Our final launch prototype (still 3D printed) on our test bench.

All of our learnings, notes, and an online survey, were our guide for our final design.

We learned that people liked a fully covered design more than a tubular design. Also, from our past prototypes, we found that using a belt drive in our system minimizes sound and eases manufacturing.

fenestra 1.0 was born.

A further refinement to our first integration. Also here, our alarm system is now integrated and functioning.

Our first compete integration.

What we tested:
All of our functional targets:
Integrate with SmartThings; ability to independently set-up to any size of window; movement control feedback, which allows the mechanism to sense if an obstruction was blocking the window and shut down.

Once again, what it lacked in beauty, it made up in functionality.

A new tubular design, testing how far we could minimize the packaging.

What we tested:
A simple and quick latch between the device and the window. This new concept worked like a charm.

Even though the metallic look was a suggestion from friends, we found this characteristic polarizing. People liked it, or hated it.

Painting the complete actuator in white, proved positive on surveys. People liked that it blended more with the window frame.

1st demo version of our tubular design explores a polished metallic look.

What we tested:
Can a tubular cover for the actuator be both a cosmetic cover, as well as part of the mechanism?

Using a tube as the cover and as an integral part of the mechanism was our breakthrough with this prototype. This new design concept allowed us to package the mechanism on a much smaller footprint and overall volume.

Our first mechanism to achieve all of our functional goals. What it lacked in beauty, it made up in functionality and learning oportunities.

Most important lesson learned: it has to look good and seamless with the window! This was a good enough prototype to clearly realize how it was NOT good enough.

Back to computer design!

Let’s give this thing some brains and make it communicate with the SmartThings platform.

Intermediate mock-up to explore a mounting options and a release latch between the windows and the actuator.

Our very first successful actuator using our own design for the mechanicals and the power electronics.

Very important lesson learned: the actuator needs to have a quick release latch. Not only is it unsafe to have a window bolted down, but also installing the actuator that is permanently attached to the window is very cumbersome!

Knowing the magnitude of the loads involved in moving the window, we set ourselves to test the smallest motors we could find and ran them using only 6V

These tests where successful, but we learned how alignment of the system is very important to keep energy consumption low.

What loads are involved in sealing and un-sealing a window?

Not so much, if you do it correctly! If the opening force is applied at the base of the window, both the friction force, and the actuator force are almost co-linear. If you try to open the window, from the top end of the window (as some suggested in order to hide the device), the friction force and actuator force are not collinear and create a moment force which “cocks” the window and greatly increases resistance.

Where can we drill on a window, without ruining a double pane window?

Not much! Any drilling on the window frame could very easily get into the sealed space between the window panes, and if you damage this, the vacuum between the panes is lost, and the window ruined.

Knowing the loads involved, and the drilling limitations, we designed our system around the 3M VHB adhesive (video below)

Market research begins, feasibility of product starts.