Archive for the ‘Exercise 6: Mechanical Motion’ Category
This was supposed to mimic this. Alas, the movement of the twin stick was so jerky that I couldn’t imagine it actually working (especially because I was busy with mid-terms…).
This mechanism was hand-cut from foamcore after being drawn on engineering graph paper. The gear train consists of pinions and a rack. By turning the small gear using the crank the large gear rotates in the opposite direction, driving the rack forwards or backwards. While the gears do mesh and work, they degrade quickly with use and now are fairly difficult to turn. It is still interesting that a mechanism can be easily prototyped using inexpensive materials.
For this assignment, I built an object that plays music by hitting metal keys with mallets. The mallets are manipulated by a dowel with boards glued to it that hit the mallets when the dowel is turned.
This is a hand I made out of MDF and some dowels. The fingers and joints are constructed so that they move as real fingers do and can’t be bent backwards. It is has no actuation built in at the moment, but I have big plans…
Geneva drive- a mechanism that translates a continuous rotation into an intermittent rotary motion. It is an intermittent gear where the drive wheel has a pin that reaches into a slot of the driven wheel and thereby advances it by one step. The drive wheel also has a raised circular blocking disc that locks the driven wheel in position between steps.
This is a crank I made, when you turn it the speech bubble “I need COFFEE” appears.
The mechanical hermit doesn’t like being bothered. When the kids get close the hermit uses one leg (a crank slider on a dc motor) to get away. When kids get really close, it uses the crank slider and another mechanism (a four bar linkage on attached to a servo) to move faster. Distance is determined by a range finder.
Arduino Sketch: kv_MechHermit
Analog sensing/ curiosity cabinet
Mechanical (gears and levers)