Some sound effects can be designed by recording and combining sounds from certain items commonly found in your own home. A mechanical door with locking mechanisms like the effect found below could be made with: microwaves, ovens, VCR's, deadbolt locks, washing machine dials, toasters, can openers (both electric and manual), stereo equipment, etc.
I designed and recorded the following sound effect by: opening and closing a microwave door, closing an oven door, microwave button beeps, spinning a plastic/metal clothes hanger, bending the leg from a toy robot dog, and blowing air near the mic.
