Singer 758 adjustments for needle position and stich width
Found this below that may help confirm timing? As for the zig zag one thought is to check for end play in the upper shaft. At the left hand end of the shaft (under the top cover) there is an white plastic "bushing" with one slotted screw - this can be adjusted to take up the slack. It is possible that this bushing is split by the screw which may make it come out of adjustment. Check the other collars on this shaft are tight (hex) - by the belt and near the drive gear. P.S. double check the zig-zag cam is in the correct position (set to straight sew - centre position to install the cam - check instructions).
Turn the handwheel towards you until the needle is in the
lowest position and observe two lines on the needle bar at the place
where it comes out of the machine. You have to see these lines. When
you find those, you have to tilt the machine on its back and you will
see that on the right hand side there is a belt coming down onto a gear
like piece on the timing shaft. Move your eyes to the left and the next
thing that you will see is a large round gear on the feed shaft. Now
that we have determined the difference between the feed shaft and the
timing shaft, follow the feed shaft to the left and there will be a
small metal piece there with two metal screws on it. Next to that to
the left is a stationary metal peice that has a bump on it. You must
see these two things to adjust your machine.
Now, to determine
if your machine is out of time, turn the handwheel towards you (always
turn it towards you) until the needle is in the lowest postion again.
Observe the two lines on the needle bar, turn the handwheel toward you
until the bottom line goes in the exact place where the top line was.
Now look at the needle and hook. The hook should be directly behind the
needle. If it is not, we go back to the bottom of the machine on the
gear like metal piece that the belt rides on and loosen the two screws
that are in the piece. Now if you will remember, this is on the timing
shaft. When these two screws are loose, the hook will become moveable.
Place the tip of the hook directly behind the needle without moving the
needle bar (remember that the needle bars bottom line was placed where
the top line was). When you have accomplished this, tighten the screws
on the belt gear.
Now you have to determine whether the feed
is in time. Again, place the needle in the lowest postion, rise the low
line to where the top line was, and see if the line on the feed shaft
is directly next to the bump on the stationary metal piece. If not,
without moving the handwheel at all (because it must stay in this
position to time it), loosen the two screws on the feed shaft piece and
align the two lines together. Then tighten the two screws, make a few
rotations with the handwheel, and again, put the needle in its lowest
position and rise the bottom line to where the top line was. Inspect
the two lines on the feed shaft and the hook behind the needle.
these did not stay in adjustment, re-do the entire process, but be more
careful not to move the handwheel when making the tightening
adjustment. If you re-do this and it still does not stay in adjustment,
you need to replace your timing belt,
Jan 01, 2009 |