Heavy Crossbow




About: I like playing "Jump over the fence and scare little kids".

This is a guide helping you to make a heavy crossbow capable of killing a person.
NOTE: this is capable of killing most things except big game, so DO NOT attempt to shoot anyone or anything without thinking of killing it, and if you do, I am most definatley not responsible for the death or injury so be-friggan-ware.

Also note that the crossbow should be made over a span of 2 days, the second day can be spent assessing the crossbow, tweaking it and adding features.

Step 1: Materials

Before you start you will need these tools:

-Ratchet saw (that motorized hand saw thing)
Note: if you do not have this you will be sore from cutting the wood out with your hands, so yeah, this tool helps.
-Coping saw (any saw will do)
-Vice (absolutely, positively needed)
-Carving tool (last picture), fairly useful, if you can get one.
-Drill pieces
Note: I have gone into detail, just in case some idiot complains about it.

Deadly Resources required:
-Wood (1 metre length and 15 cm width, which is about 3 feet length and 6" width, I think).
-wooden blinds
-String (strong, the thicker the better)
Note: Wooden blinds can be substituted for bamboo, I will go into more detail in step 3.

Step 2: Marking and Chopping Wood.

The chunk on the third and first picture has to be kept.
Chop the wood with the Ratchet, make sure that the wood is in the vice or you will be missing a few fingers after this step.
The chunk taken out of the body should be kept unless you have scrap wood lying around.

The chunk of wood that has been chopped off you should now put into your vice look at picture 6 to see where the screws go, drill them in slightly so the're in there but not completely through the wood, now remove it from the vice and clamp the base there, then fully screw in the chunk as shown in picture 5. This is the stock.

Step 3: The Bow

The bow really does vary, any material that is bendy but not in the mood to snap will do, but here are some rules.

1. If it is too bendy, add more of that and increase distance of shooting slide (cock).
2.Add 3 or four of the blinds shown (Best option).
3.Bamboo is the worst option for this crossbow but still efficient, I did manage to make a crossbow that didn't snap with a bamboo 2 metre pole, but the blinds are the best option, although I don't know where to buy them from.

If your using the blinds drill a small hole on the ends of the blinds (pic 3+4) tie a knot at the end of the string after threaded through, then thread through the next hole on the other side (make sure string is on the right side of the wood and not twisted or knotted) wrap the string around numerous times then tie a normal knot, then double it, maybe triple. Pull the bow back to the end of the cock, if it feels too tight its about to snap, loosen the string, if its too weak, tighten it.

E-mail me if you're using something else.

Step 4: Inserting Bow and Making the Cock.

The bow will go up in shown area of that chunk missing, so stick it in there and get either scrap wood or cut the chunk kept to size and hammer it in with the mallet, if the bow is moving too much get a different piece of wood and try that with the mallet, make sure it doesn't move.

The groove in the cock is made with the carver so rule 2 straight lines parallel to eachother same width of the carver and carve in a chisel like fashion along the length of the cock (pic 2).

Step 5: Trigger, Sanding and Firing.

You'll notice a fair few rough edges, eliminate them with sandpaper.

The trigger is really simple and capable of holding a massive amount of power, look at picture 1, now the way to do it, saw a 1 cm slit at the end of the cock grab the chisel and mallet, chisel either an angled cut or horizontal depending on where you want the trigger to be.

To fire, flick your thumb up below the string when loaded with an arrow or bolt, it should fire, if not look at the crossbow have a think on where it went wrong.

And if you're really impatient and want a less accurate and easy thing to shoot, get some large bullet-head nails.

Step 6: Regards...

If you have any questions relating to your crossbow, it doesn't even have to be my one here, e-mail me at sutherite@hotmail.com, set your subject to crossbow otherwise I will most likely delete it.

And for safety, do not shoot this at anyone or thing otherwise you will trigger a slight neurological disorder called DEATH, and if you're wondering how or what to shoot and you don't have professional bolts or arrows I will be making a guide for those some time soon.

And also If you're crossbow can shoot over 100 metres (over 270 feet, I presume) e-mail me on what you used, because you are successful, if it doesnt shoot far e-mail me anyway and tell me what you used so I can help.



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    53 Discussions


    5 years ago on Introduction

    aewsome. I'm doing a crossbow like this here in Brazil. here is completely legal


    5 years ago on Introduction

    Cool! Too bad it's prohibited to make or own a crossbow in Norway. I really want to make one.


    6 years ago on Step 3

    You need to use the BRANCHES to make a bow out of bamboo. Needless to say you would need a bamboo plant far larger than any you are likely to have in order to get sufficiently large branches. Bamboo is actually one of the best bow materials in existence, even surpassing yew or composites.


    7 years ago on Introduction

    I would make a straight 1/2" groove along were the arrow goes. This would make it shoot more often, and shott more accuratley.

    no offense but the picture just makes it look bad you should take a ppicture with it painted or something


    7 years ago on Introduction

    For a simple trigger mechanism look at the shelf latch styles at http://scamelee.freeservers.com/combat_crossbows.html (or search for Fellwalker crossbow) , I have a crossbow I bought used a few years ago that seems to be a shelf latch that uses a metal lever to push up a spring loaded wooden peg to release the string. For very heavy draw weights the roller nut style release seems to be hard to beat for simple reliability.


    7 years ago on Step 6

    Roughly speaking, 1 metre is 3 1/3 feet (3 feet, 4 inches).

    Using the converter on my phone, 100 metres comes out at a fraction over 328 feet (328.083984 feet, if you want to be pedantic ;-) - and if you really want to be geekily pedantic, that '0.083984' of a foot is 1.007760 inch ;-$).

    1 reply

    try to add a trigger mech with a lever that pushes the bowstring up attached to a gun style pull triggger. Happy building :)


    8 years ago on Introduction

    i used pcv pipe i cut them in half lengthwise then stacked them open end to closed end then fixed then together using rubber bands, i used about 2 pipes and it is powerful my first string broke after a few tries

     It's gonna be hard to use the trigger when you have a strong bow. Maybe, adding a lever somewhere will ease triggering. Then, cocking it is another story... 

    Besides, laminate a piece of bamboo and you've got something new to play with! I remember my old homemade crossbow sitting in a box. I can't even cock it; the bow is just two pieces of bamboo laminated together. Sounds like another instructable heading my way...

    Hey, most find me strange or crazy because im a bit of a redneck :D I always tinker and build weapons. This is AWSOME! This is next on my build list, I'm also working on a coil gun.... but thats a bit more complex :) Thanks for the ibl.


    8 years ago on Introduction

    good instrucs and a nice xbow, i made one 2 but yours is simpeler but mine shoots further but is more dangerous :P its stil in the prototype fase. should i post it on instructables?
    ps. your trigger is a bit hard to shoot if your bow is strong


    Reply 9 years ago on Introduction

    when the bolt got lodged in my fence, i pretended that was someones face, oh and pretty much anything can kill, like you could probably die by a fork so that can apply to toys with small parts as well.


    9 years ago on Introduction

    From what I can see, there doesn't seem to be any grove or slit cut to hold the bolt/arrow.