There have been a number of questions/comments on WeaveTech recently about sectional warping. So, it is not surprising that there have been a number of queries about sectional warping on the J-*s. While we have had relatively little difficulty winding sectional warp on our J-comp (aside from the problems of windus interruptus), there is one problem inherent to the J-* that I think we have now solved, so I am sharing it with y'all.
The problem is that when one loosens the steel ring on the shaft in order to slide the warp beam away from the worm in order to disengage it, there is nothing to hold it on that lateral position on the shaft. As a result it can slide back and forth about an inch, which is sufficient to thoroughly screw up the allignment between the tension box and the beam.
The solution: Take a piece of wood, none of the dimensions are critical and only one is a little fussy, (mine is 3 1/4" x 1 1/2" x 1 3/16") only the last dimension needs to be controlled between 7/8" and 1 1/4", the rest can be within 3/4" or more, but be sure that it is long enough that if it is loose on the shaft, it rests upside down on the worm. Using a 3/4" cylindrical router, cut a slot all the way through on the 3 1/4 x 1 1/2 face, going about 1/2 way up the block. (The cut is, therefore, 1 3/16 deep.)
Loosen the ring holding the beam against the work and slide the beam all the way to the other end. Set your block so that the routed slot fits over the shaft holding the worm gear and slide the beam back until it snugs up against your block. Tighten the retaining ring at the other end. The block should be in firmly but easily removable with your fingers. Now, when you want to wind, slide the beam over, drop the block onto the shaft and the beam can no longer slide about; it will stay put. Lift the block out, slide the beam back over onto the worm, and the beam is locked.
Works like a charm; pictures on our web site under J-made archive #17.
Cheers,
Tom.
Beam Shaft Spacer
