Slingshot Rifle Tutorial
Slingshot rifle, Catapult rifle or slingshot crossbow: Device powered by rubber bands capable of shooting spherical ammo (lead, steel, mud) and darts.
Precautions!!
Use the necessary safety equipment when buliding this and always wear safety glasses when shooting. The ammo may ricochet from hard surfaces.
Please handle with care.
Supplies
For the stock I used 2m (6feet) of 2 by 4 (~4cm by ~8cm) but you can use whatever you have laying around in your workshop (like a 2by10 even if you're going have a lot of waste).
You'll need a trigger device, I really recommend this one (https://it.aliexpress.com/item/1005004077939955.html) on AliExpress you can find it on amazon or ebay too by searching slingshot trigger.
Rubber bands flat or tubes with pouch and everything.
Screws and bolts to attach everything to the stock.
Wood glue
Depending on the fork you may need some metal plates.
Tools
Drill,
Screwdriver
Files and rasps
Sandpaper (various grits)
Chisels
A saw to cut out the shape of the stock (a jigsaw/bandsaw is great but you can do it with a handsaw)
Square, tape measure and pencil for marking.
(it should be everything)
Deciding the Shape
Here you can use your fantasy and chose your favourite stock or maybe draw a custom one tailored for you.
There are a couple of details that you have to consider: overall length and the cross-section.
The length is important as it will affect the shape(of course), the draw-length(how far back you have to pull the rubber-bands) and the draw-weight(how hard it will be to pull them back). I usually go with 1m (a bit more than 3 feet)
The cross-section is as important if not more as it has to substain (without breaking) the force of the rubber bands. I like to keep the same cross-section of a 2by2 but a good measure is if you can bend it in any way. If it passes the test it shoud be good enough.
Just a quick tip chose the right Lenght of Pull (distance between trigger and buttstock) for yourself as it greatly affects the comfort. The L.O.P. varies a lot with an average of 13.5" (33-37cm).
Tracing the Template on the Wood
After deciding the shape that you want it's time to trace it down, you can try free-styling it or you can use a paper template or whatever you feel necessary. I went with this design and i tried to save as much wood as possible using scraps and other pieces.
Gluing the Stock
You can skip this passage if you have a big enough slab for your tastes anyway I highly suggest that you use at least a 2by2 glued on a 2by4 like I showed you in the pictures. This are the pictures of the gluing process as i had to do it in steps because i don't have enough "clamping power".
Cutting and Carving
I'll be quick on this step as im going to attach not one but 2 or 3 tutorials on how to carve out your rifle stock.
Just don't carve any kind of inletting or stuff like that, I'll guide you through it.
Tutorial 1
https://www.instructables.com/Building-a-Custom-Rifle-Stock/
Tutorial 2
https://www.youtube.com/watch?v=A54xUpM8bUI&list=LL&index=7
Tutorial 3
https://www.youtube.com/watch?v=XR-Dr5kLe-8
Inletting the Trigger
After having carved most of the stock it's time to make space for the trigger mechanism. This step is way easier with the trigger at hand. You may or may not chisel out the slot for the trigger but it's obviusly necessary to "dig" the channel for the lever (around 6mm wide and 20mm long).
Sanding
Smoothing and sanding. Here a sander is very helpfu as it's the most boring part. I started with 60 grit to 120 to 180 and i finished with 400.
Fork and Bands
The last part that we have to bulid is the fork and the bands, there are lots of tutorials on this topic so this is another step where you can experiment and find what works best for you.
this is one of my favourite forks of the bunch
https://www.youtube.com/watch?v=lDBnYT9gXzA&list=PLb5nuGxFHq3_qX4Awd5_Khzk3Od8FDwOm
https://www.instructables.com/Easy-Build-Heavy-Duty-Slingshot/
Alternative Triggers
If you don't want to spend money on a specific trigger you can try to bulid your own. Here are some tutorials.
https://www.youtube.com/watch?v=V4joFz6Xbkc&list=PLF_2oAEL2VMldlVVxGIj4D5ap-d8Tm16t
i suggest avoiding "crossbow" triggers as they are too complicated and they don't bring any advantage.
This is my favourite trigger design.
https://www.youtube.com/watch?v=lDBnYT9gXzA&list=PLb5nuGxFHq3_qX4Awd5_Khzk3Od8FDwOm
Further Modifications
You now have a working Slingshot Rifle. If you want to add gadgets of any kind you can add some picatinny rail (3d printed or bought) and customize it even further. I'll link a forum thread that gives you more details on wat to add and how to do it.
https://www.slingshotforum.com/threads/setting-up-maintaining-and-enhancing-the-slingshot-rifle.127680/#post-1468000