Originally Posted by Twisted Quilter
I was suppose to be making a 12 1/2" block unfinished,
Is this for something you are doing for yourself or is it for a swap?
If it is for yourself, then you just have to make sure that your blocks will fit together and 12 1/4 may be sufficient.
If it is for a swap, I hate to say but it needs to be 12 1/2.
I've been sewing for a while and the row robin I joined gave me huge heartburn about the stupid block size. For a few days I could not sew a 12 1/2" block to save my soul.
Keep on trying - it will happen and you will get a feel for your sewing machine feet.