Even though my "system" looks oh so simple in the detailed photographs... There IS some science involved in the form of an accurate ruler or tape measure. One "should" lay their chains out ever so carefully
on the floor and compare them to the scales on a good tape measure or ruler. Laid out flat with all the crosschains centered in their corresponding side link attachment points merely measure the center of the end of one crosslink to the very same point on the next crosslink. This measurement is your "Slot Spacing Guide Number" (SSGN).
One should try to repeat the SSGN as often as possible on the flat board for a more professional looking finished product. (See previously posted pictures for professional appearing finished product for comparison.) The further your chains are spaced such as "3 link" and "4 link" spacings will require wider (lengthwise) lugs to support the tire properly and allow the chains to slide though.
Redundant I know, but this review might save someone a few days of wasted effort and utter disappointment with a failed or worse yet, dangerously flimsy finished product.
EDIT: IMPORTANT! Before driving tractor onto block(s), lay chains out into spacers.
Edited by HydroHarold, November 23, 2012 - 09:42 PM.