one head sewing loose

dgeorge

90deg not 180

to set the distance between rotary hook tip and needle you must use No14(90)needle
rotate needle 90deg from normal position and move the rotary hook to have slide contact with needle.
hook point is 200 deg but depends model
timing means the point where rotary hook tip meet the needle(degrees) .
you can have for one head bad timing if rotary hook was moved from normal position (because bird nest,broken needle....)
is in Tajima book

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tehx maintenance guide