I could think of about a hundred ways to make a simpler clock, but this Ball Bearing Clock looks fantastic. Video after the jump.

"I though about building a clock with a pendulum activated by the fall of bearing balls. The first thing to design was the engine which was to sustain the pendulum’s oscillation: how to get enough energy from a ball to make this possible? The balls had to be heavy enough to run a stable course but their size obviously determines the clock’s size. As a trade-off between weight and size I arbitrarily picked a 19.8 millimetre diameter for the balls. I could picture the running clock in my mind, and I believed I could complete it in three months… The engine’s first prototypes were just unbelievable, at that time I thought that I needed as much gain as possible to achieve the largest possible amplitude: after a month of effort I had achieved a 60 centimetre swing with a 1 meter pendulum. That’s when I stumbled across an old physics book from 1894 which explained that the isochronism of oscillations is only true for small amplitudes, not large ones. A month of work for nothing. I was now left with the reverse problem to solve: achieving the smallest possible amplitude with 20-millimetre balls. It took me another month to design the final version of the engine. "

(more…)

Here is a simple design for a DIY metal detector that uses a beat frequency oscillator.

“BFO ( beat frequency oscillator ) metal detectors use two oscillators, each of which produces a radio frequency. One of these oscillators uses a coil of wire that we call the search loop. The second oscillator uses a much smaller coil of wire, and is usually inside the control box and is called the reference oscillator. By adjusting the oscillators so their frequencies are very nearly the same, the difference between them is made audible as a beat note, this beat note changes slightly when the search loop is moved over or near to a piece of metal. It has been found in practice best to make the search oscillator fixed say at 100khz and to arrange for the reference oscillator to be adjustable 100khz plus or minus 250hz. This gives a beat note of 250hz to 0 to 250hz. The beat note disappears or nulls when the two oscillators are about equal. This type of detector is most sensitive when the beat note is close to zero, about 5hz ( motor boating ) any slight change being noticeable.

Parts list

Power source:
Any 9v battery PP3 is ideal.

Capacitors:
2 off 220uF 16v electrolytic.
5 off .01uF polyester.
5 off .1uF polyester.

Resistors:
All resistors 1/4 watt 5%
6 off 10k
1 off 1K
1 off 2.2m ===== 2.2 Mega ohm
2 off 39k”

(more…)

So you have a PC toaster but now you need a deep fryer. Have a look at the Deep Fryer PC for some inspiration.

“Got a PC, but forgot to buy a Deep Fryer for that weekend party? Fear not! There is a solution! Just grab that high-end PC, stick it in a bucket, fill said bucket with oil, and play a CPU intensive game for a little while. In no time, your fryer oil will be hot enough to cook you some tasty treats! Great for the time between frags…”

Via: Digg

(more…)

Here is another cool video of a Nintendo Wiimote controlling a robot.

Video after the jump.

“Control a LEGO NXT mindstorms robot with your Nintendo WiiMote and a S60 3rd edition phone.”

(more…)

If you have a big enough back yard, you too could build your own wood roller coaster just like Jeremy Reid has done.

Here are some other to have a look at:
Link 1
Link 2
Link 3

Video after the jump.

“Style: Out and Back
Height: 17 feet
First Drop: 20 feet
Top Speed: 20 mph
Track Length: 444 feet
Max Positive G’s: 3.5
Max Negative G’s: -0.2
Material: Pressure Treated Southern Yellow Pine
Number of Drops: 4
Lift hill angle: 26.6 degrees
1st Drop: 54 degrees
2nd Drop: 43 degrees
Curve banking: 50 degrees
Duration: About 1 minute
Cart: Single Car, Wood and Steel Construction
Capacity: Single Rider
Chain Lift: 1HP Motor, 3/4″ Pitch Roller Chain/Sprockets

Overall:
9,500 lbs (4.75 Tons) Lumber
7,000 Screws/Nails
2,900 board feet of lumber
Investment: $5.5k ”

Via: Micsaund

(more…)

This Van De Graaff project allows you to play with high voltage on the cheap.

“The base is an old laundry bucket , inverted. Lay the power roller and motor on top of the bucket and mark the location of the mounting holes and roller location. Using those markings locate the closet flange and mark it’s mounting holes and the area inside to be cut out. Cut out the hole to match the closet flange and drill out all the locations for assembly bolts.

The column is easy, simply mark down one end a distance equal to the height of one mixing bowl, now mark four points equidistant around the pipe at that location. Drill a 2″ hole through the pipe through two opposite points and a pair of 1/8″ holes through the other two points.”

Via: Make