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

[beefy]

1 hour ago, friquant said:

 

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.

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

Fantastic, great to be on the same page as everyone.

Yes, I agree. The new hook arrived a couple of days ago but I won't get a chance to swap it out until hopefully this weekend.

I will create video #2 (the "after" video) when it's done, and hopefully I have a flawlessly working machine. 

The best part of all this is what I'm learning from you guys, so thanks very much everyone for your kind help.

[AlZilla]

 

 

I'm not sure video of my 111w is going to be very instructive. It looks a lot like yours, only with more motion. 

 

[friquant]

4 hours ago, AlZilla said:

It looks a lot like yours, only with more motion. 

Wow, lots of travel! And seems to achieve it furthest reach earlier in the rotation of the hook than the OP machine

[beefy]

5 hours ago, AlZilla said:

 

I'm not sure video of my 111w is going to be very instructive. It looks a lot like yours, only with more motion. 

 

Thanks AIZilla.

Looks like your case opener arm is not adjusted correctly, as it does not even contact the triangular outcrop on the case to pull the case anti-clockwise and open the latch on the rear/far side. It appears the thread itself is simply pulling on the tab of the case and thus forcefully pulling it anti-clockwise then the thread goes through the latch.

[AlZilla]

2 hours ago, friquant said:

Wow, lots of travel! And seems to achieve it furthest reach earlier in the rotation of the hook than the OP machine

Funny, I didn't really look at it other than the height of the hook and opener. It's been running a couple of years now. Maybe mine needs adjusting, too.

[beefy]

8 hours ago, AlZilla said:

Funny, I didn't really look at it other than the height of the hook and opener. It's been running a couple of years now. Maybe mine needs adjusting, too.

I remember one guy's Youtube video, where he reckoned the case opening mechanism is only important for thinner thread. I think he said the thicker (stronger) thread will just pull the latch open.

Whether what he said is correct or not I have no idea.

[AlZilla]

4 hours ago, beefy said:

I remember one guy's Youtube video, where he reckoned the case opening mechanism is only important for thinner thread. I think he said the thicker (stronger) thread will just pull the latch open.

Whether what he said is correct or not I have no idea.

Doesn't sound right to me. It really doesn't take much to disturb the thread path. If this bloody weather ever breaks, I'll go up and check it out. The last couple mornings the car said 20 below (F). The craft area isn't really cozy right now.

[friquant]

10 hours ago, beefy said:

I remember one guy's Youtube video, where he reckoned the case opening mechanism is only important for thinner thread. I think he said the thicker (stronger) thread will just pull the latch open.

Whether what he said is correct or not I have no idea.

(At least some) Machines with a horizontal hook axis and a rotary hook (such as the Juki DDL-8700) don't have a latch opener. Yet the latch opens before the thread gets to it. I suspect maybe the thread dragging across/around the bobbin case is doing it, but I haven't studied it enough to be sure. Maybe that's why the hook moves the opposite way on those machines versus a lot of the machines I see with a horizontal hook axis + oscillating hook like the Singer 31-15.

[beefy]

15 hours ago, AlZilla said:

Doesn't sound right to me. It really doesn't take much to disturb the thread path. If this bloody weather ever breaks, I'll go up and check it out. The last couple mornings the car said 20 below (F). The craft area isn't really cozy right now.

Yeah, I'm trying to get at my sewing machines but a few other tasks are ahead. Apart from that, excess heat is my problem here in Australia LOL.

Would a 5Kw Chinese diesel heater be big enough to heat your craft area. I love those little toys. Want to put one in my boat when I make the fabric cabin so I can go out in freezing winter and be toasty warm.

[beefy]

Finally got around to the hook swap thanks to pulling my lower back and not being able to do higher priority work LOL.

The new hook (cheap Chinese off Ebay) was not identical to the worn out hook in the machine. Problem is I don't know if the original worn out hook from the machine is OEM or not because it does not have any Singer markings anywhere. The case had Singer markings but that could be an original case in an aftermarket hook, no idea.
The V-slot in the shaft of the new Chinese hook was in a different position, see this thread:

Something else I checked was the position of the eccentrics on both hooks, relative to the position of the hook point. As can be seen in the attached photo the new hook (left in the photo) had the highest point of the eccentric more advanced than the old hook. The blue marking on the hooks indicates where the eccentric sticks out the most. This was checked with a dial indicator.

This advanced position of the eccentric on the new hook seems to have been beneficial to the case opener arm operation, and the case opener arm now releases earlier, and I don't get the problem I explained earlier, where the thread could not get past the case opener arm and the triangular outcrop of the case.

Also attached a video of the the case opener operation and the material passing the latch.
A point of note is I've also ground a chamfer on the front / operator side of the needle plate slot, as this was acting as a pinch point with the new hook.

So far the operation seems good now, but I have to try it powered to be fully sure. It just on the bench at the moment while I'm doing various jobs in my workshop.

 

Edited February 6 by beefy