Toolhead!
As stated previously, this is made out of CNC machined aluminum.

I started with a simple sketch defining a triangle that is circumscribed around a 59mm circle. Why 59mm? That was the smallest number I could get that still left space for the arm joints to do full range of motion without colliding. Weirdly specific, I know.
The center hole is for the hotend.

That gets extruded, sides get filleted, and the joints get added with tapped m3 holes for mounting. No double shear should be needed since I am mounting to metal.

Next was duct. I started by making a rounded cutout in my effector that I want as the start (well, actually midpoint ish, you will see) of the duct and a square I want as the outlet.

I moved this square to align with where I want the air to go. The sizing of these was somewhat arbitrary, with the main design constraint being matching a certain cross sectional area - a gentle taper down to 70% of the inlet. So if the inlet is a 17mm circle (19mm hose with a 1mm wall), tahts about 230mm^2 I get to play with. 70% of that is 161mm^2, which is about what my outlet is.

You may be thinking, shouldn’t that outlet be a lot smaller to account for the air stream being split into multiple ducts??

No.
I will be running 2 ducts. Each duct has its own hose and blower. That’s right, dual cpap.

Next is a loft with a curved centerline. This gets me my duct!

Then it gets mirrored to the other side of course.

At this point my friend was like. You know, having 3 ducts would make it symmetrical/match the delta-esque shaping. Triangles and such.

But having 3 CPAP blowers would be silly!! Absurd even!!

I love silly.

Triple duct, triple cpap. I will NOT be limited by cooling.

Next is a little top plate for mounting the hotend.

This guy just takes 3x 30mm M3 standoffs, super simple. And it’s all metal, so hopefully rigid af.

Another sketch and extrude gets us an extension to the top plate. This is for holding the 3 cpap mounts.

One more loft, extrude, and circular pattern gets us the upper section of duct.
This is connected in one ring. The whole thing is mounted purely by compression from the upper plate and the effector through the standoffs - no additional hardware. It makes things rather clean.

And that’s it! Kinda. I need to figure out how berd air hotend cooling works since I don’t want a fan on the toolhead. But I don’t even know if that takes any additional cad? We will find out!

This thing is silly. It’s crazy overkill. It’s bonkers. I love it though. Really sets the tone for the rest of this printer.