Thursday, May 01, 2008
Anti-ooze - the first design
Untitled from Adrian Bowyer on Vimeo.
Here is the new polymer valve in operation.
A solenoid pushes a short length of piano wire across the flow. This stops it instantly, giving a much better finish to constructed objects, and also stopping the polymer oozing from the nozzle when it is idle.
The AoI files for the design are in the subversion repository here. The solenoid I used is from RS: 250-0827.
I have also checked into the repository the changes to the host Java code and the firmware for the Arduino needed to drive the device. Note that, in the latter case, the new firmware disables the maximum (but not the minimum/zero) optoswitches on the RepRap machine's axes. Few people use these anyway, and - as pins on the Arduino are tight - it is better, I think, to use them to add new functionality.
Exactly the same code will drive the metal deposition head that I blogged here.
Labels: polymer extruder, valve
