I have looked almost everywhere to find a Hidden Blade Design, but I couldn't. So I decided to make my own. It is not spring loaded, it is not hard to build. If you make the holder out of wood and the blade out of plastic it would cost you about 20$, if you make the blade out of metal and the holder out of wood it would cost you about 25-30$. If you have any suggestions about this please leave a comment

IMPORTANT: The drawling are not to scale, they are just to show you how to put it together

Step 1: Supplies

You will need:
Two 7 x 2 x 0.75 (Wood, metal, ect.)
Two 7 x 0.5 x 0.75 (Wood, metal, ect.)
Plastic blades, or metal blades
Super Glue, or a solder
A will to build.
Money

Step 2: Making the Blade

First we make the blade probably the easiest or the hardest part of the project

You should first make 3 blades accordingly to the design.
--And insert the shortest one into the second biggest one.
----Insert the Blade Part 4 & 3 into Blade Part 2 .
------Then Super glue or solder the end of Blade Part 2, NOT Part 3 or 4, to Blade Part 1.

(Optional) The Blades do not have to be medal they could be plastic or any other material you prefer.

If you are under 10 or do not know what solder or where the super glue is have Parental Guidance.

Step 3: Making the Holder

Once you created the blade, we now create the holder.

You first need 3 peices of wood the size described on the design.

--Cut along the dotted like for Part 1, Part 2, and Part, 3
----In Part 1 Throw away the 5.5 x 2 x 0.45 inch piece and keep the 7 x 2 x 0.75
------In Part 2 keep one of the 0.30 x 2 x 0.15 inch or keep both if you want a back up.
--------In Part 3 keep the 4.5 x 2 x 0.30 inch and throw away the 7 x 2 x 0.70

After you do that super glue or solder the end of Part 1 to Part 2. Then solder Part 2 to Part 3's end. Lay it on its side until we need it again.

I would prefer to use wood for this because of its ability to be cut easily and into more exotic shapes. But if you are good with metal or any other material go with that. But do not use card board, it is flimsy and I do not think it comes in a 7 x 2 x 0.75.

Step 4: Putting It All Together

Now we are going to put the whole thing together.

You will need whatever has a * next to it.

You will need:
*--The finished blade (Learn how to in Step 1)
*--The Holder (Learn how to in Step 2)
--A coke (Learn how to at a place that sells cokes ex. Target)
*--Two 7 x 2 x 1.5 inch material (What ever material you used in step 2)

Take the Blade and retract it
--Test it to make sure it slides out freely
----Next slide it into a part of the holder that it can fit in
------Test it with your hands as a wall.
--------If it works take one 7 x 2 x 1.5 inch material and place it on one side.
----------Solder or super glue it to the holder
------------Then take the second 7 x 2 x 1.5 inch material and place it on the other side
--------------Solder or super glue it to the holder

Test it out make sure it works if it does then move on to the next step. If it doesn't check to make sure you did all of the steps correctly. If you followed them correctly and it still doesn't work then send me a message on what it won't do.

Step 5: The Wrist Holders

This you can use rubber bands, rope, string, yarn, metal, plastic, or a cloth to rap around your arm. It doesn't matter.

Step 6: How It Works

Hook it up to your arm in some way described in Step 5.
--Thrust your arm forward so the blade will slide out. Make sure the blades do not fall out and that the holder stays in tack
----If the holder starts to fall apart I would super glue the outside of the holder.
------If something doesn't work send me a message and I will correct the design