Bernina Record 930 Electronic User manual

Service Guide
Model 930
Sewconsult.com 2002
Div. Sewing Educational Warehouse

Table of Contents
Parts of your machine Page 1
Removing covers page 2 – 4
Cleaning and lubrication page 5 – 6
Adjusting bobbin tension page 7
Adjusting top tension page8
Hook timing page 9 – 10
930 service tips page 11 – 55
Troubleshooting guide page 56 – 60

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2
Tuning up your machine
There are three main points to a tune-up on a sewing machine.
-Cleaning and oiling
-Hook and feed timing
-Internal tension adjustment
Start by removing the covers on your machine.
DO NOT START ANY REPAIRS WITH OUT UNPLUGGING THE
MACHINE FROM THE WALL OUTLET

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5
Cleaning and lubrication
The best way to remove lint from the machine is with
compressed air. Blow all the lint from the machine. Remove all
lint from the gears and again from the bobbin area and feed
dogs.
When oiling your machine, make sure you use a good quality
oiler and clear sewing machine oil.
This type of oiler is good because it has an extendable
spout and only lets out small drops of oil. A drop of oil is the
amount of oil left on the tip of a needle if you dipped it in oil.
Once the covers are removed use compressed air to clean the
machine. Check for thread and lint in the needle bar area. Also
pay close attention to the hook area. Care of the hook area is
covered on the next page. Check the hook for burrs. Polish any
with fine sand paper. Be careful as the hook must be smooth on
all surfaces.
Oil all moving parts in the machine making sure to remove all
excess oil with a soft cloth.

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7
Adjusting Tensions
To check the bobbin tension, insert a bobbin wound
with medium weight thread into the bobbin case. Remove the
hook from the machine. Snap the bobbin case onto the hook.
Hold the hook and bobbin case by the bobbin thread and jerk
the thread once or twice. The bobbin and hook should move
down a bit. If the hook does not stop moving down the tension is
too loose. If the hook does not move the tension is too tight.
If the tension is too tight, turn the screw counterclockwise ¼
turn at a time and retest. If the tension is too loose, turn the
screw clockwise ¼ turn at a time and retest.
Continue to loosen or tighten the tension screw until the hook
only moves down about ½” when you jerk the thread.
It is rare that you have to adjust your bobbin tension. Mainly if
the tension spring was bent or for specialty sewing.

8
Top Tension
The top tension is controlled with the tension dial. Normal
tension is when the indicator is centered. After the bobbin
tension is set the tensions should balance in the center of the
fabric as shown.
If adjustment is required, sew a test and turn the top tension dial
until the right tension is achieved. Open the top cover and locate
the adjusting screw. Loosen the screw and center the indicator.
Tighten the screw and recheck the adjustment.
Your machine will sew on most fabrics without requiring tension
adjustment. If you are using heavier thread or very thick fabric
you may have to increase the tension.
The result you should look for in tension is for the knot to be
formed in the center of the fabric.

9
Hook Timing and Position
With the hook in the race but the race cover not closed, set
the needle position to the far left. Bring the needle to its lowest
position. The tip of the hook should be 2.3 – 2.5mm to the left of
the needle.
If it is not, you will have to adjust the hook position before you
can check the timing.
Loosen the adjusting screw ½ turn only and move the hook
into position. Make sure not to force the shaft the screw is on or
the machine will bind. Tighten the screw and recheck the
position.

10
Hook Timing and Position Continued
Set your machine to far right needle position. From the
lowest position bring the needle up until the hook and needle
meet. The tip of the hook should be just above the eye of the
needle.
In most cases the hook timing on your machine should be fine. If
not adjust the timing.
Locate and loosen the two stroke eccentric screws. Be very
careful not to loosen them too much and do not let the eccentric
drop down. Move the hook to the position shown. Tighten the
screws and recheck the timing.

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