Sweet

 

fell is 4 inches from the breast beam

with beater forward up against the fell, the web is just touching the shuttle race

with the fell now 3 inches from the breast beam...

the beater is now 'scraping' across the web as the web needs to bend to get by the shuttle race

There is talk of 'sweet spots' and how important to keep the fell within the 'sweet spot' between the breast beam and the beater.

On a loom like the Megado, it seems like there is a huge space between the breast beam and the beater - and there is.  That means that the sweet spot on the Megado is larger than most looms.

But!  It isn't as large as some people might think.

Generally I set the fell at about 4" from the breast beam because any closer and the beater begins to scrape against the web.  With this particular cloth that isn't a huge problem, but if I were weaving something less stable the beater can begin to shove the picks out of their proper alignment.

And unless you look underneath at your web, you might never see what was happening because it's all happening below, out of sight.  Until you do get to see the web when it comes off the loom, or you notice something peculiar on the cloth beam.

Likewise I tend to advance the fell when the fell is still a distance away from the beater, due to the tension forces on the warp.

What do I mean?  I've written about tension forces on the warp extensively in Stories from the Matrix, but essentially the closer the fell moves to the beater, the tighter the tension becomes, the more the weaver has to work to open the shed, even as the shed reduces in size.  Yes, even on the Megado, which has a 'floating' breast beam.

How do I know?  Because I pushed to see how far I could successfully weave before needing to advance the fell.  

Even so, the distance between the breast beam and beater is such that I can easily weave about 3" before I need to advance the fell, compared to *most* (not all) looms where the distance is between 1 and 2 inches, depending on the loom and how much distance there is between the breast and back beam and the position of the beater at 'rest' against the castle.

Recently I saw someone comment that the Louet floating breast beam means they don't have to adjust their tension.  Which isn't actually accurate.

What the floating breast beam does is to move slightly when the shed opens in order to keep the tension on *all* the warp threads more equal.

With a rising shed loom, the tendency is for the ends that are lifted to be under greater tension than those left down.  Louet has come up with some nifty engineering with reduces that tension inequality.

But the loom setting your tension for you?  Nope.  You still have to do that every time you advance the  warp.

The only exception to that is a loom with a live weight brake system.  Once the tension is set, it will remain the same throughout until you change something.  Even so, the 'live' weight may need to be adjusted as the circumference of the warp beam changes.  The larger the circumference, the more weight is needed to hold tension on the warp.  As that circumference reduces, the weight may need to be reduced.

As always...it depends...