Can I weave a shaft loom project on my rigid heddle loom?planning projects
There’s lots of 4 shaft weaving projects out there, and you may have come across one you want to weave. But can you weave it on your rigid heddle loom?
Like many things, it depends! You can of course always be inspired by a project and use it as a jumping off point on your planning - but here I’m talking about weaving a project or pattern you've found in a book, magazine, or purchased online or as part of a kit, without making changes that require extra calculations or sampling - weaving it pretty much as written.
If you’re a beginner or otherwise just looking for a project you can follow easily, my advice is to stick to patterns written for rigid heddle looms. The language used to describe shaft loom projects can be a bit different, and some things that are easy on one style of loom are harder on another, and this goes both ways! You have to understand both worlds enough to understand the differences, especially if you also want to stick with direct warping. There are many wonderful patterns and books out there for rigid heddle weavers, that will be much easier to follow.
If you are a little more experienced and want to give it a go, the biggest and most common obstacle is sett. Shaft looms have more options for sett, and many projects designed for shaft looms will use a sett that can’t be done exactly on a rigid heddle loom, either because it's "in between" your sett options, or just too fine for a rigid heddle loom. However, there are plenty of shaft loom projects that are at a reasonable sett for a rigid heddle loom, particularly with multi heddle techniques.
So what setts can you do? It depends on the chosen structure, as well as your available heddles (which will vary a bit by loom brand). In rigid heddle land, we talk about density: how many threads go through how many dents (holes & slots) to achieve the threading. Most single heddle weaves are done using 100% density: 1 thread in each hole and slot, so the ends per inch (EPI) of the sett is the dents per inch (DPI) of the heddle, while basketweave is typically done at 200% density, or 2 threads per hole and slot. With 2 heddles, you can do any 4 shaft straight draw - which includes plain weave, basketweave, and many twills, and others, at 200% density, using the so called "standard" threading.
For a more concrete example, lets say you have all of the Schacht heddle sizes available. You can then match the heddles and do 5, 8, 10, 12 at 100% density, and 10, 16, 20, and 24 at 200% density. You could also do a weave at 50% density, by skipping every 2nd pair of hole and slot, giving you 2.5, 4, 5, and 6; this most often comes up with weft faced weaves. That will cover many shaft loom projects, but some will use setts like 18 and 22 that you can't do. A difference of 2 EPI will make a significant difference to the width of the finished item and have an impact on the feel of the fabric, both of which may lead you to wanting to make adjustments and/or sample. And if a project is sett at, say, 32 EPI, that's just too fine for most structures on a rigid heddle loom.
Other structures including point twills have different options, like 150%, but I won't go into those here - check out this post by Liz Gipson if you want to dive deeper. But in short, you often have a couple different ways of threading a structure to be more or less dense, but not an unlimited number of ways.
Some other potential pitfalls are if the project requires too long of a warp, or if it requires a heavy beat or especially high tension. Other things that could cause issues are cramming and spacing of the warp, really warp faced weaves, and mixing structures - the 2 heddle standard threading is more flexible than straight draw, but some others might not be! Finally, shaft loom weavers often work with yarns with very little stretch, while these can be more difficult to work with a rigid heddle loom - 8/2 cotton tea towels at 20 EPI are doable on both looms, but, require double heddle techniques (or basketweave) and a lot of fussing with tension on a rigid heddle loom. These kinds of things are a little hard to describe succinctly, but, in short, if something about the project is very different from something you know you can do on your rigid heddle loom, it might not be the right one to try adapting.
So - a balanced-ish plain weave project at 12 EPI? Easy! At 18 EPI? Needs some adaptation as you'll need to change the sett considerably. At 20? You'll need to use 2 heddles but it's totally doable. A 6 yard long, thick, rug requiring high tension? Maybe not the project to try on rigid heddle.
You can weave some shaft loom projects on a rigid heddle loom more or less as is, but, just because something is plain weave, or another structure that you know how to do, doesn’t mean you can translate the project exactly to a rigid heddle loom!