Not vintage, but still need input - not timing, I think?
09-05-2013, 11:38 AM
#1
Super Member
Thread Starter
Join Date: Jul 2012
Location: Not Here
Posts: 3,817
Not vintage, but still need input - not timing, I think?
Yesterday, I ran into a stumper. A Bernette (for Bernina) 50. Yeah, a plastic fantastic.
When I got it on my bench, the hand wheel couldn't turn in a full revolution, and if the needlebar could have gone all the way down, it would have hit the hook. I disassembled, and found several things:
I've been focused on timing the hook because it was obviously wrong, but I'm starting to think this is bigger than that.
I would appreciate any and all suggestions as to how to resolve this. I feel like I'm so close, but getting so frustrated..
When I got it on my bench, the hand wheel couldn't turn in a full revolution, and if the needlebar could have gone all the way down, it would have hit the hook. I disassembled, and found several things:
- The hook shaft and the timing gear were twisted - The set screw was still in, but it was no longer set against the flat part of the hook shaft. The nylon cogged "track" or the hook gear had "jumped" and this was what was stopping the handwheel from turning. The gear was spun so that a flat part of the gear was trying to mesh with teeth. Indicating she hit something pretty hard. (The pic is post timing adjustment, but pre-set screw adjustment)
[ATTACH=CONFIG]434292[/ATTACH]
No problem, right? "Easy fix"? Uh.
I timed it as close as I could. Honestly, this machine makes "horse shoes and hand grenades" look like precision instruments!
Moving the gear one tooth turns the hook about 3/8"!
I could either time it so that the timing was behind enough that I though it might skip stitches on the right hand side stitches, or so that the needle drags on the hook. I opted for the skipping stitches side of things, for obvious reasons.
I timed it as close as I could. Honestly, this machine makes "horse shoes and hand grenades" look like precision instruments!
Moving the gear one tooth turns the hook about 3/8"!
I could either time it so that the timing was behind enough that I though it might skip stitches on the right hand side stitches, or so that the needle drags on the hook. I opted for the skipping stitches side of things, for obvious reasons.
- Now that it's timed, it picks up the needle thread every time, regardless of the needle position while I test manually (turn the hand wheel by hand, and have fabric under the presser foot)
What it doesn't do is let go of the needle thread. It seems like one of two things are happening:
It just hangs onto it and then it rides back around to pick up another needle thread, and we make a nest.
Looking at the hook, compared to a White ZZ machine here (also an oscillating shuttle), it seems like the hook turns further to the left, and further to the right than the White as well, and I can't help but wonder if this has something to do with its unwillingness to let go of the thread. In my mind, this is still a timing issue, but how can it pick the thread up correctly, but not let it go?
Looking at the hook, compared to a White ZZ machine here (also an oscillating shuttle), it seems like the hook turns further to the left, and further to the right than the White as well, and I can't help but wonder if this has something to do with its unwillingness to let go of the thread. In my mind, this is still a timing issue, but how can it pick the thread up correctly, but not let it go?
I know what the first reaction is: Upper tension too loose.
That's not it in this case. Tension at 9 or tension at 4, the behavior is the same. The machine is threaded correctly, and the thread fully into the tension disks, which are clean. I'm using a Schmetz 15x1 90/14 universal needle which interestingly is slightly longer than the unbranded needle she had in the machine by about 1/16". The manu al calls for HAx130 needles, which as best I can tell is interchangeable with the 15x1. The thread is Gutermann Sew All Polyester, which is about a 50 wt thread.
That's not it in this case. Tension at 9 or tension at 4, the behavior is the same. The machine is threaded correctly, and the thread fully into the tension disks, which are clean. I'm using a Schmetz 15x1 90/14 universal needle which interestingly is slightly longer than the unbranded needle she had in the machine by about 1/16". The manu al calls for HAx130 needles, which as best I can tell is interchangeable with the 15x1. The thread is Gutermann Sew All Polyester, which is about a 50 wt thread.
- The hook seems to turn more than the White ZZ machine (also an oscillating hook) I have here, though their hooks are interchangable. It seems to rotate further left than the White, and it has a greater degree of rotation. Which seems odd and extraneous...
- The other thing I've noticed is that the take up lever is almost 1.5" from it's highest point when the needle is at its highest point. The take up lever hits its highest point when the needle is well into its downswing. It's the only machine like this in the house. Yes, I spun at least 8 of the machines last night to test this theory.
I've been focused on timing the hook because it was obviously wrong, but I'm starting to think this is bigger than that.
I would appreciate any and all suggestions as to how to resolve this. I feel like I'm so close, but getting so frustrated..
Last edited by ArchaicArcane; 09-05-2013 at 11:42 AM.
09-05-2013, 08:07 PM
#3
Super Member
Thread Starter
Join Date: Jul 2012
Location: Not Here
Posts: 3,817
I took another crack at it tonight. I can't see anything tweaked on it. It's as straight as a slightly floppy piece of nylon can be expected to be. 
