Off on a tangent: Making tangential force application work

The task of moving condoms from tangential force application is not an easy one. To tackle it, I've broken down the process into a few steps. Firstly, applying force to move the condom from below only. Second, ensuring that only the bottom condom is vended. Thirdly, real-world testing, since condoms aren't exactly a nice clean form factor, which will doubtlessly cause many issues.

My initial attempts were to model different materials for the pushrod, or scraperod. It quickly became apparent that this was an issue of surface area more than material, and perhaps a combination of the two would fix things. I played with the profile of the scraperod in a very non-scientific way, and observed that a non-regular radiused, long surface made huge improvements. The irregular radius -- a simple parabola offset from the centerline (Fig. 4) allows more pressure to be applied at the end of the axle rotation, ensuring the condom is in fact completely moved out of the inventory tube.

Figure 4: Scraperod Design

By using this design, I believe I successfully met my first step. The next will be to address the issue of moving only the bottom condom. This may involve applying extra downward force from a spring and plunger assembly in the inventory tube, or perhaps by redesigning the inventory dispensing slot with a flap of rubber to prevent distribution.

Below, video of simulation of the scraperod system. I've modeled the coefficients of friction very roughly from internet data, and obviously the condoms are still approximated as square boxes. I'm quite pleased, it seems to function better than the previous pushrod design.