Timing off set screws came loose on shaft how to reset timing?

Take a close look at the gears on the shafts.
It is possible that one of the locking screws has become loose.
Not knowing which machine it is does not help.
Use the appropriate tool to make sure that they are all tight.
Also check the position of the screws in relation to locating points.
Like do the screws sit on a flat part of a round shaft?
Or is there a c shaped pin that goes through the shaft.
Probably the first one to check is around the motor, is it belt drive?
Belts need adjusting occasionally, if a belt has been loose for a long time replace it and adjust the belt tension.

Hope this helps.

Regards
Geoff

youtube has good videos. Check this link, you will probably be able to see how the part is attached. Brother XL 6562 YouTube

Could be the feed dogs are not advancing the fabric. First check to insure that your stitch length is adjusted correctly. Also insure that the clutch wheel is tightened (little wheel inside the big wheel). If stitch length is set to 1 or 0 (darning setting) this is your problem. If the stitch length is correct then rotate the machine by hand and watch the feed dogs to insure that they are moving in an elliptical pattern and rising above the throat plate. If the feed dogs are not moving then the hex screws securing the connecting rod that connects the feed dog mechanism to the drive shaft may have worked loose. If this is the case the timing will need to be readjusted and the screws tightened.

Bit technical for me but I'd suggest you join the Elna Heirlooms group on Yahoo.com, and then ask there, there are lots of very helpful members who share photos, service manuals and their vast knowlege on these vintage machines.

The top hex screw I think holds the bushing that allows it to slide freely. Keep that loose. If you open the panel where the lightbulb lives and spin the wheel, you will see a small flathead screw come into sight near the top of the rotation, through a small round window in the case. Tightening this screw a bit should keep the needleshaft moving with the wheel. Unfortunately I am still trying to find out how to position it so that it's properly timed.

I have a used unit with the same problem. If you remove the plastic housing piece on the far left you can see how the foot lifter works. Raising the lever raises a collar around the main shaft. There is a screw in that collar which connects the collar with the shaft. If that screw is loose the collar will not raise the shaft. Caution: Tighten the screw very carefully, only enough so that the shaft lifts. I just overtightened and the collar has a crack now.

Oh dear..... Bent looper and needle arm loose... Take this to be repaired before you damage the other looper as well and it costs twice as much. Expect looper to be in range of $65 plus service, as a ballpark. There are many variables with overlocker timing and it is beyond the scope of either this forum or the novice to correct the problem I am afraid.

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).

Timing
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.

If 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,

Tighten the screws you have loosened and try simply cleaning the the machine with a small, dry, clean paint brush. Put one drop of oil on all moving parts you can see and through any oiling holes on the top of the machine. If the machine is computer operated you will need to unplug the power from the machine for a few minutes to give time for the computer to reset itself.
Zelma

OK, this is a general timing procedure. Loosen the screws on the main shaft gear that goes to the hook drive gear and separate the gears. Next put the needle in the left position and bring the needle all the way down by turning the handwheel. As the needle comes up make the point of the hook enter the scarf of the needle (just above the needle eye)and hold it there while you put the gears back togeather and tighten the screws. This should put it close to being in time. To fine tune it you can loosen the needle bar screw (half way up the bar that holds the needle) and adjust theneedle so the hooks point is just above the needle eye. You may have to do this a few times in order to stop it from skipping stitches. Good luck. Rick