Sewing Machine Timing

[Charlie]

Hi All,

Looking for help with a new to me sewing machine. It is a sailrite sailmaker. Worked fine for about half an hour then . I broke a needle and it won't pick up stitches now. I have tried timing it but am having a problem. When I set the zig zag to the extreme left and set the hook and the needle so they are almost touching the thread picks up fine. But when set to extreme right the needle is 1/6" or more away from the hook and the thread slides past the hook. Then I set the machine to the extreme right and set the hook and needle correctly. After that when the machine is in the extreme left position the needle rubs against the hook and while the hook pushes the needle out of the way and tears the thread the needle does not break.

Does anyone have any suggestions?

I suspect something is bent but don't know which part.

[a64pilot]

I don't know squat about a sewing machine despite having just buying one myself.
I'd call Sailrite, they supposedly have good customer service

[Sea Dreaming]

You might need to loosen the tension when you put in a new needle. Tighten the tension slowly to the amount you need. You might have to run a few test scraps to get it right. Especially true if using zigzag. Also, make sure your needle is position correctly in the arm. The eye must be facing you exactly. Put a piece of card behind the eye to make it easier to see and position.

Also, call sailrite. They really can help you best.

[Charlie]

Thnx for the ideas will call sailrite now

[neworleansrich]

The timing adjustment is not done on the gears but rather on the vertical shaft that goes up and down with the needle. There is a set screw. Sometimes if the screw is a bit loose the shaft moves as it punches through heavy fabric.

[UNCIVILIZED]

I've pulled a few machines apart which essentially had cams for timing the various bits. Though to me they looked more complicated than an engine's valve train. At least compared to the old school valves setups. So it can be easy to make things worse if you just start guessing. Thus a good analytical process is in order, & having help/guidance doesn't help either.

When I mentioned having worked on a few machines to a sail loft, their ears really, really perked up. Which surprised me, as they're one of the premier small lofts on the planet. So I'd have figured them to have had tuning their machines well in hand. That says a lot about the machines' complexity to most folks, even experts it seems.

[Charlie]

Thanks for the advice. It has taken me awhile to understand the mechanics of a sewing machine. The three variables are 1) the needle height, 2) the hook needle timing, and 3) the hook needle clearance. If the height is wrong e.g. the eye is above the bobbin thread then the hook will never create a stitch. If the hook needle timing is off if may create a stitch on only one side. If the hook needle clearance is too great then the thread may never be picked up by the hook and create no stitch at all. If it is too close then the needle may be deflected and/or the thread frayed and broken. I had a combination of all of these problems. the prvious owner had tuned the sewing machine but had not torqued the screws tight enough so when the machine hit a hard spot everything was thrown off. I am closer to getting this figured out. Now the right hand stitch is missing. A small clockwise adjustment should help me to accomplish the correct timing. I think?

[senormechanico]

Originally Posted by neworleansrich

The timing adjustment is not done on the gears but rather on the vertical shaft that goes up and down with the needle. There is a set screw. Sometimes if the screw is a bit loose the shaft moves as it punches through heavy fabric.

That screw is for needle CENTERING not timing.
It will affect timing a bit, but should not be used for timing.s
With the machine set to straight stitch, adjust that screw in the pic (loosen the nut first) to center the needle.
Properly adjusted, the needle should be in the exact middle, then with full stitch width, the needle should equally just clear each side of the needle plate slot.

I suspect the needlebar has been slightly jammed upward.

Steve

Sewing Machine Greenbank, WA - S & J Sewing Machine Services