the casual quilter

The kind thing to do would be to mention it and show her what you are talking about. You'll be helping her to be a better quilter and helping her to spot problems before a quilt is returned to the customer. It could be a machine issue, or it could be something as simple as running out of bobbin and not picking up in the right spot. Just my opinion.

mytwopals

There are a number of things, which can cause skipped stitches on a longarm. A couple have already been mentioned (Tension and machine timing). Additionally, three others come to mind (Backing or quilt top stretched too tightly, quilt sandwich too high above the machine bed and stitch regulator encoders not making proper contact to the rails).

While it is very important for your friend to understand how to set the timing and tension on her longarm, it is also important to properly set the tautness and height of the quilt sandwich on the frame. A quilt which is too taut will cause needle deflection and skipped stitches. A quilt sandwich too high above the machine bed will cause what appear to be tension problems and sometimes skipped stitches.

For the encoders, have your friend watch and make certain the encoder wheels havge proper contact and are turning at each and every place along the rails, both front to back and side to side. If there is any spot where the encoder wheel does not turn, stitches will be skipped at that point. The O-Rings on the encoder may be worn or the rails may need cleaning. This would only be a problem in Stitch Regulated mode. The encoders are not used in Manual mode.

mandyk

Could also be caused by using non regulated mode and jerky or too fast or to slow movement, especially on curves. Yes, I would want a customer or friend to tell me this, as it affects me ability level, and ultimately satisfaction with my work. Not everyone is going to be willing to make repairs. If unnoticed, that stitching could unravel. That would be a travesty.