The GraffitiBot is now fully functional for printing graffiti although there is still a lot of room for improvement of the print head nozzles. It took quite a bit of work to get the hoses to curl properly without kinking. The kinks were making it difficult to purge air bubbles from the hoses.
It was also very difficult to get each individual nozzle to be clear and smooth. The pores are so small, any tiny whisker of plastic completely messes up the output. I have some tiny drills, but they can leave small whiskers and they are so delicate, I broke 2 of them in the manifold (and couldn't remove the broken bits).
I had printed and tested the manifold and nozzles early in the project so I knew they would be problematic. I ordered proper dispenser nozzle tips when I discovered the issues, but they have not arrived yet, so the machine is stuck with a pretty low performance nozzle arrangement until they arrive.
Here is a little video showing that the software is all working well and the pumps are working under software control:
I will try to squeeze in a couple of runs trying to print graffiti just to show what this nozzle set up can do, before doing a wrap up blog as this is the last day I can work on this design challenge.
GraffitiBot Project Blogs