Can a worn case/hook prevent adjustment of case opener lever.

[beefy]

52 minutes ago, friquant said:

Looking  forward to this!

will have to make a before and after video.

[beefy]

OK here's two videos. One is me moving the pulley very slowly so the action of the case opener on the case/tab can be seen, and how the case opener itself is still in contact with the case when the thread tries to pass through at the end. That's where the problem lies. As mentioned earlier, if I back off the case opener slightly to allow the thread to get through, the case tab is not rotated anti-clockwise enough to let the thread past the front side of the tab.

The 2nd video is to show how much "rocking" there is in the case as it rotates. It's floppy as hell.

[AlZilla]

I'm glad we're moving forward on this one. When I get home tonight, if there's not some resolution on this, I'll go up and rotate through my similar machine.

[Wizcrafts]

Either the latch opener arm is bent down too far or the hook is sitting too high up.

[friquant]

Is this the before or the after?

What size thread?

Looks to me like the latch is opening further than you need for this thread size. Adjust it to open a little less, and you'll get easier clearance on the second side.

Also Wiz' comment: "Either the latch opener arm is bent down too far or the hook is sitting too high up." If the hook were down a bit lower it would be easier to clear the latch. Perhaps too many washers under the hook?

Also looks to me like the timing is too advanced. If you retard the timing a little, maybe the hook will be out of the way when the thread is trying to go through the second half of the gate, giving the latch a little more time to close.

[Wizcrafts]

4 hours ago, friquant said:

If the hook were down a bit lower it would be easier to clear the latch. Perhaps too many washers under the hook?

If there really are washers under the hook, removing them will advance the hook timing.

[AlZilla]

27 minutes ago, Wizcrafts said:

If there really are washers under the hook, removing them will advance the hook timing.

Because of the helical cut drive gear? 

[beefy]

11 hours ago, Wizcrafts said:

Either the latch opener arm is bent down too far or the hook is sitting too high up.

You've lost me on that one Wizcrafts. The case opener arm is at the same height as the triangular outcrop on the case on which it pulls against.

[beefy]

11 hours ago, friquant said:

Is this the before or the after?

What size thread?

Looks to me like the latch is opening further than you need for this thread size. Adjust it to open a little less, and you'll get easier clearance on the second side.

Also Wiz' comment: "Either the latch opener arm is bent down too far or the hook is sitting too high up." If the hook were down a bit lower it would be easier to clear the latch. Perhaps too many washers under the hook?

Also looks to me like the timing is too advanced. If you retard the timing a little, maybe the hook will be out of the way when the thread is trying to go through the second half of the gate, giving the latch a little more time to close.

This is the before Friquant. It's the old wobbly case.
Won't get to install the new hook/case until maybe this weekend.

Thread is Coats Dabond V138 for which the machine is rated.

I've tried adjusting the case opener arm both ways in tiny increments. I cannot find a happy medium that pulls the case anti-clockwise enough to open the gap enough on the rear/far side of the case tab, yet opens the gap between the case opener arm and the triangular outcrop on the case when the thread goes around the other side of the hook. I can get one or the other but not both. This is why I'm suspecting the slop in the case and how it leans towards the needle plate, to be a potential cause of the problem.

Regarding the latch. I'm kind of guessing at the moment at what part is referred to as the latch, so I'd better not go further before I make sure I'm on the same page as everyone.
The curved arm that's operated by the eccentric under the hook, I've been calling that the case opener arm.
The case opener arm pulls against the triangular outcrop on the case to rotate it anti-clockwise. This is where the biggest problem is as the gap between these two comes too late and the thread gets stuck there a little.
Then there's the tab of the case that sits in the slot of the needle plate.
So is one of those being referred to as the latch.

 

Edited 7 hours ago by beefy

[friquant]

 

22 minutes ago, beefy said:

So is one of those being referred to as the latch.

In my mind, the latch (or gate) (or gap) is the thing the thread attempts to cross.

The latch is comprised of these two pieces together: the bottom of the throat plate which has a wide gap in it, and the piece of the bobbin case that exists in that wide gap, sometimes at the front of the gap and sometimes at the back of the gap.

23 minutes ago, beefy said:

This is the before Friquant. It's the old wobbly case.

Okay. I'll bet you'd rather wait for the new one than try all the things we suggested 😉