Extending Punching Gun

Scissoring mechanisms are ubiquitous in our society.  Whether lifting workers so they can reach a high item, jacking a car up for roadside repairs, or making a table foldable, scissoring mechanisms are integral to our society's functioning. And, I believe, made invisible by its ubiquity, the most benevolent, the most comical, and lighthearted use of scissoring mechanisms is that which extends a boxing glove. The innocuous, seemingly unattached boxing glove that suddenly shoots forward is cause for great amusement. 

Most of the scissoring punching devices I have seen are bulky things that require both hands to operate. Even some that require only one hand to extend the boxing glove require the user to use the other hand to reset the mechanism. I want to design and build an extending punching gun that requires only one hand to operate. Here is how I did it:

A scissoring mechanism is a pair(s) of linkages that extends when the ends of a linkage pair are moved together. In essence, the linear motion of moving a pair of linkages together creates a perpendicular, linear extending motion. The mechanism can extend further or shorter distances depending on the number of linkage pairs. However, the addition of extra linkage pairs increases the force required to extend due to mechanical disadvantage. However, mechanical disadvantage will not matter too much because the boxing glove will be low in mass. 

The biggest problem, as I saw it, was actuating the scissoring mechanism. Somehow, a trigger pull would need to be converted to linear motion. That linear motion would then push two scissor linkages together, extending the punching glove. My initial solution to the problem consisted of a rack and pinion system. The trigger would be an internal gear (much like the trigger from my Micro-G Dice Blaster). The trigger then meshes with a small gear concentrically connected to a bigger gear. The bigger gear then meshes with a rack that itself is connected to the scissor mechanism. Thus, a trigger pull is converted to linear motion that actuates the scissoring mechanism.

Much to my surprise, this mechanism performed admirably immediately.  The only fault is the trigger did not spring back after being pulled as intended (this would have been accomplished by connection one end of the rack to a static part of the handle with a rubber band; this failed because there was too much friction between the rack and the parts that indexed it even with copious lubricant). I apologize for not having images of my CAD files; I designed and printed this within days of leaving for university combined with my Solid Edge license expiring the day I finished CADing. I do have images and videos of the finished product; those are below.