Sandra asked for photos of my setup, so here they are:
This photo shows the weight (30 lbs of iron plates) and the counterweight (3 lbs of iron bars). The cord connecting them, which you can’t see, makes one full loop around the warp beam. Two loops are what Kati Reeder Meek recommends in her book, but I couldn’t fit two full loops in the space I had, with the rope I was using, so I used one. It’s pretty rough rope so it seemed to work quite well.
(30 pounds times two weights = 60 pounds turns out to be WAY too much weight, by the way – I now use only 10 lbs for a 24″ warp, with a 1 lb counterweight, and it works just fine.)
How this works:
- The rope double-wrapped around the beam produces a lot of friction. It doesn’t slip easily.
- Therefore, as long as you keep the rope taut, even a small counterweight can keep the rope from sliding around the beam. This is why the big weight doesn’t fall down.
- The big weight, via the rope, pulls down on the warp beam and makes it rotate. The rotation, if you have set things up correctly, pulls the warp back towards the back beam. This puts tension on the warp.
- Advancing the warp pulls the big weight up, and brings the little weight down.
- The aha! moment: when the little weight reaches the floor, it sits on the floor and the tension on the rope is released.
- Since the tension is released, the friction of the rope around the warp beam drops, allowing the big weight to slide down.
- As the big weight descends, the little weight ascends, until it starts to put tension on the rope again.
- The rope becomes taut, friction increases, and the big weight stops descending.
There are a couple advantages to the live-weight system, so far as I know:
- Even tension. Always the same amount of weight pulling back on the warp. With most brake/ratchet systems, there’s always some unevenness as you advance the warp.
- Less stress on the warp threads (at least with a jack loom). The warp threads are no longer attached to immovable objects at both ends, so they don’t have to stretch as you raise the warp. Instead, as you raise the warp, the warp beam rolls slightly forward to accommodate, reducing the stress on the warp threads.
- Automatic tensioning. The thing self-adjusts as you weave (see steps 5-8), meaning you never have to touch it the entire time you’re weaving. In theory at least, It Just Works. No fiddling with a brake release. You just advance the warp. That’s all.
Here’s a second photo showing the weights on both sides. Kati, in her book, uses a barbell, but since the average barbell is 5 feet long (7 for Olympic weights) and I don’t have that much space, I simply hung one set of weights on either end of the warp beam.
The film canisters and broken threads are, um, there purely for decorative purposes. Decorative. Yeah, that’s the ticket. 🙂