Hi, These machines are designed for professionals, and you have some great comments from Bill, but here's what I can add:
I will try to tell you here how to thread and operate it.
Machine operation: Turn the machine on, you will notice that it 'surges' up to full power. Without any thread in the machine, press the foot pedal til you feel you can control the speed a bit. Move your right foot forward or backward on the wide presser foot to adjust the speed too. Now turn the machine OFF, and keep pressing on the foot pedal, notice how the machine 'winds down' to stop. This is a safety issue: it won't stop immediately when the power is turned off!!!
To lift presser foot, move your right knee 'out' to the right, and it should push a bar to the right, which will raise the foot. (yes, you can move the foot up by hand too)
Now locate the bobbin area under the needle. Access is through the side, under the table. To see this area better, push the 'head' of the machine back so that the machine 'tips back' and exposes its underside. The area below it is the 'oil reserve'. There should be clean oil in there. Don't procede if it is empty. The exception would be a really ancient machine that does not 'self oil', in which case you need to do that now.
Pop in the bobbin case a few times to get familiar with that process. The bobbin is 'up' when the little half-moon shaped scoop on the bobbin case edge is facing up towards the needle. Any other position of the bobbin case will break the needle.
Bobbin: how to wind it
1--the smaller upper belt on the right side of the machine DOES wind the bobbin (they wind one at the same time they are sewing). If you push a lever in the front away from you, it will 'lock' in place and turn when the machine is on.
This is threaded using CONE thread (never use spools)> Start with a cone in the thread stand, bring the thread STRAIGHT UP to the arm or wire above the cone and pass thread thru the eye or loop. The thread needs to go straight up, so turn the upper arms til they are above the thread cone. Now take the thread down to the BACK tiny loop or eye of the bobbin winder. You will pass the thread thru the TENSION disks first, then the eye, then wrap around the bobbin a few times. Now push the bobbin onto the 'axel' of the bobbin winder. Finally push the front lever of the winder forward so it 'clicks' in place. Run the machine until the thread has wound.
Putting bobbin into bobbin case: You will need to catch the bobbin thread under the bobbin case tension flap. If you don't know what I mean by this, check a sewing book, since the bobbin is used the same way as a home sewing bobbin case.
Now pop in the bobbin case, keeping the half moon cut-out facing up towards needle, hear it 'click' in place.
(NO POWER) Thread the machine. Use same cone thread as bobbin, pull thread from the upper eye or loop down to the machine. It will pass through a tension disk at the top (usually), then around a wire or bar 'guide' before going down to the tension disks. Pass thru the tension disks and catch in the 'springy wire' that is attached to the tension disk, now go up to the big lever that 'yanks' the thread up and down, then take the thread down to the needle. Thread need from LEFT to RIGHT (note: these machines thread almost exactly the same as ancient single needle straight stitch machines pre-zig zag days, so old sewing books from the library may help)
needle: must be specialized for this machine, do not try a home sewing needle. Use a size 14 for your heavy duty project. The long groove of the needle faces the LEFT and the 'ditch' side of the needle faces the RIGHT. You will have to pivot needle into place, then tighten the screw.
(NO POWER) Press the foot peddle forward with your right foot, this will allow you to turn the hand wheel on the right and pull up the bobbin thread. The needle will be very hard to turn without pressing that foot pedal a tiny bit--remember this when you are sewing. Also, turn the hand wheel on the right side of machine TOWARD you to walk stitches or pull up bobbin thread.
OK--that's it.--good luck, Jennifer
p.s. Many dry cleaning businesses have this type of machine. You might take a peek at one there, or even get them to sew it for you!