Spring 2016: 3DoT Spider-Bot Mechanism Research
BY: Omar Mouline ( Project Manager)
Introduction
The 3Dot David project mechanical requirement was to build a small size spider bot that can walk using two motors. When the project was assigned to us, We were given The hex bug 1 in the picture below as a prototype. 
Related requirements
- The 3DoT David shall be a low cost project with a total cost that does not exceed $79.95, which includes the cost for manufacturing, PCB, battery, and other components.
Table of Contents
Research different mechanisms of spider bots
After conducting some research on other types of mechanisms, the first design that attracted my attention was a toy named “Combat Creature”. The Combat Creature is a discontinued toy that i believed was cooler that the hex bug to build.
Combat creature
A 3 part video Youtube video of disassembling the toy was found explaining the mechanism and showing the different parts of the robot: Part 1, Part 2, and Part 3.
Jerry Mantzel mechanism
Jerry Mantzel project was to build a Giant Version of the Combat Creature. Inspired by the combat creature, he adjusted the design of the toy to make a Rapid Prototype as shown in Video. Adjustments were made To have an easy prototype to 3D print as shown in this Video.
Hex Bug 1 Mechanism
This prototype is the design that was assigned for our project. The picture on top show the exploded view of the cam based mechanism of the spider bot.
Hex Bug 2 Mechanism
This design is the new design we are using for our project. It is less complex, gave us less printing time, All the parts can be 3d printed, and reduce the cost of manufacturing.
Joe Clan Mechanism
On this design the Spider Bot move side ways. I found a lot of information in this Page. The Professor provided me with more links for this model:
Two motors controlled transparent Joe Clan
Phone Controlled based Mechanical Joe Clan Spider
Theo Jansen Mechanism
Links That explain more the mechanism of this Spider Bot:
Details on Theo Jansen mechanism
Walking machine in the middle of construction
Conclusion
After looking on all of these design, we started working on the Hex Bug mechanism 1 and on process of designing it on solid works we quickly started running to problems. Trying to solve all the problems the main issue we had is the 3D printing quality for the small joints and some other parts. for that small design we needed precision in order to get the result we want specially for an important part like the joint. We then decided in the tenth week as a team too change the design to the Hex bug mechanism 2 which is less complex. Gladly, we were able to make and achieve all the requirements.