What I have sent to be posted in the drop box is a scan
 of index tables from L-W Chuck CO. for their dividing heads.
One chart show divisions for the 11" dividing head. One shows 
the divisions for 6.5 to 11" dividing head. The other two are 
for cutting leads for spirial milling for the 11" dividing head.
I don't see any reason why this information wouldn't be the 
same for any 40 to 1 index head with spiral milliing ability. 
The jpg pictures are titled indexlw1, indexlw2, for leads is
indlead1 and indlead2

Richard Weich