I started a towel with 23.5 " , my broadest piece so far.
I was totally frustrated, the shuttle was diving under so many times what had never been a problem so far. I tried to optimize my movement with an empty shuttle, but the result was pretty poor and not reliable with normal tension.
By rewatching Episode 1.3.3, I noticed a wooden thing attached to the reet, a shuttle race as I found out. I had never paid attention to this and my Jane loom doesn't have one.
I made one by myself, the shuttle flies like a dream, but it is too wide and bumps into the cloth while beating what minimises my weaving distance to about 6cm. I will have to find a narrower solution at the hardware store.
Am I alone with this issue?
If your shuttle is diving that much you need to increase your warp tension. AND, check to see that your warp is going over the thread beam at the back and not coming into the heddles directly from the warp beam. This is not normal for a Jane loom unless you tension is too loose :) Hope this helps.