HQ Infinity Service Manual
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3.
Lower the needle bar to its lowest position
(
bottom dead center
), or to where the second
screw is accessible.
4. Use a 2.5mm hex tool to loosen the set screw on the counter weight crank.
5.
Adjust the reciprocating counterweight to be at its top position in the cylinder and flat on top when
the needle bar is at its lowest position.
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IMPORTANT
: Take care not to move the counterweight crank to the left or right on the main shaft,
creating a bind in the piston.
6.
Tighten the set screw, rotate the hand wheel until the needle bar is at top dead center and tighten
the other set screw.
7. Check by rotating the hand wheel to confirm the machine turns freely, the reciprocating counter
weight does not bind, and that there is no unnecessary noise.
8.
Check that both set screws are fully tightened.
11. Belt Tension
Motor to Hook Shaft Drive Belt Tension
To check motor to hook shaft drive belt tension
The motor belt should be adjusted to have immediate transfer of motion from the motor to the hook
shaft without placing any undue pressure onto the motor shaft bearings or make the machine hand wheel
hard to turn. When properly adjusted, the machine will have good response for accurate stitching while
preventing undue strain on the motor bearings, excess belt noise, or machine tightness. Check that the belt
has good engagement, without being too loose or too tight. If it is too loose, the belt will have play in the
pulley teeth if one pulley is blocked while trying to turn the other. If it is too tight, the machine belts will be
louder and the machine hand wheel harder to turn. This will make the machine less responsive.