Introduction: Spring Powered Bow, Simple But POWERFUL!
Today I show you, how to make a simple but powerful bow. Making the limbs out of something flexible is a pain,
even finding good material for it. We just use tough metal and some wood :>
Material / tools:
- Jigsaw
- Drill
- soldering iron, laser module, Li button cell, solder and 2 pieces of wire (optional)
- M5 screws and nuts (or similar)
- 2 STRONG (!) tension springs (mine are 40kg /75lbs)
- Bow string (I used 48 inches long string found on ebay for 5 bucks)
- Short pieces of tubing, 5mm inner diameter at least, 15-20mm long
Step 1: The Grip, Made From an Old Shelf
You need a saw and a drill (5mm if you, like me, use M5 srews and nuts). Print out the template, make sure its around 270mm long) and glue it on the plank, then cut it out, file the edges, sand em, and we are ready to move on.
Step 2: The Limbs
4 identical (nobody said it needs to be PERFECT though) pieces of Aluminum, 4-5mm thick.
Cut out, add a tubing in the middle to keep the right distance. Length depends on the thickness of
your wood (gnihi).
Make sure there is a tubing at the tips, attaching the string to a threaded rod / screw won't work for long,
so cover it with.
Step 3: Reinforcement-plates
Cut out 4 of them, the outlines match the outlines of the grip. 2 holes through one of them,
put it on your grip, mark the holes, drill through and don't forget the springs. Repeat, and off to the next step!
Next and last step is the bow string. I attached it to one end, across the tips and back into the limb,
where I drilled an additional hole (2 holes), to make sure there is a basic tension on the bow.
Step 4: Instructional Video
Showing most of the steps, not in detail, because it really depends on your springs.
Now go for it, its worth the time and effort ^^

Participated in the
Rainy Day Challenge
23 Comments
Question 1 year ago on Introduction
where can I buy these springs
2 years ago
Do you think It would be likley to break if the arms were made from 2MM aluminium?
If I had Stronger springs would I need to make the arms longer?
5 years ago
Do you think that a better version of the bow you made is approved in the competitions?
I have an other question, how many lbs your bow can manage when you want to shoot and at how many lbs a bow like this can arrive if built even better?
Reply 5 years ago
I will make a sturdier version, this was just made of left overs.
Reply 5 years ago
when will you make it?
5 years ago
is it capable for hunting?
5 years ago
i don't care what anyone says. that thing is cool as hell
Reply 5 years ago
soon as I find a couple of springs that are identical I'm making one
5 years ago
I am planning to build a bow the next month. But I don't know if a bow powered by springs is approved during the competitions. I want to build a really really powerful bow and to now the lbs of yours may be interesting. Can you build the next version before the end of June? It'll be amazing.
Reply 5 years ago
You know how to do it now, go for it. How much force depends on how much you can pull I would say. Try it out.
6 years ago
Hey man could i make a crossbow wit same design? I mean is it possible?
Reply 6 years ago
I will. In combination with a video showing the lock/trigger mechanism.
Reply 6 years ago
I found a video from some Russian guy, i mean it is very simple have a look:
https://www.youtube.com/watch?v=DRRDGInyy8A
6 years ago
Kommt auf die Feder und die Sehne an. Hab meine bei ebay geholt, 48" lang. Je länger die Arme, desto weniger Kraft zum Spannen.
6 years ago
wie lange sind deine limbs und deine Reinforcement-plates?
Reply 6 years ago
Pass die einfach an den Griff und die Federn an. 2 Schrauben durch und feddsch.
Reply 6 years ago
Also die Limbs fast so Lang wie der Griff?
Reply 6 years ago
Zu kurz.
6 years ago
Looks cool, compared to a classic bow is it easier to shoot?
Reply 6 years ago
Hm, not really. Depends on the springs. The secret is, a long lever. So make the limbs long, mounting hole close to one end, and springs to the VERY end :> that way you dont have to crank them with too much force. My limbs are kinda short, because they are leftovers, the sketches show longer limbs.