Air ScribesPneumatic air scribes were developed as powerful industrial engraving tools. Basically, the air scribe is a small, hand-held air hammer that is operated by compressed air at about 90 pounds of pressure per square inch (psi). Under this high pressure, a piston within the unit drives a hardened bit at blurring speed against whatever object it is pressed. In engraving, the bit can scribe into the toughest of steel alloys; and in fossil preparation, the reciprocating action of this bit can rapidly disassemble the hardest rock. With a little practice and a light touch, matrix rapidly turns to grit and falls away from the fossil. Under magnification (a binocular 4x lens headband-type magnifier is good) the matrix looks as if it is melting. In reality, in addition to a powerful but tiny hammer-chisel action, a harmonic vibration is established, and grains of cemented rock are vibrated apart by waves of energy. These energy waves, of course, also travel through the fossils, and it is the difference in density between the rock and the fossil that allows the fossil to remain intact, at least most of the time.

THE MOTORMost hermetic compressors use induction motors cooled by either liquid or suction-gas refrigerant. Induction motors have copper windings that, when alternating current is run through them, create the magnetic fields that cause the motor to turn. These copper windings are bulky, adding size and weight to the compressor.Two-pole, 60-Hz induction motors operate at approximately 3,600 rpm. A higher number of revolutions per minute can be obtained by increasing the frequency. Compressors that require higher shaft speeds tend to use gears. While gears are a proven technology, they create noise and vibration, consume power, and require lubrication.The magnet-bearing compressor features a synchronous permanent-magnet brushless DC motor with a completely integrated variable-frequency drive (VFD). The stator windings found on conventional induction motors are replaced with a permanent-magnet rotor. Alternating current from the inverter energizes the armature windings. The stator (excitation) and rotor (armature) change places. No commutator brushes are required. The motor and key electronic components are internally refrigerant-cooled, so no special cooling is required for the VFD or the motor.

14. How to back down a winding road if you are headed uphill and your engine runs out of gas or stalls. I tied a safety line onto the front of his kart and continuously pulled him back up the hill to start over and over again until he learned to back down with full control. This training also taught him what to do if your brakes can''t hold on a hill. This may save his life someday. (Many a person has died trying to back down a road on a hillside and making a simple braking or steering mistake.)15. How to lose privileges when you don''t follow directions!

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