I've been carving Azek for two years now and it's a great product to work with....BUT it is very messy and loaded with static. Here's a link to a dust collection system I built to combat the problem. The Vac. shoe ( Azek ) was designed and milled using the Carvewright. The material being carved is also Azek.
http://www.youtube.com/user/Tegcnc
PS. All the marks on the roller pressure head in the video are the remnents of Duct Tape ( taping shop vac heads used to be a real PITA )