Week 10/11 - Light at the End of the Tunnel

Wow. 2 weeks until the deadline, and we've changed our design... again!

First we had the substitution of the winch idea for a kind of archimedes water screw that would lift numerous ball bearings up to the top of the receiver, to let them drop down the chimes again. In the end, it was decided that with our somewhat limited skill set, it would be wise to simplify the design. The original idea was that the chimes would be hung vertically in a circle, and a central reel with a beater attached would rotate with the help of some kind of drive shaft. We then extended this concept to arrive at our FINAL decision.

Each chime (still hung vertically, though now in a row rather than a circle) is aligned with a servo motor do-hickey, capable of 180 degrees of rotation. Attached to said motor is some sort of hammer. Piano string strikers were considered, but we are now most likely using glockenspiel mallets. when mail is received and the signal interpreted by the phidget, each motor will rotate in sequence, thus swinging the mallets and hitting the chimes. We have managed to configure one of the motors so that when a certain angle of rotation is achieved, the direction of rotation is reversed, thereby preventing "double hits" caused by the chime swinging slightly.

Though at first glance more complicated than a single motor driving a screw, there were far too many variables with the previous design that would no doubt require endless amounts of tweaking, which at this stage in the semester, we really don;t have time for. Once we get one of the motors working perfectly, it will just be a case of copy and paste. We have already constructed a shelf on which the motors can be mounted, and from whichthe chimes can be hung. I found that by threading fishing line through the length of the chimes and tying off at a certain point, it was possible to suspend them without drilling holes through the top, which apart from being a little tricky (not much of a metal-worker me) may well have affected the overall tone of the chimes.

In the next week we hope to track down some appropriate mallets for the chimes (that's my job) and get all four motors working and mounted. We're also constructing a small section of wall on which to hang the final receiver for the presentation. The slightly sub-standard mailbox we built will be getting its gaps sealed up and a much needed coat of paint. It's then just a matter of installing the sensor and arduino inside.

Provided we can get all of this done, we are also hoping to incorporate a flashing LED light array into the clock face, adding a more visual signifier that mail has been delivered. More on that as events unfurl.

Bloggery obligation fulfilled, methinks. Time for Tea!

Cheerio.