You might also consider building a version of Matteo Salusso's tubular rigid heddle loom.
His "educational loom", i.e. a loom which can be rigged for several different styles of weaving:
And a more traditional loom, using the rigid heddle:
In this second video, he's showing how quickly the loom can be dressed.
He also has videos on his channel showing warp weighted and frame loom versions, a portable version which he sets up on a stone bench in the town square, demonstrates using a library book for the structure of a loom (a cutting board or similar would work equally as well), etc. In one video, he even sets up a loom with leases for fancy pattern weaves (probably not really the long suit of this style of loom, but it does illustrate that such things can be done). The tubular heddle allows for crossing warp threads to effect certain types of patterns (similar to tablet weaving).
In the interest of full disclosure, I did try to make one of these, using my Pony brand hand miter box to cut the slits in a piece of scavenged plastic drain pipe, but wasn't quite successful. The edges of the slits were too rough - they would have abraded the warp, since the tubular heddle is the beater. I now have a better hand miter saw box (made by Millers Falls, though badged as Craftsman), and a small diameter wire wheel to use for deburring the slot edges, but I haven't gotten back to that project. Matteo seems to use plastic electrical conduit, cuts the slits with a chop saw, and deburrs with a wire brush:
Anyway, this is at least worth a thought, in your endeavor to make a loom.
I do have some loom plans in my electronic stash of stuff. I'll see what I can come up with.