I just finished threading my reed putting 4 warp threads per dent. When I started to beam the warp it was a mess, there were so many tangles to comb out. Is there a trick for preventing the tangles when warping multiple yarns per dent? Would the trick be in the way the warp threads are measured?
I have more or less answered this question before, but it is worth answering again. If you warp front to back and put several ends in a dent, even if you wound the threads singly with an individual cross, unless the order in which they were wound is the same as the order in which they go through the heddles, twisting can occur between the reed and heddles. If you wound all 4 threads together putting all 4 in the cross together, the twisting would be even worse. My rule of thumb is not to worry if I have 2 ends in a dent and am using a smooth, non-twisting (inert) yarn. But otherwise, I "transfer the cross" before threading.
For those of you who can't picture all of this: When you warp front to back, you sley the reed first, and even if you have lease sticks in the cross when you sley the reed, the lease sticks come out after sleying. If they were left in, they would be on the wrong side of the reed to be used for threading. You would then thread, taking the ends from each dent in order. If only one thread is in each dent, the threading order will be exactly the way the threads were wound on the warping board. If there are 2 threads in a dent, you choose one of them. You might not choose them in the exact same order in which they were wound, but chances are good they won't be twisted around each other or stick together unless they are over-twisted or sticky yarns. If there are 3 threads in a dent, the possibility of twisting (between the reed and the heddles) becomes greater.
Since beaming is the part of warping I like least (second to counting and moving heddles), I do whatever I can to minimize this twisting. It is also never good to have to do any combing; if you start combing the threads to compensate for twisting, you will comb them for their entire length and beaming will take forever. So, if I have multiple threads in a dent I do what is called "transfer the cross": I wind the warp with a one-and-one cross. Then, I sley the reed, leaving the lease sticks in the warp. After the reed is sleyed, I turn the lease stick closest to the reed on edge to open a shed. I stick a third lease stick into that opening on the other side of the reed. Then I take the first stick out and move the other lease stick that was in original cross up to the reed and turn it on edge to open a shed. I then put the first lease stick into that opening on the other side of the reed.
The irritating part of this task is that you have to have tension on both sides of the reed to make the openings, so if another person is there, they can help. Otherwise, I secure the warp to the front apron rod with ties so that I can put tension on the ends dangling from the reed to make the openings. All of this is painful, but not nearly as painful as what you had to do. I do show the process in the video Warping Your Loom.
Hope this helps!