My friend has a machine with a bobbin winder on her machine but she insists on using her battery operated one because she finds it difficult threading the machine because of poor eye sight. Another friend can't understand why she uses it when there is a good winder on her machine. I have one and would throw it through the nearest window if I ever used it again.reason it makes such a mess of the winding and takes so long..we all have our own reasons to use what we do.