Gearbox Puzzle

Spaz comes to a shut door, it seems that the opening mechanism is a gearbox located on the wall next to it, but the gears for the mechanism are all lying on the ground. Spazz must do two things to solve this puzzle: (The player does this by dragging and dropping the gears from the gear bank onto slots in the gearbox. There are many gear slots and a limited about of gears that come in three different sizes. There may be multiple ways to bridge the gap but there is only one proper choic for the first and last gear combination.) Once Spaz has completed the puzzle he will be able to use the crank shaft on the first gear to raise the door.
 * 1) He must select the proper first and last gears to provide enough torque to lift the door.
 * 2) He must bridge the gap between the first and last gears.

Hints: Notes are written in chalk on the frame of the gearbox, it seems as though someone was trying to fix this sometime in the past. (This puzzles can teach the player the simple relation between Power, Torque and Rotational Speed which relate to gear ratios. )
 * Power = Torque * Speed
 * Torque ≈ 1 / Speed
 * small to large = most torque