Today on Leah's blog she suggested some great tips to remedy tention problems. Last week, I was in a stand off with my maching, trying to figure out why I was getting the eyelashes and skipped stiches. I tried ALL of these suggestions and then some. I have a vintage 1961 Singer 500 Slant-O-Matic. I wish a had a new fancy schmancy machine, But I do love my singer 500 and will never get rid of it. Determined to not let bad stiches beat me, I got on the internet. I found this great sit on vintage machines TNT Repairhttp http://www.tandtrepair.com/index.html which gives lots of tips.
I learned, that on my particular machine, there is a problem with skipped stitches. I actually talked to a dealer about this a couple of months ago who told me if my machine was skipping stiches, he could put a kit on it to eliminate that. I guess it didn't sink in because I rarely had that problem. Now that I am sewing like a maniac, I see the problem is bigger than I thought. This kit to solve the issue came out in 1975! Also, The TNT Repair site suggests 2 other things.
One, use plastic bobbins. I never had because I had it in my head(and I don't know why) That I had to use metal. The machine is all metal so why not keep the bobbin metal? Here is why. The top thread catches on the ring that holds the bobbin together. Makes sense. There is a visible seam with a visible gap right there. So I switched!
Two, there is an improved threading suggestion that bypasses the 2nd and 3rd thread guides for my particular machine. The reasons are listed on the TNT website.
I still need to get my machine serviced and GET THAT DANG KIT PUT ON! But here is what I am saying in a nutshell. If you have tried all of the obvious. Research your machine. There may be an issue. More importantly, there may be a SOLUTION!!! Good luck!