Combo Lockpick/Howard Community College/Fall2012/p1-502-hwht/Friction Decision Matrix

We have made a decision matrix to assist in deciding which material we will use to increase the friction so the lock won't slip when it is being turned to find the combination. The solutions we came up with are as follow. A video can be found at

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We will cut a small piece of sand paper and line the inside of the ring that will hold the knob on the lock with it. This will be used to increase the friction by applying the lock to a coarse surface.


We will us a clay like substance to make an imprint of the lock on the inside of the ring and harden it so that we have a permanent fit of the knob in the ring.


We will use a soft foam like substance similar to memory foam on the inside of the ring to have the lock be held and have to ring be able to fit a variety shapes.


We will line the inside of the ring with putty so that there will be a surface that is sticky to hold onto the knob, but it will not permanently stick to the knob.

Rubber Stopper:

We will drill two holes in a rubber stopper that we have in order to make a new part that will fit on the end of the knob and attach to the stepper motor in a cost effective way..

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Force the Knob:

Will force the ring onto the knob to help it get a better grip in a cost and simple way.

The Google doc is at Friction Decision Matrix. DO NOT TYPE IN THE DOCUMENT. DOWNLOAD IT AS AN EXCEL DOCUMENT AND THEN FILL IT OUT. After you have filled this out, save it and email to

Thank you for your cooperation.