Originally Posted by
Mizkaki
Joe,
It's really rare for these old straight stitch machines to go out of hook timing. They usually had a roll pin placed instead of a set screw when the factory set the timing, making it darn near impossible for the timing to go out.
Frequently the needlebar height is the issue. Needlebar height always has to be set before
the hook is timed, so start there. This is the way I check. Turn the machine’s handwheel in the normal direction until the point of the needle reaches “dead bottom center”. DBC is where the needle is at it’s lowest point. Starting there turn the handwheel until the needle has risen exactly .093 inches. The point of the needle should now be directly behind the needle in the middle of the scarf (dip in the needle just above the eye). If not, where is the point? If the needle has risen .093” and the hook point is not behind the needle then the timing may be off. If it is behind the needle, but not in the scarf then the needlebar height is off.
Always start with a new needle and make sure it is not a stretch needle.
You said that the thread jams. Which thread, needle or bobbin? Check both tensions. Make sure the presserbar is down (easy to forget).
Cathy
A good percentage of the vintage straight stitch machines I have had timing issues. One was completely out of time and the others could sew a straight stitch, but the moment I FMQ'd had skipped stitches which is a sign of the timing not being perfect. All of the 301's I've purchased have needed timing adjustment and were too far away from the hook. We need to remember that factory settings after 50 years have probably been played with by service techs and or those playing with the machines that don't necessarily know what they're doing. My 301's now FMQ beautifully, but it took me some time to figure out what the problem was and correct it. I even had one 301 that was missing a hook screw that made it go out of time every occasion I used it.