In this semester-long project for Mechanisms, our group was tasked with designing and building a Rube Goldberg mouse trap containing at least 4 different types of simple machines, with no type used more than twice.
From the start I proposed that we used an IKEA SKÅDIS pegboard as the structural mounting platform for our system. The slotted style holes seemed like they would provide more secure attachment points in comparison to the standard circular holes used in regular pegboards. After finding a suitable mounting design online, I set about recreating it in SOLIDWORKS so I could share it with the group.
The primary feature of our project is the decreasing-radius spiral marble track, as seen above in the 3D model. With more SOLIDWORKS experience than the rest of my group members, I wanted to try and push the envelope (both figuratively and physically) on what I could design and actually manufacture. Having recently completed the surfacing section of my intermediate SOLIDWORKS course, my goal was to produce a track with smooth organic transitions as opposed to simple extruded geometry.
The upper section of the track begins with a large diameter and shallow pitch, and transitions midway into a tighter radius with increased pitch to allow the marble to gain momentum before rolling off of the end ramp. I found out early on that the standard helix feature only allows for a single constant pitch and diameter going completely vertical, and decided to use two equation driven curves which provide full control over the pitch, slope, and start/end positions.
Due to its overall scale, taking up almost 75% of the pegboard’s height, the track had to be divided into 22 printed sections, 11 of which serve as the mounting extension arms. Each section is joined using custom swept dowel pins, created by offsetting the original equation driven curves. This allowed them to pass cleanly through the track’s internal geometry without poking through the outside edges or interfering with the marble path. This approach allowed for precise alignment of each section while maintaining the appearance of a single continuous form.