Secret Spy Shoe





Introduction: Secret Spy Shoe

Secret Boot Heel Grappling Hook

1.  8" of 1/8" steel tubing
2.  10' of 1/16m or 3/32 steel cable
3.  1/16 or 3/32 wire clamps
4.  Old pair of shoes

1.  Drill
2.  Dremmel
3.  Welder (MIG, ARC, TIG)
4.  Wire cutters

Other helpful tools
1.  Torch
2.  Vise

Step 1: Cutting

Mark and cut the 1/8" steel tubing into two four-inch pieces.

Step 2: Bending

I found that the easiest way to bend the tubing was to put the metal in a vise and heat it up as hot as I could.  Then, I was able to bend it into a hook shape.  Do that with both pieces.  

Using my MIG welder, I welded the two hooks together.

Step 3: Cutting

Taking the hook and one of the old shoes, I traced out the hook pattern on to the heel of the shoe.  After doing that, I put the shoe in my vice and drilled a 1/4" hole 3/4 of the way through the sole of the shoe.  This is the point where you begin to dremmel.  I dremmeled out a pattern in the shape of the hook into the heel of the shoe.  I then drilled a hole through the heel and into the inside of the shoe.  It is through this that the cable will go.  Once I had the hook well-embedded into the heel of the shoe, I had to glue a small magnet into the heel to secure it.

Step 4:

To store the cable, I decided to use an old sock and a piece of velcro.  I sewed a band of velcro on to the sock so that it formed a little velcro latch that holds the cable.

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    71 Discussions


    2 years ago

    Cute video. That must have been fun to make. But he forgot his gun when going overboard!

    1 reply

    florman, you're probably safe, but please keep the following in mind:

    (1) Working Load Limits are for static (nonmoving) loads, not dynamic (moving) loads.

    If a cable breaks at 120 lbf (pound-force), a 95-lbf person jerking the cable at a rate of 40 ft/sec^2 would break the cable. [Calculation: 120 lbf * 32 ft/sec^2 / 95 lbf = 40 ft/sec^2]

    If a 95-lbf person were to swing on a 5-ft cable that breaks at 120 lbf, he would only have to swing 3 miles/hour (about walking speed) to break it. [Calculation: sqrt((120 lbf * 5 ft) / 32 ft/sec^2) ~ 4 ft/sec ~ 3 miles/hour]

    (2) Lucky for you, working loads are usually given a safety factor of 5, meaning that your cable shouldn't break until you give it a 600-lbf load. This means you (being 95 lbf) would have to jerk the cable at a rate of 202 ft/sec^2 to break it. You would also break it if you were to swing at about 6 miles/hour with 5 ft of cable.

    (3) Unfortunately for frisbeechampe1983's acquiantance, the combination of swinging and abrupt stopping when he hit the wall made a large enough acceleration for the load to exceed the cable's limit.

    (4) Additional notes: (a) Make sure you know the difference between mass and weight. (b) The working load limit is determined by a load being uniformly applied in a straight line pull. You are not only changing the load by moving along the cable, but any additional movement on your part makes it risky. (c) The tensile properties of the cable are changed every time you go on and off just because the loads are changing.

    1 reply

    Where are you hiding the pillow you need to sit on after your mom caught you rapelling in your Sunday clothes?

    "This is Maxwell Smart, secret agent 86, calling for Control! Come in, Control!"

    Hey mate, nice instructable, but I wouldn't recommend it on the way you use it...
    The cable is very thin and you cannot hold it very well for a slow rappel... Probably another use. But GREAT idea

    3 replies

    Just remember, that 120 is also in force. I knew a kid who tried to rappel a five story gym (our high school gym had roof access.) and he thought 550 would certainly hold him. it did for the first five feet, then he tried to do a jump, when he hit the wall, the 550 snapped. luckily there was grass below him, but he broke his neck. Just remember climbing rope is safely rated at 2200 pounds of force. (22kn)

    I don't mean that it gonna brake or something similar, the nature of that cable is not for rappelling

    Very nice. Can the hook hold all your weight for a ascent or rappel? I made a concealed grappling hook a long while ago. It was a belt. the clasp was a tri-fold and assembled quickly and locked into place. The rope was already tied and acted as a belt. It worked well but was a bit tedious to unwind and rewind around the waist. I like your velcro idea a lot :)

    1 reply

    thanks and the cable is rated to 120 so i figured since i'm only 95 i'd be okay

    Lads, that's a nice grappling hook with cable you've produced, but, it does occur to me that you have greater skills in producing interesting vids to demonstrate your new instructable. Whoever did the editing did a great job and the videoing was done well too.

    Here's my suggestion;

    Produce a pile more equipment accessories that are wearable and usable in emergencies and get yourselves a brand name too for those devices and vids.

    You've got talent, exploit it.


    1 reply