I have a Harrisville 36″ 8-shaft loom. I am weaving with 484 ends of 30/2 bleached linen on four shafts. I warp from front to back. My husband helped wind the linen onto the back beam and I thought I applied enough pressure to wind with an even tension onto the beam (he turned the beam while I held the warp). Heavy Kraft paper was wound between the layers of linen on the beam.
I have two problems:
#1. The edges of the warp are looser on the left side of the loom, so I need to place a small ruler under them on the beam to tighten the warp threads there. Did I not hold tension evenly on the left edge when we were beaming the warp?
#2. When I finish weaving for the day, I tap the brake lever to loosen the tension so the linen is not tensioned all night. When I do this, the warp behind the shafts severely droops, looking like a hammock. I am sure this also changes the tension that was achieved when winding onto the back beam. I have checked the brake assembly and it seems to be correct. Short of holding onto the back beam before I tap the brake pedal, what can I do to not have the back beam release too far?
#1 My guess is that the crank that turns the beam is on the right side of the loom. You are holding the warp under tension as your husband turns the crank. There is enough torque in the beam that the crank end of the beam is turning through a slightly smaller circumference than the opposite end of the beam. This is one reason that I’m not a fan of holding a warp under tension when someone else turns the beam. Another consequence of beaming this way can also be that the edges of the warp go on a bit tighter than the center because of the difference in the angle that the threads on the edges pass through from the threads in the center. For both of these reasons, I do the beaming alone, turning the crank and then coming to the front of the loom and pulling tightly on small bouts of warp (about 2″ warp width each). At this point, with linen, especially, I would recommend rebeaming rather than trying to separately tension the looser threads.
#2 In general, unless I’m going to leave the warp for quite some time (days), I don’t release the tension between weaving sessions. It really doesn’t do the linen any harm to remain under tension (and the loom should be able to withstand remaining under tension). If you do need to loosen it, you should get up and hold the crank as you tap the brake pedal to prevent excessive unwinding. (The excessive unwinding, however, shouldn’t really change the overall warp tension on the beam.)