I have a Bernina 950 Industrial bottom stitch loose and pulls out

What model? 217? 117? 950?

https://issuu.com/alicebernardo/docs/bernina_950

Free online manual

Bernina Industrial 950

Be sure you do not have a bent needle and or a damaged shuttle, if the latter, one should really polish the shuttle and oil it well as if the shuttle is dry at all you will experience similar problems
wayne Buss
[email protected]

Is your bobbin case a genuine Bernina bobbin case? If not, replacing the bobbin case will solve the problem. It is a common problem to find a Oriental copy of a bobbin case in a Bernina machine for a number of reasons, such as where the casing was swapped by accident or intentionally. Most often, repair technicians don't know the difference and would rather pay $7.00 for a Chinese casing rather than $56.00 for an OEM casing. Whatever the case may be, if the machine tension nests on the bottom side, stitches erratically, or breaks thread, changing the casing can solve the problem.
The bobbin cases may have similarities but there are subtle physical differences that prevents thread escapement over the bobbin case.
Much more information would be needed in order to discover your problem, however.
Other problems can occur by incorrect starting of the machine such as beginning sewing by holding the top thread rather than turning the machine hand-wheel in the direction so that the take-up lever is at the highest position. Machines like the 1005 do not have an automatic "Needle Stop' function.
There can also be similar problems if an industrial cone spool is used where thread is being pulled off of the spool's side rather than from the top center of the spool.
If the bobbin case is an OEM casing it is possible that the "loop lift (needle and sewing hook) timing" has been knocked out such as having had a collision of the needle with a button, zipper, straight pin, etc. Bernina 1005's and all of the newer machines are not constructed in such a way that would prevent this from occurring. As mentioned, more information would be needed here.
SewTechnical Home

try changing the needle--flat side to the back of the machine
the needle & thread & fabric have to be compatable
light weight fabric requires a different needle than medium to heavy weight fabric
if you do not have a manual check with bernina customer service about one
or
sewing partsonline.com
try a top tension of 3 or 4
clean under the needle plate & in the bobbin area for loose thread or lint

Are you absolutley sure you're not getting a problem with stitch formation on, for example, wide zig-zag. Check again, using a different colour top and bottom and make sure that the stitch is being formed properly with only the top colour on top and bottom colour on the bottom. It sounds as though the bottom loop is not being picked-up by the hook properly. Make sure you've thoroughly cleaned-out any fluff under the stitch-plate and remove the hook/shuttle and give the hook race a good clean and give it a single drop of oil, even if you've got the lightweight part-plastic hook/shuttle fitted.

Sounds like you may need to have the tensions adjusted. If the bobbin thread is showing on top, the bobbin tension may be too loose. If the top thread shows underneath, the top tension is probably too loose. Since you are having both problems, perhaps a technician should take a look at it.

I found a screw on the bobbin case (where you put the cotton for the underside stitching) which was very loose. I tightened it and that created more tension for the bottom thread which solved the problem.

This sewing machine looks exactly like the Berninas that I own, although my are not industrial. You just use the dial to make each side of the buttonhole, only having to set the stitch length to super small. The way you make buttonholes is this:

Think of the buttonhole as a square-ish capital O, with the center of the bottom of the O as the point where the button shank will lie when buttoned. Place the marked buttonhole area under the buttonhole foot, with this bottom point directly under the foot, squarely in the center of the 'hole'.
-Turn the dial to 1 and the long left edge will sew in zig zag stitches; stop the machine at the top of the O.
-Then turn the dial to 2 and the top edge of the O will sew; stop the machine after half a dozen stitches.
-Turn the dial to 3 and the right edge will sew; stop the machine at the bottom of the O.
-Turn the dial to 4 and the bottom edge of the O will sew; stop the machine after half a doze stitches.
-Turn the dial to 5 and run half a dozen stitches; this is a line of straight stitches that will 'tie off' the buttonhole.

Try this with a plain piece of fabric. Just put the fabric under the foot and dial away. You'll see how the stitches stitch.

I'll send a copy of instructions from my manual to you if you want. Email me at: [email protected].

Sometimes when I need to use heavy thread for top stitching to reinforce a seam that has come undone, I will use the heavy thread on the top and regular thread on the bottom. I haven't tried it the other way around for hemming but I would think it would work. I do not currently have a Bernina.