I started to build the odd circuit and nearly every component I picked up and soldered was giving me a problem. The one problem we all suffer from at one time or another is dry joints, looking at my components it was very clear to me that they needed cleaning so I set to work with wire wool; this was boring so I looked in my catalogues to see if there was anything to do this, there were things to clean PCBs and other nick nacks but nothing to clean components.
I dived into my junk box and came up with a small 12 volt motor, a switch, and wire - so I went into the house and saw a cotton reel in the wife's sewing basket. I took a scouring pad from the kitchen and an idea was forming in my mind to use these somehow with the motor to do the cleaning job. I cut the width of the scouring pad to fit between the rims of the cotton reels and glued it in place, round the circumference with a rubber based glue. The first attempts at driving the reel on the motor shaft resulted in the pad coming adrift but after applying plenty of glue to both the reel and the pad, letting it dry and then squeezing then together, it held.
This became Mk. I cleaner. Mk. II was created when I made the motor switch on automatically using an LDR to sense that my hand was near and Mk. III and IV used a second motor rotating in the opposite direction so that the component was cleaned as it was held between the rotating reels. The motors are small, low torque units which can easily by stopped by hand so there is no danger of injury if you come into contact with them. Remember you can reduce the torque of the motors by reducing the supply voltage. I would like to get some feedback on this device so if you build one please let me have your comments, (good or bad). Please drop me a line. Happy cleaning!
It is possible just to solder the components together rather than make this circuit up on a stripboard or PCB. By replacing the motors with a buzzer this circuit can be used as an intruder alarm.
The Plan View shows how the LDR is positioned close to the drums so that the speed can be controlled by the hand when cleaning a component.
The drums are made from cotton reels with scouring pads glued to them. The centres of the cotton reels have PCB stand offs glued into them and drilled to suit the diameter of the motor shaft.