Thread Tension Release Lever; Setting The Thread Tension Knob - Husqvarna 6690 Manual

The upper thread tension release
Requirements
The lever (6/33), which gets its impulse from the
presser bar lifter, should release the pressure on
the thread tension washers, via release arm (6/19),
when the presser bar is lifted, but must not touch
the release arm (6/19) when the presser bar is lowered.
Adjustment
Lower the presser foot. Turn the eccentric (6/9) until
the lever (6/33) is free from the release arm (6/19)
The clearance between the details should be as
little as possible.

Setting the thread tension knob

Requirements
When the index on the thread tension knob is level with
the red dot on the front plate, you should have the right
tension for proper thread take-up for normal sewing.
Adjustment
Turn the thread tension knob until the required tension
is obtained. Remove the front cover. The outer part
of the knob (6/22) should be drawn out and turned
until the red dot is right in front of the index. When in
this position push the outer part back again. Check
the knob, to make sure that the grades 0-10 can be
set at the index. If this is not possible, the thread
tension spring (6/18) must be exchanged or spacing
washers should be inserted.
Comments
The thread tension you have when the index is level
with the red dot on the front plate should only be
regarded as a general indication. When sewing
fabrics which are not of normal quality, and if
absolutely perfect stitching is necessary, the thread
tension should be adjusted according to the thread
and fabric.
Spare parts: See RA, page 6.
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