I'm about to kill my new Bernina activa 230

On Mon, 24 Nov 2008 11:32:32 -0500, Martha wrote:
It simply will not hold its tension.

One good seam, and the next one has the bottom thread all tangled and
loose.

I'm assuming you're using regular "dressmaker weight" sewing thread and
at least a size 10/70 needle, so you're not dealing with thread
wedging into the long groove of the needle -- this can look like a bad
upper tension. And that you've tried another needle.

Cruddlies between the tension disks? Have you tried cleaning those?
Dampen a fold of well-washed muslin with rubbing alcohol or unflavored
vodka. Raise the presser foot to open the tension disks and put the damp
muslin between. Lower the presser foot and pull the fabric through. Repeat.
Finish up with dry, much washed muslin and try threading up again.

The other two mechanical causes I've seen of intermittent upper tension
problems (on other machines, not yours) have been bad tension spring
and a catch in the release that causes the disk to close when you drop
the presser foot.

Do you always raise the presser foot at the end of the seam, and then lower
it to start a new seam, and then the machine misbehaves from the start?
Or does the problem ever start in the middle of a long seam?

The first case would suggest spring or presser foot connection problems,
while the second sounds more like upper tension cruddlies shifting around
and making mischief.

Oh, and is your presser foot properly attached? I did see one case with an
old slant needle machine where the foot wasn't on quite right, but it jammed
enough to allow decent fabric transport. But it wasn't letting the bar holding
the presser foot drop enough to engage the upper tension. Remounting the
foot cured the problem. That was one of those headdesk moments....

Kay, amateur sewing machine mender

Oh , I like that way to clean the discs better than the folded up dollar
bill !!
Thanks, Mary in VT




"Kay Lancaster" wrote in message
...
On Mon, 24 Nov 2008 11:32:32 -0500, Martha wrote:
It simply will not hold its tension.

One good seam, and the next one has the bottom thread all tangled and
loose.

I'm assuming you're using regular "dressmaker weight" sewing thread and
at least a size 10/70 needle, so you're not dealing with thread
wedging into the long groove of the needle -- this can look like a bad
upper tension. And that you've tried another needle.

Cruddlies between the tension disks? Have you tried cleaning those?
Dampen a fold of well-washed muslin with rubbing alcohol or unflavored
vodka. Raise the presser foot to open the tension disks and put the damp
muslin between. Lower the presser foot and pull the fabric through.
Repeat.
Finish up with dry, much washed muslin and try threading up again.

The other two mechanical causes I've seen of intermittent upper tension
problems (on other machines, not yours) have been bad tension spring
and a catch in the release that causes the disk to close when you drop
the presser foot.

Do you always raise the presser foot at the end of the seam, and then
lower
it to start a new seam, and then the machine misbehaves from the start?
Or does the problem ever start in the middle of a long seam?

The first case would suggest spring or presser foot connection problems,
while the second sounds more like upper tension cruddlies shifting around
and making mischief.

Oh, and is your presser foot properly attached? I did see one case with
an
old slant needle machine where the foot wasn't on quite right, but it
jammed
enough to allow decent fabric transport. But it wasn't letting the bar
holding
the presser foot drop enough to engage the upper tension. Remounting the
foot cured the problem. That was one of those headdesk moments....

Kay, amateur sewing machine mender