my laser https://www.youtube.com/watch?v=B2z9Ja7nIeg
my home works http://tribiamarco.altervista.org/
Facebook Laser Cutter Tech Support: https://www.facebook.com/groups/lasercuttertechsupport
I read that someone recommended Shenhui and although they had a good reputation in the past, I now have my doubts based on the fact that they didn't bother to respond to my enquiries for one of their machines. Several times. Maybe because some good qualified 'laser' staff left that company some time ago and went to their competitors.
And give it a thought to wait with ordering / paying until half february because from end January not much will happen in China for a few weeks. And if you finally decide to buy a Chinese laser machine, order and pay it through the Alibaba buyer's protection program (is a bit like the Ebay/Paypal protection). Good luck with your search.