Mechanical
Calvin was designed with mechanical simplicity in mind. In order to minimize man-made error in fabrication and assembly of components we created a minimalistic design using a single crane/arm combination with diverse functionality. These component’s motions are actuated by servo motors controlled through the TINAH board which is coded for Calvin to use his arm to pick up agents, as well as place the agents on the zip-line.
What Does CALVIN Do?
Infrared Signal Frequency Detection
Line Following
Retrieve Agents
Zip-Line!
Major Mechanical Components:
Main Chassis
The main chassis is fabricated out of 3mm thick hardboard fabricated from a laser cutter and assembled with meccano pieces and hot glue. The chassis has many holes cut into it to allow wires and zipties to weave through it.
Crane
The base of the crane is made from multiple 6mm acrylic components including a gear and a servo motor mount as shown below.
The crane itself is constructed of 4 threaded steel rods that hold the arm base on top.
Arm
CALVIN’s arm is connected to the rotating crane which extends from the rear of the chassis, and has the claw mounted by the four front holes. The arm is fabricated from 6mm thick hardboard and is gear actuated by the smaller gear attached to a servo motor (not shown).
Claw and Claw Mount
All claw and mount components are fabricated from 3mm thick hardboard, and the four mount pieces are held together by four metal rods connecting them to arm, as well as several elastic bands wrapped around them. Elastic bands were preferred over a more permanent solution such as hot glue or epoxy to allow for ease of servo motor or claw replacement, without sacrificing any mechanical stability. One claw is attached to a small servo motor (not shown), and actuates the other claw with an even 1:1 gear ratio.
H-Bridge/IR Filter Boxes
These boxes are constructed out of 3mm hardboard and made specifically to hold our two H-Bridge circuits that drive our two wheel motors. The H-Bridges are mounted under the chassis to conserve space and thus require some form of protection from external contact. A similar box was created for the Infrared signal filter circuit.
TINAH Board Mount and Wire Box
This main box is constructed out of 3mm hardboard and is designed to mount our TINAH board face up to allow interactivity with the screen, buttons, knobs, and inputs/outputs while also having space underneath it to sort and hold a majority of CALVIN’s wiring.
