I've been facinated by Dave's PVC loom ever since I stumbled acrosst it. My initial reaction was 'What a wonderful idea!' A reaction that remains. That said I decided to construct a virtual version as a 3D CAD model. Shortly after I began I reverted to form (life long tinkerer) and began thinking about possible improvements to the original design. So far I've managed front and rear ratchet and pawl additions and am working on warp beam flanges. I admit to enjoying loom design as much if not more than weaving and working with PVC and 3D printing is increadibly satisfying. Here is a link to a Pinterest board that documents what has been done (out of date of course!): https://www.pinterest.com/hughmyers75/a-pvc-loom-improved-upon/ and an image of progress so far: 
I'm going to begin speculation about the castle next and retrieve my copy of the Hindson book and LH's book on draw looms just for grins. While I like advanced technology I also like the idea of small say table-top or slightly larger. I'm mostly in this to see how far I can push the idea of PVC and 3D printing when it comes to loom design. I also fully support the notion of Open Source when it comes to Make style projects like this. I think that what I'm looking for on Weavolution is feed-back, so fire away! :)