Having some free time and some interest here (I'm a full roller) I decided to see what I could find via Internet searching... I looked at full roller drill specs of many popular brands (roto grip, brunswick, storm, dv8, wiki, ...) and I found some interesting points of discussion, some minor conflicting info but mostly clear enough that I can draw some conclusions (please correct me if you know I'm wrong here)
ball should have 3" to 4" PIN
PAP is not used or considered in full roller drill
Asymmetrical and Symmetrical balls are nearly the same drill
CG is commonly positioned at mid position on finger center line (on the track)
PIN at 7 o'clock position to CG gives strongest hook potential (core full potential)
PIN at 9 o'clock position to CG gives medium hook potential
PIN at 11 o'clock position to CG gives weak hook potential
PIN out is generally 3-3/8" from track at 90 deg
Moving CG up to finger area, keeping 3-3/8" PIN out, gives more mid-lane hook and keeps back end
pulling PIN in to 1-1/4" from track at 90deg and keeping CG in finger area gives length and back end
Some of the brands/sources give measurements from PIN, rather than from CG, but the math works out to be the same thing. An interesting study on wiki moved the CG right for standard and right & up for aggressive.
I didn't find anything on drilling a spare ball. I guess I can get a weak core pearl and dill it weak _or_ learn how to release a 3/4 roller for my spare.
Brad
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