Week 7

Meleigha and Amber


So after constructing our first pseudo prototype, we have discovered some major problem areas.

First of all, we need a very high torque motor to pull the strings that would ultimately retract the arms of the umbrella. To address this, we decided to change the material of the arms from steel to hdpe (high density polyethylene) plastic. HDPE is highly flexible so it will allow for a smaller gear motor.

Next, we wanted to change the way the arms bend. The problem currently is that the arms are made of a single flexible rod. The entire arm bends when the string is pulled which creates the "inelegant bulge." To fix this, we imagine having wooden/inflexible dowels for half of each arm with the new plastic attached to the dowel. This will make it so only the tips of each arm are flexible, and therefore creates a more gentle curve.

Our plan of action is to buy a new set of materials and play around with the assembly to improve upon our preliminary thoughts.

Along with an effort to reduce the amount of torque necessary to pull all of the strings, we are also researching the appropriate motor to drive our umbrella. In addition, we are trying to resolve how the motor drives the center ring that pulls the strings and releases them, and how this stays stationary on the shaft until moved by the motor.