GearHeads Forum

Nice work Bill, always wondered how they did that 4 side clock face, thanks for sharing.


Cheers
Bob

Hi Bob

The attached photos show the inside of the clock tower.  The 4-way bevel gear split is kind of unusual..the top gear is 60T and the  mating gears are 50T.  This reverses the 50T-60T gearing in the clock room.  Our guess is that the first 50T-60T reduction may have been used to bump up the torque a bit prior to the chain of bevel gears to the tower.  When the clock was last running in early 2010 the wear and buildup of friction had reduced operations to a single dial.  Input /Output of each bevel set is driven via universal joints.

The current installation is different from where the clock came from.  The clock mechanism was probably mounted directly below the 4-way split which would have greatly reduced frictional losses in the drive train.

The second two jpgs show one of the motion works.  The input to the motion works is the minute shaft.  At the time we examined one of the motion works I did not have time to document the gear thicknesses, # of teeth, or gear diameters.  What I modeled in Gearotics was my best estimate of the gear ratios and sizes.

My goal of the simulations is to document the mechanical details of the entire clock.

Bill

Bill:

As of next version the bevel reversal will no longer need to be relinked to rotate properly.


Thx
Art

Hi Art

It will be interesting to see if the  fix to the bevel gear reversal also corrects the other anomaly in the rotation rate calculations.

I suspect that I may have to undo the links in my tower clock sim.  But at least I've been practicing with linkages.

Bill