


    5 years ago on Introduction

    Wow! This is a cool twist! Way better than those dumb paper launchers and stick shooters. You should make an 'ible about making an ammo kit for this out of a tin our something so that people can use it in a survival situation.


    8 years ago on Step 6

    does the screw hit the spring?

    i cannot believe that nobody else has commented on this, it is such a well designed and thought out piece, it is somewhat reminiscent of some of the more dangerous zip guns, which require bullets to fire. I am planning to make an instructable on a small steel crossbow soon, if I do, i will definitely include a link to this i'ble, because I think that it is highly unjustified that this has received less views than other really basic, boring weapons, like the ten thousand "skewer launching" items that even the average ten year old could make without any instructions. 5/5 please make more instructables, you obviously have a very comprehensive understanding of the technical side of things (and some awesome dremel skills) keep up the good work LG oh also, you are my first subscription

    4 replies

    Thank you so much. I haven't even seen my instructable posted on the main site yet. I've been looking everyday for almost 2 weeks. How did you find it?


    Reply 8 years ago on Introduction

    look at page 76 on offbeat thats one place though i stummbled across it on a search to


    8 years ago on Introduction

    this is great right now i am working on one of these out of pens and house hold materials

    1 reply

    Reply 8 years ago on Introduction

    so in the end i could not get any pens to fit over top of each other and fit my spring but i have started making one of scrap steel from behind our shop and so far i have the spring and the tubing for the spring ready i found that i did not need a end cap i just cut a cross into the pipe and bent the sides down it worked really well


    8 years ago on Step 8

    Thanks so much for the instructable. I finally was able to build mine. I changed it so instead of using a steel pipe i used another copper one. it gave it more of an "old" feeling to it. Great Instructions!


    9 years ago on Step 8

    I've never made a video before, but I guess there's a 1st time for everything. I'll work on it this week.


    9 years ago on Step 8

     where do you get the shut off valve? I have looked everywhere for it. If you could help me out that would be great.

    1 reply

    Reply 9 years ago on Step 8

    My local hardware store sells them, but you can also get them at any plumbing supply house. I hope this helps. If not let me know and I will try to locate 1 for you.

    so...this is sorta like a ballistic knife! this is awesome i am going totally make one! ya i have built several ballistic knives so i guess it is the same concept!


    Reply 9 years ago on Introduction

    I had most of the parts already, but I think if I were to buy them new it would be around $20 to $30.


    9 years ago on Introduction

    you could increas its aro dynamics by super glueing a rubber tip in the end its an ok idea hope it helps


    9 years ago on Introduction

    WOW! I CANNOT believe this has so little comments! It is so cool! I am going to make one right now!!!!!