The knives were removed during dis-assembly for the safety benefit of the timing of the loopers. Everything went fine with three threads and the needle; then four threads with two needles. She was satisfied with near-perfect stitch patterns. But when the knives were re-installed, everything went haywire! See attached picture. Do you have any advice at this point?
Also, she needs to know what lubricant to use with a metal gear meshing with a nylon looper gear in the gearbox. She removed the old grease from the gears and applied the Singer gear lubricant temporarily. By comparison, it seems to be too light a lubricant to replace the heavier grease.
For lubrication, just use a fine machine oil or sewing machine oil. I found it better to oil with every service. The grease always seem to get hard over time.
ReplyDeleteYour blades don't seem to be the problem.
Please check the following.
Make sure the pin on your needle plate that divides the needles are there and that it is without any sharp edges that can make the cotton bunch up. I don't think it is the problem
Get some Schmets needles size 90.
Make sure the looper's point is still nice and sharp and does not have a blunt point or a sharp edge where the cotton can hook. The point must be very smooth and polished.
When the lower looper passes behind the needles, it must almost touch. You have to follow the setting of the timing carefully. I still get it wrong sometimes.
Sometime the upper looper can touch the needles too much and push it back. This is only a problem if your needles don't straiten before it hits the material. It will work fine on stretch but not on cotton that pushes the needles even skewer.
I think the main problem lies with your lower looper timing.
The top blade should overlap the bottom blade with .5-1mm.
Hope that helps