PARACHUTE RIGGER HANDBOOK
 

OPERATION

Before you first sit down in front of the machine, check to see that the power cord is plugged in.

Many of the modern machines are self-lubricating and have an oil reservoir in a pan below the head. Make sure there is oil of the correct type and to the correct level.

Next, remove the bobbin case and bobbin from the machine and the upper thread from the needle. This allows you to check to see if the bobbin case is clear and free in operation.

Without turning the power on, depress the treadle lightly to release the clutch. Turn the balance wheel or drive pulley TOWARD you and cycle the needle up and down several times to see if the machine turns freely. Listen for any sounds that seem abnormal and notice any feeling of tightness or binding of the machine.

If everything seems normal, re-thread the needle. Take a full bobbin, place it in the bobbin case [Figure 6-74], and install it in the shuttle of the machine [Figure 6-75].

Cycle the needle down and pick up the bobbin thread. A correctly threaded and timed machine will pick up the bobbin thread on the first cycle.

INSTALLING THE NEEDLE AND THREADING THE MACHINE

All single needle type machines have the needle positioned in the needle bar with the long thread groove facing to the left. Make sure that the needle is installed all the way up to the stop in the needle groove of the needle bar. Check that the long thread groove faces left [Figure 6-76] and that the needle clamp screw is tight.

Take a cone of thread and place it on the thread stand. Route the thread upward through the guide at the top of the stand and then to the pre-tension thread guide on top of the arm of the machine. Thread the machine according to figure 6-77. Most modern machines use a similar method of threading. However, there may be additional thread guides of different shapes to route the thread through. This is why the rigger should have a copy of the operatorís manual for proper threading of each machine.

Once the machine is threaded correctly, take a sample of material suitable for the type of machine, thread, and needle. Form several layers and place it under the presser foot. Lower the presser foot while holding the upper and lower threads securely to the rear of the presser foot. Turn the balance wheel again and run a few stitches by hand to see if the machine sews properly. If everything works as expected, turn the power on and begin sewing. If you are unfamiliar with this particular machine, begin slowly until you get the feel of the clutch and speed of the machine.

If the machine does not sew correctly, consult the troubleshooting guide [Figure 6-78] to determine what the problem is and how to remedy it.

 

 
 
 
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