It can't be in another position as best I can tell. The nylon piece is screwed onto a flat "bar" that goes all the way to the top of the machine and there's no room for adjustment at the screw or any obvious places further up the chain. The other end is held in place by a terrible setup using pieces of flat metal bent into weird shapes and screwed to the frame.
I set the timing, and I reassembled, again, tested by hand - it caught the thread, but didn't let it go again, and as soon as I ran it, it jumped out of time. It won't pick up the bobbin thread anymore, and I can feel that the gear is sitting in the wrong position (handle hard to turn in one spot, but still turns so not as far off as when she brought it to me)
I think it's the weird jerry-rigged side of the nylon gear that's letting it jump time. Typically it jumps one tooth.
I have a sneaking suspicion either there's a piece missing from that nylon part on the jerry-rigged side (nothing dropped out, and it -looks- smooth, but I suppose it's possible for a piece to have broken off and gone through my sewing room's black hole into someone else's sewing room?) or something elsewhere is bent or otherwise ruined.
After my 6th time reassembling and timing, etc, I'm wondering if it -IS- possible to do so much damage that a machine can't hold time anymore. I never bought into that "timing mechanism is worn out", "won't hold a time", etc, but I'm starting to wonder. This isn't my first visit to the Timing rodeo... I would just think it would show something if there was so much damage.
Additionally, without touching anything, the take up lever seems less "off" today. I think this machine just wants to be put to rest. I'd sure rather that wasn't the case though. I'm still open to ideas, I can strip this machine down to it's bare frame within about 5 minutes now. *sigh*
It can't be in another position as best I can tell. The nylon piece is screwed onto a flat "bar" that goes all the way to the top of the machine and there's no room for adjustment at the screw or any obvious places further up the chain. The other end is held in place by a terrible setup using pieces of flat metal bent into weird shapes and screwed to the frame. I set the timing, and I reassembled, again, tested by hand - it caught the thread, but didn't let it go again, and as soon as I ran it, it jumped out of time. It won't pick up the bobbin thread anymore, and I can feel that the gear is sitting in the wrong position (handle hard to turn in one spot, but still turns so not as far off as when she brought it to me)
I think it's the weird jerry-rigged side of the nylon gear that's letting it jump time. Typically it jumps one tooth.
I have a sneaking suspicion either there's a piece missing from that nylon part on the jerry-rigged side (nothing dropped out, and it -looks- smooth, but I suppose it's possible for a piece to have broken off and gone through my sewing room's black hole into someone else's sewing room?) or something elsewhere is bent or otherwise ruined.
After my 6th time reassembling and timing, etc, I'm wondering if it -IS- possible to do so much damage that a machine can't hold time anymore. I never bought into that "timing mechanism is worn out", "won't hold a time", etc, but I'm starting to wonder. This isn't my first visit to the Timing rodeo... I would just think it would show something if there was so much damage.
Additionally, without touching anything, the take up lever seems less "off" today. I think this machine just wants to be put to rest. I'd sure rather that wasn't the case though. I'm still open to ideas, I can strip this machine down to it's bare frame within about 5 minutes now. *sigh*
Last edited by ArchaicArcane; 09-05-2013 at 08:12 PM.
09-06-2013, 06:17 AM
#5
Super Member
Join Date: Jan 2010
Location: Outer Space
Posts: 9,319
Bernettes are not highly regarded for quality. I worked on a cheapie WalMart Brother that had a very similar nylon bar mechanism. It similarly wouldn't stay on track. I do think there's something amiss with it. Like you said, a piece missing, broken or ? The Brother I worked on eventually got chucked. There ARE machines that simply can't be repaired and are disposable. This is why they're sold and made so cheaply. This is one of the main problems with these kinds of machines. The other is bent needle bars. Typically, in well made machines the needle will break if there's a major snag or problem. With these machines, the needle bar metal is weaker than the metal in the needle and the bar will actually bend rather than the needle breaking!
09-06-2013, 10:41 AM
#6
Super Member
Thread Starter
Join Date: Jul 2012
Location: Not Here
Posts: 3,817
Originally Posted by Caroline S
If I ever find a Bernette, I will pass. Sometimes one just needs to end the repair frustration and chalk it up to a learning experience.
Originally Posted by Candace
Bernettes are not highly regarded for quality. I worked on a cheapie WalMart Brother that had a very similar nylon bar mechanism. It similarly wouldn't stay on track. I do think there's something amiss with it. Like you said, a piece missing, broken or ? The Brother I worked on eventually got chucked. There ARE machines that simply can't be repaired and are disposable. This is why they're sold and made so cheaply. This is one of the main problems with these kinds of machines. The other is bent needle bars. Typically, in well made machines the needle will break if there's a major snag or problem. With these machines, the needle bar metal is weaker than the metal in the needle and the bar will actually bend rather than the needle breaking!
