Tuesday, August 9, 2016

Save the Clock Tower!!

I am way behind on posting recent projects...and by recent I mean last Halloween. One of my friends goes all out for his annual Halloween party, there is always a theme and some elaborate prop. A couple of years ago there was a pirate theme so he built a partial pirate ship in his garage.

The theme for last Halloween was Back to the Future and the prop was going to be a large clock tower. I volunteered to build a clock motor out of an EV3.  The goals were:
  • Run until 10:04 and then freeze
  • Signal an arduino to trigger a lightning strike (white rope lights)
  • After five minutes of sitting at 10:04 start back up but spin extra fast so that we get back to 10:04 in 15 minutes
I found a pretty cool analog clock design online. It used technic parts and the instructions were only a few bucks. The gear ratios are such that for every full rotation of the long hand the short hand makes 1/12 of a rotation. Here is a test run of the clock being driven by a power functions motor.

And the finished clock tower with a lightning strike at 10:04