ok finished my round on twinrivers block. This is what came to me, dumb bunny. I 'borrowed' ok STole the instructions for our swap from the one run by dragonflynana. The trouble with this is while the 12.5" and 24.5 inch centers work with a 4.5 and a 6.5 round a 18.5" block does not. The block sizes going up do not divide into even blocks. so.. in an effort to make up for my not thinking this all through I added a border in the middle so that when the center now goes off to Teresa she can just 'whip' up a 4.5 inch round no troubles at all and same with Jaba when she gets it next.
if your having trouble getting your centers to work talk with me and maybe we can come up with a mathematical solution. (ha come to me , uh come to Jaba or tlambing first who am I kidding!) wil post pictures later or tomorrow at the latest I have to upload them all to facebook first so I can attach the web page to put them here.. pain in the rear. I want my windows xp back!