Singer 7-33

[freeflaw]

I don't know how to time my machine. Had a needle strike that seemed to have messed with the timing. I can't use a generic video or info to time this machine as the bobbin race operates differently from machines that I have yet dealt with. The bobbin race does not rotate once around. After picking up the thread, the bobbin race does a little more than a 1/2 turn into on direction, drops the thread and turns back the 1/2 turn (as opposed to rotating once around to complete a cycle). The manual doesn't specify anything. The guy that I bought the machine from doesn't know either. Maybe you guys can help.

[Constabulary]

As far as I know the Singer 7-33 can be timed by just loosening the screws at the needle bar and and set the needle bar at the point where the hook hits the small gap of the needle in the upwards movement of the needle bar. This is a very basic description but this works with my Adler 4 + 104 and as far as I know at the front end they are technically identical with the Singer 7. You probably just have to make just a small downwards adjustment of 1 or 2 millimeters. Maybe you need a few tries to find the best position where the hook catches the thread perfectly.

See picture - don´t forget to tighten the screws again

Edited October 9, 2013 by Constabulary

[Constabulary]

BTW - I would make a small mark above the clamp with a permanent marker or scratch one with a needle. So you know the old position in case something goes wrong.

[Gregg From Keystone Sewing]

Timing on a 7-33 is 5/32" needle rise from hook point to center needle with the needle bar starting at the bottom most point. The machine's timing, from the factory, and from anybody for that matter, is pinned with taper pins. Going from the handwheel, the top shaft has a U in it, that drives the main connecting rod, that drives the large forked crank with slide block lower in the machine arm. The slide block is connected to the crank that is pinned onto the hook driving shaft. On the opposite side of the hook driving shaft is the hook driver, that is also pinned onto the hook driving shaft. Both crank and driver have a set screw, but they are really only for setting the parts, the pins are doing the work.

So...I would check that one of the pins are not broken. You can put a mark from the driver and crank onto the shaft, and see if they move independently, this would show if that one of the pins are broken.

Other than that, the needle bar height is what you have to adjust here.

Edited October 9, 2013 by Gregg From Keystone Sewing