I checked the needlebar pretty carefully for this reason. I have heard of needlebars bending, but haven't personally come across one. This needlebar looked pretty good against a straight ruler at several angles, but I wasn't about to disassemble that much too.
09-06-2013, 11:46 AM
#7
Super Member
Join Date: Feb 2012
Posts: 8,091
Tammi,
This may not be of any help, but your thread wrapping around the bobbin carrier is a problem I had with one of my 99K, Rusty.
The machine had tension problems big time. I worked and worked and worked on it, but nothing I could see was the cause of the thread and tension problems. There were rusted parts in the top tension and the bobbin area and those were each replaced in turn. But as I tried to sew with the machine the thread would loop underneath badly then wrap around the bobbin carrier and jam up the machine. Nothing I replaced fixed the problem.
Then I sat Rusty beside another machine that worked properly and the problem slapped me in the face.
The thread take up lever was in wrong and never made the full up stroke. This left the top tension loose. One of the parts I had replaced was the TU lever assembly. It came to me broken. I didn't get it in right.
I pulled the face plates from both machines, set them so the good sewing machine's lever was full up, then put the Rusty's needle bar and hook in the same position as the first machine. At that point the take up lever was way off.
I took the TU lever and it's parts out, then put them back in so they matched the other machine. The problem was solved.
This may not be the cause of the Bernette's problems, but since things were twisted around, I thought I'd mention it.
Joe
This may not be of any help, but your thread wrapping around the bobbin carrier is a problem I had with one of my 99K, Rusty.
The machine had tension problems big time. I worked and worked and worked on it, but nothing I could see was the cause of the thread and tension problems. There were rusted parts in the top tension and the bobbin area and those were each replaced in turn. But as I tried to sew with the machine the thread would loop underneath badly then wrap around the bobbin carrier and jam up the machine. Nothing I replaced fixed the problem.
Then I sat Rusty beside another machine that worked properly and the problem slapped me in the face.
The thread take up lever was in wrong and never made the full up stroke. This left the top tension loose. One of the parts I had replaced was the TU lever assembly. It came to me broken. I didn't get it in right.
I pulled the face plates from both machines, set them so the good sewing machine's lever was full up, then put the Rusty's needle bar and hook in the same position as the first machine. At that point the take up lever was way off.
I took the TU lever and it's parts out, then put them back in so they matched the other machine. The problem was solved.
This may not be the cause of the Bernette's problems, but since things were twisted around, I thought I'd mention it.
Joe
Last edited by J Miller; 09-06-2013 at 11:48 AM.
09-06-2013, 12:23 PM
#8
Super Member
Thread Starter
Join Date: Jul 2012
Location: Not Here
Posts: 3,817
Hey Joe,
Thanks for this. I looked at that TU lever again last night and it didn't seem as bad. I suspect something in there is stripped.
Just to be clear, was Rusty looping first then binding the hook or not letting go of the thread first then causing the nest? I completely understand the looping from too much thread hanging out down there causing problems. I can't figure out why it would choose not to bother coming off the hook. Maybe the thread is too tight? It looks and feels fairly tight around the bobbin case too. That said, there's a "loop" near the TU lever when this all happens. More than I'd suspect there should be.
I've seen this problem once before and for the life of me I can't remember what the solution was.
I'm thinking that Caroline is right, it's time to put an end to this pain. If it won't hold settings, I can't guarantee it will hold together.
Thanks for this. I looked at that TU lever again last night and it didn't seem as bad. I suspect something in there is stripped.
Just to be clear, was Rusty looping first then binding the hook or not letting go of the thread first then causing the nest? I completely understand the looping from too much thread hanging out down there causing problems. I can't figure out why it would choose not to bother coming off the hook. Maybe the thread is too tight? It looks and feels fairly tight around the bobbin case too. That said, there's a "loop" near the TU lever when this all happens. More than I'd suspect there should be.
I've seen this problem once before and for the life of me I can't remember what the solution was.
I'm thinking that Caroline is right, it's time to put an end to this pain. If it won't hold settings, I can't guarantee it will hold together.
09-07-2013, 05:07 PM
#9
Super Member
Join Date: Jul 2011
Location: St. Louis suburbs
Posts: 6,084
I have a Bernette and I don't like it at all. It seemed to me that it was in the shop all the time. Since I had it repaired the last time, it has sat there on the shelf. My repair man had a hard time fixing the darn thing, but he finally found out what was wrong, said it was really difficult. I bought this machine about 2000.
Thread
Thread Starter
Forum
Replies
Last Post
Teeler
Main
13
03-05-2013 10:24 AM
Kookie
For Vintage & Antique Machine Enthusiasts
7
07-25-2012 05:11 PM
solstice3
For Vintage & Antique Machine Enthusiasts
2
01-29-2012 04:42 PM
AngieS
For Vintage & Antique Machine Enthusiasts
0
11-06-2011 02:25 PM
