Hmmm . . . based on my experience of helping people the Singer (and others) overlockers from Aldi / Lidl that people have brought to class, I struggle to agree with your tech Brenda P. I wonder how many s/he has used out of the box.
The issue for me is that these machines seem to vary so much and it's not the same things that have to be worked around to get an acceptable performance on similar machines. It's often a case of someone who knows what they're doing can coax the machine to produce a tolerable stitch or handle a troublesome fabric. Unfortunately that's often not the case with the owner who had anticipated beautifully trimmed and finished seam allowances but feels disappointed and frustrated when they cannot seem to get it to work properly. These owners are often experts at threading up their machines.
It seems to be a lottery because some of the machines work fine (although their owners can be disappointed when they realise the machines are designed for only light to medium weight fabrics and struggle with thicker layers or heavier fabrics). New owners who seem to have troublesome machines end up learning how to work around the nuances of their machines.
The main issues seem to be what I'd call mechanical set up issues -
At least one of the tension units is 'off' and has to be really dialled up or down, or just doesn't engage correctly or sticks. It shows up in different ways but the hardest one to resolve is inconsistent stitching when the locked edge moves over then under every few centimetres.
or
The looper/needle alignment isn't quite right - mostly it shows up on narrow finishes on finer fabrics with a size 11 or 12 needle.
or
the cutting knives really chew rather than slice the fabric.
Bearing in mind that they're all fixable by a tech who knows how to set the correct tolerances, what new owner wants to spend around £35 to have a machine sorted out when it cost less than £100 to buy.
Other than the knives issue (where changing out with the spare lower cutting blade usually works) it's a case of fiddling around trying this or that until the owner masters the learning curve to become quite expert at troubleshooting their particular machine. I feel sorry for the owners when they have to spend more time learning to troubleshoot than they do mastering the techniques.
[/size]When they work properly, then I agree people do get a machine that's worth what they paid for it.Only my experiences, others may have different experiences.