magnetic padlock

This is a padlock that can be made by children

You need a small amount of card, a ring magnet and a paperclip. The most difficult bit is bending the paperclip. Make the box to suit the ring magnet, it should be a loose fit and about twice as thick as the magnet. Took 15 years to design.

The lock needs something to prevent the hasp being simply pulled through, in this case I used a plastic bead

In order to open the lock something metallic must be held against one side to attract the internal magnet away from the side of the hasp with the hook. This shows the hasp partly withdrawn although for some reason the scissors are on the wrong side of the lock

and this shows the hasp fully withdrawn

This is an example made from transparent acetate

This shows it unlocked

This is its predecessor

It is made from a sandwich of dark transparent perspex glued together, the barrel is made of a 1cm length of round steel bar, it has a radial hole with a small metal peg projecting. This rotates with the barrel and jams or un-jams the hasp, you grip the barrel between thumb & forefinger to rotate it.

The hasp has a notch filed in it near one end. To open it you have to know to hold it up to the light, then you can see the mechanism.

shimming a padlock
how to pick a padlock
how to open a combination lock
demonstration of lockpick
make a lockpick
yale lock animation
lego robot cracking combination lock

coke-can combination lock

Simple combination lock made from a soft drink can with the top removed. Two cardboard rings are made by laminating bits of toilet roll together with PVA, then stuck to the can with small bits of double-sided sellotape

A double lid is made from thin card in such a way that one can rotate inside the other. Both lids have an internal cardboard bump that rotates against the cardboard rings. The lid can only be removed by lining up the bumps.

The internal lid can be rotated independantly of the outer one by means of the oval cutouts in the sides of the outer lid.

This shows the outer lid marked out, the inner lid fitted on the can.

This shows the lid in place, the box can only be opened by rotating the inner lid to the correct alignment with the outer lid

This shows the lid removed

maze lock

Simple maze lock made with similar techniques to the combination lock; I used rubber bands to hold the strips of card in place while the glue dried

in order to be opened the lug inside the cardboard sleeve must thread the maze

this shows the lock closed & the sleeve in place, the bottom of the sleeve is reinforced with an extra ring of card to prevent it distorting

this shows the lock partly open

movie on youtube, version made with a see-through sleeve
origami puzzle box
similar thing made with 3D printer $16
front door chain works like this
illusionist locket made with 3D printer

Bead lock

This is a lock for a miniature fruit juice bottle

the cardboard collar fits round the neck of the bottle and slips preventing the cap from being removed; the collar can be jammed against cap using a plastic bead

the bead rests on the cardboard flange and can be positioned between the two drops of hot glue

this shows a hole cut in the cardboard flange so that the bead can be hidden in the space between the cardboard collar and the bottle. An acetate disc has been stuck to the cap to prevent the bead falling out

This shows the bead inside the space between bottle & collar, it is free to run right round the circumference so it is usually hidden

You can just see the plastic bead in this picture looking up through the base of the bottle

Bolt cutter

This is a simple bolt cutter

made with a lathe, bridgeport milling machine, tap & die, grinding wheel

jaws are pushed together by screw, this could probably be re-designed round a large nut & bolt as the thread is quite difficult to make

this shows inside the thread with the top of one of the jaws

this shows the jaws, the one on the left has a flat side so it can slide past its retaining screw

this shows the sliding jaw & its retaining screw, the retaining screw goes in the back

the smaller jaw is stationery & doesn't need to slide

This is a closeup of the jaws, they are made from heat-treated silver-steel bar, although it may have been possible to make them from a drill bit/bits

wikipedia on lock picking
safecracking robot
another safecracking robot
doing it with numbers
richard feynman on safecracking. Starts about half-way down the page
history of locks
all about safes
useful gadget
animation of lever tumbler lock
my email is
back to main site