spring inside bobbin case question

[FloridaMissy]

I have a question in regards to the backlash spring inside the bobbin case.  I often remove this and use the prewound magnetic bobbins from filtec.  I have been winding my own more often lately.  Do my test on tension and start quilting only to have a minor little thread that pops up.  Doesn't happen very often.  All the rest of the stitches look perfect until I took the quilt off the frame.  Where each of those little raised stitches are I have a pretty nasty birds nest on the back and then the stitches look perfect on the back etc.  I am assuming I'm getting bobbin basklash.  Can you tell me the correct height of the little arms in the spring should be?  Or do you think it is a different problem.  Thank you everyone.

[SueD]

Do you have just one bobbin case/spring?  If so, you could purchase another bobbin case and some extra springs.  The L size are $12, the M size are $54.  Extra springs are $3-$4 each.

You should be able to see & feel the effect of the spring when the bobbin is in the case.  You should be able to squish it down a bit and feel it pop back up - you know, springy  .  If not, you could try adjusting the arms on the spring and see if it helps.  

Also, have you tried different bobbins?

[jimerickson]

Missy:  If you have the backlash spring properly installed in your bobbin case, then it's an issue of tension.  You need to tighten cone thread/loosen bobbin thread tension 'til you get a balanced stitch.  If the tension is so much different from magnetic to backlash spring bobbins, I'm guessing you don't have the backlash spring properly installed in your bobbin.  In my experience, removing and reinstalling backlash springs is something I don't like to do.  Getting them properly installed is a bit hit and miss.  I agree with Sue's suggestion of buying a second bobbin case for use with your studio wound bobbins.  Now both my machines have M bobbin systems and they might be more difficult to switch around than the L's.  I don't know.  But for my own convenience I'd invest in an extra bobbin case.  Good luck.  Jim