Irregular bottom thread!?!

Hey all!

I am currently making a bag and am having some issues now that I am stitching the handles.

 I am sewing straight lines on some cotton canvas. the top thread comes out perfectly straight but the bottom thread is very irregular. I have cleaned the bobin area, increased the top thread tension but nothing makes it better.!?!

Any tips??
Thanks

Have you tried changing your needle to one size up?  Handles are usually several layers thick which means the needle has to punch through all layers quickly.  If it's having any trouble getting though, you will have crooked stitches.  A little tension and needle adjustment should do the trick.

Needle change and my machine has a specialty bobbin case where I can adjust the bobbin tension independantly. Works wonders for super light materials and when sewing through serious layers.