Many a times a design which sewed out perfectly in the past, just doesn't sew  out good enough - this could be caused by an improper size needle or blunt needles.

Needles and threads have a size number and thickness respectively - if these mismatch, then there will be lots of thread breaks and various other issues affecting your embroidery.

Blunt needles are a major cause of thread breaks, because when the needle wears out there are shards of tiny metal protrude from the tip of the needle and are as sharp as razors, they either peel or cut the thread - use a magnifying glass to see for yourself.

So, the burning question remains - how often should one change the needles?

Needles on a multi-head machine wear out according to the colors being run through that particular needle - for example if you have a jacket back design with a fill and a border - the needle used in for fill will wear out before the needle sewing border.

Cheerios.

 
Bobbin Issues 12/02/2008
 

Bobbin plays a very crucial role in embroidery - it is the thread which runs under the fabric, creating the knots and keeps the top thread from unraveling -  of course,  the digitizer also needs to  tie in and tie off the first and the last stitch on an embroidery object as well to secure the embroidery.

There are instances when bobbin thread, which is white in color 99% of the times, shows on top of the embroidery and plays spoil sport - so, here are the reasons that you should look at, that could be causing the bobbin thread to show on top.

1. The tension of the top thread is too tight, pulling the bobbin thread more than its supposed to and dragging it above the fabric.

2. The screw located on the bobbin case is loose and is releasing more than required thread.

3. If both of the above reasons have been taken care of and still you face this problem, than reversing the direction in which the bobbin rotates, while feeding the thread, could also help.

Happy Embroidering!