One of our clients, Fritz, has been converting his ordinary extruder into a Bowden-style extruder which allows the extruder motor to be anchored to the RepRap frame and push the filament down a guide tube. Problem: Rigid PTFE tube is expensive. But we suggested Fritz try PVC hydroponics and irrigation tubing – and it seems to work well. So well in fact that we’ve got some free tube for our customers to try it out if they want to. Just let us know by e-mail with your next order.