Hi,

I'm making the Weight Driven Brass Alarm Clock and am starting to cut the wheels. I made my own Modular Dividing Head from a series in either Home Shop Machinist or Machinist's Workshop. It's like the Universal Dividing Head ? that uses a worm wheel and change gears plus an index plate for indirect dividing. After trying to cut the 48t wheel and discovering that my 36 hole circle only has 35 holes( homemade plate) I decided to check the hole spacing with digital calipers. My hole spaces on the other two circles(22 and 25 )are'nt very consistent.Up to about 10 thou variation.

So here are my questions. I thought I've read that even if the hole spacing on the index plate is'nt perfect the mechanism of transmitting the division request, so to speak, through the worm gear somehow produces a much lesser error in the in the finished tooth or gear ?

And even if your clock wheels are'nt perfect does'nt the act of depthing the wheels compensate for any imperfections? How does an imperfect wheel affect the operation of the clock? Two hundred years ago the equiptment available to clockmakers was much cruder than it is now yet they were still able to produce workable clocks.

Thanks ,

Mark