Visa, Visa Delta, Visa Electron, MasterCard, Maestro

About The Clock

The clock on the front page is a fully functional working model. It is driven by a 240 volt synchronous motor, which gives a handy 1RPM clockwise output.

There are 7 separate output movements, all on the front face, as follows :-

  1. Second Hand - Lower Centre. Direct drive from the motor via rubber sleeve, acting as a clutch.
  2. Minute Hand - Centre. 60:1 (5x2x2x3) ratio from the second hand.
  3. Hour Hand - Centre. 12:1 (3x4) ratio to minute hand.
  4. Tide Phase Indicator - Centre, below main hands. Driven from the 1RPM second hand, using a differential to give 186.666:1, then multiplied by 4 to give 746.666:1. Time between high tides is 745 minutes, so this is accurate to 0.2237%
  5. Moon Phase - Centre, above main hands. Driven from the hour hand, using a differential to give 199.5:1, divided by 15/50 to give 59.85:1. Time between moon phases is 29.53 days or 59.06 half days. This is accurate to 1.2%
  6. Day of Week - Right. An intermittent drive from the hour hand divided by 2 using a 28 Tooth Sprocket with a centre fork indexing 2 teeth per day. Geared up by 2:1 to give a 7:1 ratio for day of week dial.
  7. Date - Left. An intermittent drive from the hour hand divided by 2 engaging a peg into one tooth of the plastic sprocket. The dates are on 31 sections of caterpillar track.

All constructed from standard Meccano parts, except the polystyrene ball, paper for date, days and tide phase, and of course, the synchronous motor.

Clock