GearHeads Corner

Hi Art,
I'm building a clock in which the weight drive is via a ball chain.  The chain has 100 balls in 24.5 inches.  I want the balls to engage a cage wheel.  The issue I have is how to calculate the DP so that the ball chain engages perfectly. 
Currently I am making cages the are close but no cigar.  The chain having no stretch is therefore unforgiving and is actually a victim of cumulative error causing a skip every so often.

Hope you can help.

If i'm not clear you can see my problem in the attached photo.

Hi John:

    The module should be the distance between center of the beads. It may be the size of the holes may not be correct at that setting so
you may have to enlarge them slightly but to sync the balls, the distance between them should be set to the module.

Art

 

John:

  I notice your using the rod wheel to hold the chain, I suggest you use the spur gear form the cages instead, by shaving off the tips of
the spur you should be left with just roots set to the correct module so the balls fall into the roots. By using the cage gear you are
actually getting a distance between balls determined by the diameter of the rods as well as their module.  Thats makes it a hard
calculation...


Art

I discovered that the epicycloidal gears do non respond to either the tooth width nor the stub settings.  Is that right or am I doing something wrong?  The flat sided shape of epicycloidal teeth looks like it might work best, but the tooth width would have to be reduced I think.

Thanks for the help I?m a lot closer

John