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Seek and Geek 2: Three Hole Punch

I recently switched from notebooks to binders for my academic note taking. The switch required me to pick up a three hold punch.

My first purchase was a bad one. The punch (shown below) was light and easily stored inside a binder, however the short moment arm made it very difficult to punch holes. The protruding pins also hindered my ability to properly align the paper. Further, the rotary mechanism made it so that only a single sheet could be punched at a time. As a result the first few lecture's worth of all my notes are very haphazardly placed in my binder.

To remedy the issue, I decided to get a new hole punch (pictured below).

This much beefier model from Swingline took care of all the gripes I had with the old model with the only trade off being decreased mobility.

The new model uses two levers in series to create mechanical advantage so I am able to punch more paper with less effort. The calculations below show that the mechanical advantage of the two lever system on the new punch is 9x as compared to the old punch which only gives a 2x advantage (neglecting friction and the restoring spring force in the new punch).

Another advantage is the spring loaded mounting and linear motion of the cutting pins also allows me to easily align 20+ pages at a time.

Finally, the shape of the cutting surface of the Swingline hole punch (depicted below) further lowers the input force requirement.

This is because the cross sectional area of the paper being sheared at any time is lower compared to a normal cylindrical punch. As a result the cutting process is spread out over the stroke period of the punch and the force requirement is lowered despite work remaining constant.

Hindsight is truly 20-20. I now realize I will very rarely (if ever) need to punch holes on the fly as opposed to at my desk, and the potentially enormous performance jump between a $4 and $15 piece of equipment. Hopefully this analysis will make me a bit less blind moving forward.