JUKI lbh-1790 series Engineer's Manual page 15

Adjustment Procedures
1. Fix knife bar rotary stopper 3 and the setscrew of thrust collar
4 (from the left side of the machine arm) so that when moving
knife bar 1 up or down, it moves smoothly and there is no
rotary play at knife bar base 2.
(Caution) When moving knife bar 1 up or down, check that
there is a sufficient clearance between square block
5 and knife bar rotary stopper 3 both at upper
and lower positions.
Adjustment Procedures
When sharpening knife 1 or replacing it with a new one 1, perform
as follows.
1. Loosen knife setscrew 2. Knife 1 can be simply removed
together with the washer.
2. Adjust so that the distance from knife 1 and the top surface of
the throat plate is 1 to 2mm when lightly lowering the knife bar
by hand as shown in the figure. Then tighten it with the washer
without fail.
When the cloth cutting knife 1 you have is indicated by inch, set
the cloth cutting length (knife size) to mm indication referring to
the inch / mm conversion table.
Results of Improper Adjustment
™ When the rotary play is large,
the cloth cutting knife may
interfere with the throat plate.
This case is very dangerous.
So, be careful.
Results of Improper Adjustment
10
− −