Big Design problem

We have been working on getting our design together to start ordering and fabrication in the past few days. Unfortunately, we have run into a problem in our concept that, embarrassingly enough, we overlooked while designing this concept.

The problem is overcoming the centrifugal force that will act on the roller as it spins around the composite disc. Because of the small radius and extremely fast rotation, even 5000 rpm, and 1lb weight estimation will cause approx 3000 lbf of centrifugal force. With our design that would require the spring to overcome that 3000 lbf to apply any force to the disc. I attached a quick sketch for clarity. 

We need to make drastic design changes, this will set us back enormously because we are suppose to be fabricating in a few weeks.

Winter Presentation Elevator Pitch

We made a video elevator pitch for our winter term presentation.

Quick Update Controls

In addition to solidifying detailed design, we are looking into the sensory equipment and controls we will need to implement. We will need a proximity sensor, strain gagues, signal amplifiers and a micro-controller at the very least. These are being spec'd out.

Spring Locking Mechanism Detail Design

We've worked on designing the locking spring force applicator and started a parts list and mapping out what materials we need to buy. detailed design is the first image and the second is the conceptual assembly.

Detailed design shows a large roller on an inclined linear slide. The roller slide assembly is pushed by the spring. This spring force will be adjusted by a screw in the back of the block.

This is a conceptual assembly. The detailed assembly design including motor, frame, bearings, and counter weight is next.

Piezo-electric concept will not work

We spent the last few weeks looking into what we need to build the piezo-electric concept. It turns out that our understanding of the actuators that we were hoping to use isn't near what we would need.

The actuators have a stopping force of 300lbs, but that is at 0.00" displacement.
The controller alone for what we are theorizing would cost up toward $30,000 and the actuators would be $2000 each. Way over our $3000 budget.

This means we will be falling back on our secondary design, the locking spring force applicator. This change late in the semester will set us back a bit.

Piezo-electric Design

We have decided to move forward with the piezo-electric design. We need to start detailed design of the piezo design to see if it will work with our budget. We have chosen the spring locking force applicator as our secondary design.

First Presentation

Our first presentation went well. We presented our concepts and discussed moving forward by choosing a concept and starting detailed design.

Rotating force

Linear actuator design

Piezo-electric Design seems to be ideal at this point.