problem with the threads connection
the sewing machine does not connect the upper thread with the lower thread
crwdns2934109:0crwdne2934109:0
crwdns2936751:024crwdne2936751:0 0
crwdns2936753:07crwdne2936753:0 1
crwdns2936753:030crwdne2936753:0 4
crwdns2959996:0crwdne2959996:0 90