I have converted the tie ups on my Macomber loom to polyester ones. I had 2 marks on the cords and for my current project I used the higher mark for the tie up. After about 10 inches of weaving the warp threads start to break one by one, sometimes two at a time, mostly on the edges. I removed (trashed) the first warp after hours of replacing ends and not solving the problem. The new warp was very carefully wound, threaded, etc. and still the breaking occurs. Could it be the extra height the shafts are raised? They are about 1/2 inch higher than the Macomber hooks raise them. I hope this is all clear. Thanks.