Wednesday, November 20, 2013
Rocketeer #1 is Finished!
This machine is one I thought was 100%. However, when using it, the light switch was very touchy - I had to turn the light on & off several times before it would stay illuminated. Since I was going to part out Rocketeer #3, I decided to cannibalize the light assembly for #1.
Removing the upper lid, I noticed that the bobbin winder return spring and the bobbin winder latch spring were both not working properly. So much for 100%!
I posted a few days ago how to replace the bobbin winder return spring and I just had to bend the end of the latch spring and reattach it to the latch to remedy those issues.
I should have made a tutorial on how to replace the light assembly, it turned out to be a bit more complicated than I had envisioned but I didn't take any photos so it would not be too informative.
The easy way is to cut the wires just inside the machine housing and splice the new socket to the existing wiring but I elected to do it the hard way and replaced the socket and wiring as a single unit, threading the wire down to the main connector.
When I reassembled the 500, I found that it would zig, but not zag. At full zig zag width, the needle would go full left and come back to center, but not go from center to the right. Slant-needle Singers only have a paltry 4 mm zig zag to begin with and cutting that in half leaves that function essentially useless.
I oiled everything I could get at several times, let it sit, ran it at high speed to work in the oil, but nothing helped. I could manually push the needle to the right, but it would not go there under its own power.
I spent much ofafternoon and most of Veteran's Day fiddling with that one problem. The service manual was no help, but the diagrams did convince me that the cause was either a binding needle bar vibrating bracket or a binding needle bar driving arm.
The needle bar vibrating bracket was the most easily accessed, so I tackled it first. I loosened the collar below the bracket that holds the bracket in place to be sure that the binding was not at this point.
Of course, being the easiest fix, that was not the problem.
The needle bar driving arm is an I-beam connected to the needle bar vibrating bracket one end and a forked end connected to the stitch selector. At the end of the lower fork is a thing called a "ball pivot". From what I can tell, it looks like a metal Tootsie Pop with a round globe on one end and a shaft on the other end that hooks to the bottom fork of the needle bar driving arm.
The "ball" of the ball pivot sits in a tunnel in the side of the stitch selector and keeps the driving arm aligned. The ball slides back and forth in the tunnel as the driving arm moves left and right to re-position the needle.
I had oiled the back side of the ball pivot several times but the oil had apparently not penetrated far enough into the tunnel to lubricate the ball and make it slide freely. To get at the front side of the ball, you need to remove the camstack. Once the camstack is out, the tunnel is visible on the left wall of the stitch selector.
I tipped the machine on its nose and filled that tunnel with sewing machine oil and let it sit for an hour. When I next tested the machine, the zig zag was still at 2mm. I put pressure on the needle bar driving arm to encourage it to move the needle to the right and after a minute of running the machine and adding pressure, the zig zag opened up to its full 4mm.
That was aboutlast night and I am glad I didn't have to go to bed with that on my mind.