I use a Replicator 2 and often print on the original acrylic build plate. I've found that I have a lot of success getting my prints to stick to the plate if I wait to enable the down fan until I've put down a few layers. I've made a small change to cool.py that I'd like to contribute to enable users to choose when the fan is turned on. Is there a public repo for making code contributions? If not,by kyle - Skeinforge