Berd Air Selector

thingiverse

Let's start with a [video breakdown](https://www.youtube.com/watch?v=rnl5iC12ndc). As we enter an era where tool-changing printers become the standard, we'll likely encounter obstacles as the cost of the machine increases proportionally with the number of tools. What if we could reframe the problem of tool costs as an opportunity to design shared infrastructure? The Berd-Air Selector is my initial concept for a compact, affordable solution for air cooling. This stepper-driven rotating selector enables us to reroute the aquarium pump's airflow to one-of 8 different tools. Since only one 3D printer head is active at any given time, this solution reduces the cost of air cooling expenses for every redundant extruder. Okay, so why not use cooling fans? Fans are the norm for part cooling, but fans are rather large, taking up a significant fraction of the total size of the extruder. The Berd-Air pump shines as a compact alternative. Unlike a fan that sits on the extruder itself, the air source is placed elsewhere remotely, and a small hose routes the airflow from source to the hotend. Unfortunately, aquarium pumps are expensive compared to mini PC fans, but that's where my selector comes in. This selector cuts out the cost where we'd otherwise need to add redundant pumps for our second, third, fourth, ... extruder heads. ## The current state of affairs: This is currently a work in progress, so I have yet to complete writing the software for this feature. Hardware-wise, however, it is almost entirely feature-complete. (My only addition at this point would be a homing switch.) ## Bill of Materials can be found [here](https://drive.google.com/file/d/1VrGQThiHIQzwDT3B4fPp4-dum1bjMd5n/view?usp=sharing) ## Design Notes * All moving surfaces that break-and-reconnect the airflow path are connected via rubber seals. This design features two seals: a laser-cut rubber gasket made from Santoprene and a small rubber O-ring. ## Assembly Notes: * The Delrin slip face must be lubricated with white lithium grease such that it slides smoothly