Anyone who has a Singer 500 or 503, aka "Rocketeer" knows of the unique spool pin arrangement. There are no spool pins on the outside of the machine, you lift the top lid and two spool pins pop up ready for thread.
I hate this arrangement, I don't like sewing with the lid up and the pins are often slanted so the thread doesn't unwind properly. The alternative is to plug a plastic spool pin into the hole in the lid.
When sewing on a Rocketeer, I leave the lid closed and use a thread stand. Actually, I use a thread stand most of the time because I use the large cones of thread instead of the little spools you buy at the fabric store.
We went to Lancaster, Pennsylvania a year ago and one of the fabric shops up there had a large bin of cones for $4 each. I bought a half dozen and, when we returned this year, and I bought seven more. I really like not running out of thread in the middle of a project. I just wish they had more neutral and light colors in the bin.
I digress - back to the spool pins. The Rocketeer spool pins are thin plastic with a couple of little pieces sticking out acting as pivot points. Needless to say, they break off often, so I picked up some to stock in the Etsy Old Sewing Machines Shop.
Replacing the pins is not difficult, you remove the upper lid and turn it over; release the spring from the broken pin,
Now, if the spring is missing, stretched out, or broken, you have another problem. While the spool pins retail for 80 cents apiece, the springs retail for $4.80 each! This got my creative genes stirring to find a cheaper option. I got out the piano wire left over from my bobbin winder spring episode and wound a spring around a nail.
Unfortunately, the piano wire is considerably thicker than the original spring wire and the spring didn't have enough "spring". Then, I thought that the spring looks similar to the one in a retractable ballpoint pen. I disassembled a cheap pen, bent the ends of the spring and installed it.
Works well for now but I'm not sure if it will get stretched out or how long it will last. I will continue to look for a substitute or order some lighter spring wire.
The next problem is the spool felts that help keep the thread unwinding smoothly and prevent the spool from rattling as you sew. The standard spool pin felts don't work because you need a slot for the pin to fold down into.
Cutting a slot in a standard spool pin isn't the best option because the spool felt can rotate and the slot won't be where it needs to be when you lower the lid. My parts supplier doesn't carry the 500 spool pin felts, what I do is buy a sheet of adhesive felt from the craft store, cut out a circle, punch a hole in the center,
cut a slot for the pin to fold into
and adhere the homemade felt to the lid. Not original looking, but it does the job.
Ed's Vintage Sewing Machine Shop