above ground pool reel

we're installing a solar blanket roller system outside of our AG pool at one of the ends. We have a 18' AG round pool. We've placed 2 6X6 posts at one end and attached the saddles and aluminum roller. How far in should we place the straps on the blanket to roll up successfully? I did try to access one forum's post to view her jpeg images but was unable to access them. (huskerfan) posted 07-14-2011.
thanks

I made the pictures visible to all: http://www.poolforum.com/pf2/showthread.php/13103

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