I’ve always fancied developing a miniature trap, I thought it could be a fun toy. I was right, it is. Even if it did take me ages to get right, it was worth it.
Keyring Bear Trap
This miniature keyring bear trap is very easy to build. All cut from 1.5mm scrap steel and a nail. No welds, or soldering just simple bends. In fact you can make it with a small hacksaw and small file at a push. The only special part is a suitable Torsion spring – more on that in a moment.
If you print the free template at the bottom of the page you can either stick it onto the steel, or draw around the templates with a fine tipped marker. As long as you do not undercut the templates everything will be fine. You may find little bits of steel around the jaw or catch may need to be filed away to get it to work. This is intentional. You can always cut or file metal away, you can’t add it on.
And if you mess up an individual part, just make another.
How the mini bear trap works
The scale of the trap has been designed to make it easy to make with hand tools and off the shelf parts. The torsion spring forces the jaws together, so when the tensioner is pushed down the jaws open. The trigger plate can then latch onto the teeth as seen in the video. The little notch in the catch has to be big enough to sit between the top of the teeth and the bottom of the jaw where the cut out is.
When the pressure plate is pushed, the jaws spring shut as the tensioner springs back.
Although the jaws look nasty, as long as you do not sharpen them or leave nasty sharp edges they will not cause injury. Do not fit springs that may be too powerful. Do not leave with small children or around pets in a loaded state. Obviously!
The slimmer you make the jaws the lighter they get; this makes them snap shut faster, but reduces strength.
The steel used is just plain 1.5mm sheet steel. I sanded it with p240 and liked the look of it, so I didn’t polish it any further. Finally I sprayed some automotive matt lacquer into the lid and hand painted it onto the metal to stop it rusting; before assembling for the final time. All holes are 2mm. The hole in the pressure plate hinge may need to be enlarged slightly afterwards. It may be a combination of removing excess metal from were it connects to and enlarging the hole. That detail can be seen in the video at 5.14.
I tested a few Torsion springs from eBay to get the best results. Here is what I used and works.
- 1mm diameter metal, 3 coil, 4cm legs (Single spring in final build and in video)
- 1mm diameter metal, 2 coil (This shape was cut to make 2 springs, only one used)
- 0.4mm metal, 4 coil (this was weak, but springs can be doubled up)
More than 1 spring can be added to increase power if you feel the trap is too weak. The trap will take an outside coil diameter of 6mm maximum.
Trap plans and template
All plans and templates are 100% free as always. Please like and share my videos to help support me and the channel. Thanks.
The above project is aimed at adults for education and entertainment purposes only, not to replicate. Anyone doing so takes full responsibility for their own actions.