Mechanism

Mechanism in a trick infobox explains how the pen is pushed to spin during the trick. Although it will be very difficult to notate the motion of fingers to push the pen, I, the admin, attempt to describe how to push the pen during the trick using some models and symbols.

This mechanism system depends on definition of the motion of fingers and hands. There are some tricks whose spin types and the appearance are the same but just ways of pushing the pen differ, as in Shadow and Neobackaround, Palmspin and Inverse Shadow, etc. Changes in the direction or appearance of spins can be tracked by the spin coordinate system, then we would require a structure that explains how the pen is pushed during a trick. In fact, as some of you may have already noticed, pen spinning tricks are results of push of the pen, and we can consequently identify a trick by a combination of determination of push style and corresponding spin coordinates.

1, I assume that there are three types of how to move a finger: to lower, raise, and wave, and later in Pen Spinning Trick Directory the following functions are employed to notate the motion of fingers during a trick (Table 1).

TABLE 1 Finger motion functions

Lowering a finger refers to moving the finger towards the palm, such as the motion of the middle finger which would touch the pen with the region 2p at the beginning of Thumbaround Normal T2-T1,
Raising a finger refers to moving the finger towards the back of the hand, such as the motion of the ring finger which touches the pen with the region 3u at the beginning of Charge normal 23,
And waving a finger refers to moving the finger towards other fingers, such as the motion of the index finger which would touch the pen with the region 2u at the beginning of Baktap Normal 12-12.
In specifying regions S, symbol ^ and parentheses ( ) are also used in the same meaning as in coordinates of spins.

In which the motion of fingers is qualitatively modeled, and then we can describe the motion of fingers as a combination of the above four finger motion functions.

2, Not only the fingers' motion influences the motion of the pen, and there will be another factor affecting the migration of the pen: the motion of the entire hand and arm (Table 2). The behavior of the hand and arm is crucial in some tricks such as Backaround and Fingerless tricks.

TABLE 2 Hand and arm motion functions

Lowering a hand or arm refers to moving one in a back-of-hand-to-palm direction as in Wiper Reverse T1. These motion must not be confused with raising the hand or arm with the palm up.

Raising a hand or arm refers to moving one in a palm-to-back-of-hand direction as in Wiper Normal T1. These motion must not be confused with lowering the hand or arm with the palm down.
Waving a hand or arm refers to moving one parallel to the plane containing the palm as in Baktap Normal 12-12.
The motion of the hand and that of the arm above three, or lowering, raising, and waving, are treated independently of each other.
Twisting a hand for the palm to show up refers to the motion of the hand as in Windshield Wiper Normal, and doing for the back of a hand to show up refers to the motion of a hand as in Windshield Wiper Reverse. To twist a hand will cause both of the wrist and arm to behave in the same manner.
Instead of region S, finger symbol A or H may be solely employed when an arm or hand does not touch the pen, but some fingers do.
- In specifying regions S, symbol ^ and parentheses ( ) are also used in the same meaning as in coordinates of spins.

In which the motion of the hand is qualitatively modeled, and thus we can notate the motion of the hand as a combination of these hand and arm motion functions. Nonetheless, only the motion of the hand and/or arm serving directly to cause some changes in those spins is notated as an element of the push in mechanisms.

3, Some other forces like the gravity, air resistance, friction may affect spins of the pen all the time when you spin a pen on the earth. Mechanisms will not mention those possible effects of gravity, friction, and resistance of air on spins of the pen in order to make descriptions briefer, although it is true that there are several tricks involving some indispensable roles played by those forces.

There are some tricks with no mechanisms denoted in their infoboxes. These tricks seem not to require any intentional control of the pen during or at the beginning of the tricks, in which some other forces, especially the gravity, are considered to drive the pen to spin.

4, Mechanisms notated in conformity with the above rules make more sense by being connected with coordinates of spins.

Write "psS*psD*...=rotations" when the push "psS*psD*..." ('ps' represents any kind of push) makes the pen rotate for that many of rotations, which is henceforth called an element. And, rotations in a element can sometimes be 0.25, if that should be the case, then rotations in the following elements will also be 0.25 or quarter integer larger than 0.25.
Then add a number to the head of an element according to the order of corresponding spin coordinates in which the push and rotations are achieved. For example, "1-psS*psD*...=rotations" means the push "psS*psD*..." makes the pen spin for that rotations at the beginning of the first coordinate. If "3-psS*psD*...=rotations", at the third coordinate. If "1,2-psS*psD*...=rotations", it means the pen continues to spin from the first region notated in the corresponding coordinate to the second.
Each element is shown by separating them with a symbol _ (underscore). Two consecutive elements often possess a common number on their heads, as in "1,2-" for the first, and "2, 3-" the second. In the second element, then pushing is supposed to be attained while the pen locates corresponding coordinate and after rotations in the first element, not just at the beginning of the coordinate.

Symbols * between motion functions are used for meaning the motions carried out at the same time.
Coordinates in parentheses are disregarded in relating an element to the coordinates of spins.
Fingers', hands', or arms' motion in catching the pen, or trying to stop the pen from spinning, is not notated. Even though such motion does make changes in spins of the pen in a sense, it also brings an end to the trick and is not as important or interesting to keep track of as in getting the pen to spin.

Again, it is not easy to express in symbols pen spinning tricks exactly and precisely, and it is possible that some people may not agree to some of the translation of analog tricks into digital notation of this website. The same thing can also be said to the current official notation convention of UPSB. We must remember that it is never easy to try to describe the rather fuzzy motion of the pen, as this mechanism system is an artificial model just created to try to better understand pen spinning tricks, as well as spin coordinates. In addition, mechanisms of some tricks may stretch the motion of the pen, fingers, hands, or arms a bit so that we can easily figure out what is going on during those tricks.

This mechanism system works based on the definition of symbols representing the motion of fingers, hands, and arms, which enables us to notate any pen spinning tricks, combos, and hybrids, without introducing new specific trick names on many occasions or interrupted trick notation attributed to existing named tricks for them. Some people who are already very familiar with general trick names such as Thumbaround, Shadow, Charge, etc. may think of combination of trick names and interrupted notation easier to comprehend than this mechanism system. However, the mechanism system functions on the principle of coordinates of spins and symbolization of finger, hand, and arm motion, which also results in a possibility of the new pen spinning world in which video demonstrations or the axiom of fundamental tricks are not always the only ways for pen spinners to exchange information.