Tuesday, March 20, 2018

Metronome flasher

Here is a circuit Edwin built this morning.  It's not complicated, but it is clever...

He figured out that the metal mechanical parts of the metronome are all in contact with one another.  He attached a wire to the winding knob, which was therefore attached to the pendulum.  By aligning the pendulum carefully with a snap circuits wire, the metronome intermittently completes the circuit.

Here is a video of it in action!

Sunday, March 4, 2018

Fly for small tent (part 2)

Based on a guy line test fit, guying at the corners is mostly sufficient.

However, the long sides have a tendency to touch the side of the tent.  Adding guys at the middle of each of the long sides seems to resolve this issue.  The only subtlety is the door; the guy line should attach to the left side of the door zipper (when facing the tent) since I'm right-handed.

Parts needed
  • 6 stakes
  • 6 guy lines each about 2 feet long
  • 4 corner attachments
  • 2 side attachments for the long sides
  • zipper pull
The top of the tent -- where all the seams come together -- is something of a mess.  To fix that, I sewed a rectangular patch at the top.

The six guy point attachments are made from siezed loops of 1/8" braided nylon cord.

These loops are sewn directly into the corners...

... the middle of the back ...

... and the left side of the zipper.

The zipper pull is a bit short, so I added a lanyard.  The lanyard starts as 2 feet of 1/8" nylon cord.

Here is the completed lanyard, which is tied directly onto the zipper pull.

Finally, I added guy lines and set the tent up.  Once up, I sealed the seams!