I recently purchased a new Consew RB-5 and have been pleased with it, however, recently I have had trouble with it skipping stitches. I was sewing leather with it with 207 bonded thread and a #23 needle. I have even switched to 138 with a 22 needle and it still skips stitches. I have included a photo of the leather I was using before it started acting up. I am certain that it is threaded properly.
Also, I wound bobbins today to try the smaller thread (obviously running at a higher speed) and after completing that, I attempted to sew and a small screw (pictured) fell off of the machine from somewhere and landed in the front of the machine. I can't figure out where it came from. It is very small and doesn't appear to have come off the exterior of the machine. Any help would be greatly appreciated.