You might want those to go with something visual like a lift operating, or the controls on some weird gadget. This one is optimised to sound like a range of nasty industrial devices you wouldn't want to poke your fingers into. For more specifics on machine component design see that section in the sound design tutorials. Here's one with shrinking powder applied.
By making spectrums that are rich in modulation frequencies and speeding them up and down. We get our signals by AM mostly. We start by pairing sines together that can give sharp metalic textures. An arrangement of four modulated together gets us a good starting signal with lots of undulations, wobbles and phase changes occuring. Then we use this signal as the modulator in an FM step. This lets us control the brightness/harshness of the sound as well as the beating patterns and works well in combination with the final stage resonant low pass filter to shape the tone and get an even sound rich in spectral rythmns which follow the low frequency components of the beat frequencies (in quite spectacular ways for a few hard to find "good" settings).
In the "gears" section four sines are combined to provide the frequency control of a single sine oscillator. A bandpassed slice of this spectrum is amplitude modulated with a completely new 5th frequency. In the "motor" section a more direct form of FM is used and combined with noise bursts to emulate an alectric motor.
There are controls for four separate base frequencies fa1 and fa2, fb1 and fb2, which you should use in pairs. You dont have to because the modulator is symetrical and any pairing will work, but it helps to remember that you often want one pair quite low and close together to get a good bass noise, and another pair much higher and further apart to get a whiney grindy noise. The next two controls set the base frequency of the FM stage and its modulation index. The last three set the frequency and Q of an output filter, and the final amplitude. The motor sound has it's own separate synth. This is good to create the illusion of two things that work together in a less than perfectly synchronous way. The motor has controls for the louness and dimention of the brushes, the rotor harmonics and a couple of other parameters that approximate to the material hardness and size of the coupling body. Both motor and gears have their own volume control. There is a start button and a stop button. Speed up time of the motor is governed by the its "load" setting.