My wife showed me some pictures of old Norwegian box looms and asked me to make something similar. The reason being that a back-strap loom can be impractical with small children running around.
As I am not much of a woodworker (I normally work in steel), I decided to design something that could be laser cut and then assembled with a minimum amount of work. This idea got away from me a bit and I ended up with the design below.
Once you have the laser cut materials, the loom can be made with the most basic of woodworking tools. All measurements are in mm, but none are so critical that they cannot be eyeballed.
A step by step guide and bill of materials can be found in the pdf.