Ribber problems... Legare 400 using 72 cylinder and 36 ribber setup in 1x1 rib. Indiscriminate problems with previous row stitches (noted before but not solved). Machine timed. Yarn carrier correct height. Normal weights. Ribber needles misbehaving swapped out and later in without repeat problems. Same needles not misbehaving predictably.
SOLUTION:
-replaced timing screw with better fitting cylinder screw, nut and tension washer (won’t undo itself with use)
-lowered ribber a little
-re-adjusted yarn carrier to cylinder and ribber ensuring horizontal ribber needles cleared yarn carrier while yarn feeding was correct.
-re-timed machine 2-3 times over all.
-used sock yarn weight scrap for project specific new style of cuff down start
-slow cranked 10 rows to identify final 8 ribber needles trying to pull yarn into ribber slots
Problems noted (hindsight is always 20/20):
-prior ribbed stitches were getting hung up on horizontal latches not clearing off to form new stitch.
-some ribber stitches were being pulled into the machine with open latches staying open
-ribber stitch latch amputations
-dropped cylinder needle stitches, incomplete ribber needle stitches and dropped ribber needle stitches
-timing screw noted loose with securing nut undone
It hadn't occurred to me to use my camera phone and look under the ribber from the floor up to see why a ribber stitch was not completing/coming off the horizontal needle into the worked piece. A couple camera shots at re-start number 8 or 12 (?) noted the worked 'webbing' easily completely disintegrates with dropped stitches causing no material to pull down new stitches. Basically it all came down to timing and naughty needles.