This is the second part in a series of blog posts talking about the differences between two AVL production dobby looms. I'm showing what the different mechanisms look like and talking about how these differences affect production weaving work. If you're interested in weaving for a living, you might like to stay tuned and learn what you'll want to know when choosing a production loom.
The beater attachment is so important that AVL lists it in their product descriptions. I don't have a specific recommendation for which is better. I think it's a matter of personal preference. An overhead beater is MUCH more stable. It has two arms that come off the back of it and attach to a steel rod that runs through the center of the loom. This causes the two sides move parallel to each other. It's very difficult, if not impossible, to beat an angled fell line.
A bottom swing beater works like those on most smaller looms. The difficulty with it is that this loom is much wider than most home looms. With just the reed and race to stabilize it, this beater flexes quite a bit as it is used. The two sides have no mechanism to keep them parallel. This is amplified by the fact that one side has the auto-advance mechanism attached. It needs to be pushed forward, cranking the breast beam and pulling the whole warp forward a little with each beat. This means that the left side really wants to lag a lot from the right side. It takes work and concentration to get both sides of the beater to contact the bumpers at the same time without banging. But it can be done and eventually feels natural.
There is one thing that affects the actual daily work of weaving and leads me toward recommending it. A bottom swing beater will stay where you stop it. If it's forward when you stop, it stays forward. If it's back, it stays back. With a hanging beater, gravity wants it to rest about halfway between the fell line and the back bumper. There is a latch on the left to allow you to latch it back, but there's no way to latch it forward.
Apart from this minor difference, I really do think that you will be happy with whichever beater style you choose. After a little experience, they each become completely natural.
PS: I lied about today's post being epic. I was confused. It's the flyshuttle post that will require a lot of description. And that post is coming soon. Stay tuned!