"3D printing a LED diffuser directly on PCB"
Yes, it is possible. Hence this quick blog post.
This lamp is a simple proto PCB with a whole lot (>30) of high brightness 0603 white LEDs soldered on them with a few layers of 3D printed yellow PLA on top of them.
I had to add some DRAM heat-sinks to the back to deal with the massive heat production, especially given that PLA gets liquid at relatively low temperatures. Light production is quite poor, but it is cool for mood lighting.
To be continued.