Hi Macomber Groupies-I recently bought my fourth B style Macomber and as I was setting it up, realized that the harnesses were hanging really low.  It resulted in me measuring the chains on all of my Macombers and I'm realizing that the one that has the shortest chain (ten links in a flat chain) works the best...the warp sits right on the shuttle race and when I tighten the warp and lift up the harnesses, everything stays right where it should be.  With the two looms that have 11 link chains, the bottom of warp will tend to "ride up" when it is tight and the shed is open.  The harnesses at rest are sitting slightly below the level of the shuttle race.  I'm thinking that I should shorten the chains.  Does anyone have any experience with this?  Would longer chains cause the bottom of the shed to rise up when the tension is tightened?  Thanks.

Comments

Wed, 04/18/2012 - 00:31

mneligh

Please correct me if I'm wrong, Michael, but I believe that under normal circumstances the bottom of the warp should be just below the shuttle race on a closed shed.  When using an extremely tight tension, I have heard, it may be necessary to move the chain up 1-2 links on the hook, with the understandinging that you may have to lengthen it after that piece is finished.

If you look at the warp with moderate tension on a closed shed, you'll see that the lowest point of the warp is where it passes through the heddle.  As you tighten it, the warp approaches a straight line, which may involve creating slack in the chains.  The beater has 2 slots, one deeper than the other, that allow you to raise or lower the shuttle race accordinging.

That's normal operation.  I'm thinking, though, that something else is causing your harnesses and hence the bottom of your shed to rise up.  I've seen this happen when the sett is very close and high friction, like woolen repp weave.  One cure is to weight the harnesses.  (Did you replace the heddles or have very few heddles on the problem harnesses?).  My cure has been to strum the harnesses every time I advance the warp so they swing separately from one another for a moment.

Try the strumming, check the beater position, and see if backing off the tension causes the problem to go away.

Wed, 04/18/2012 - 17:05

Michael White

Let me start by saying we have one Macomber with one chain link removed. Cheryl weaves with a lot of silk and the extra tension caused by the lower heddle height was a problem. To me a loom is a tool and if you have to adjust the number of links to make your loom work the way you want it to, go for it.

What said, as was stated above you have two slots in the beater legs and, some of you may not know this, the beater sits on a cam. The cam can be adjusted to raise or lower the whole beater frame. Sometimes the cams get out of wack. If you notice the heddle frames are not even with the beater; it may not be the frames out of adjustment but the beater cams. You can measure the height of frames from both sizes if they are even, measure the height of the beater to the castle cross frame and adjust the cam with a wrench. Sometimes when the cam is out of adjustment it will cause one side of the beater to pull away from the castle frame letting you think the beater in bent.

Michael