Folding fan exhaust system .. where to start

[kevinrobson]

I want to create an exhaust system to attach to a fan to redirect the fan output. I'll be 3d printing it.

The simplest way to describe what I'm after is to point at this youtube example using the loft tool.

https://www.youtube.com/watch?v=7vBr1ztTeNA

However, in an ideal world it would be foldable, and made of several pieces piviting around a metal rod axis, with the smaller pieces folding into the larger ones. Think similarly to the attached flexible ducting, but maybe just 3-4 pieces that fold into each other for storage. Think like similar to segments in an orange, but hollow.

I'm literally not sure where to start. Is anyone aware of a tutorial video doing something similar?

Would you make the piece as per the attached video, and then split the pieces.

Or would you use the attached video to make each individual piece, but using slightly smaller dimensions each time (and af course a smaller arc)

I 'think' the last option would be the way to go. But I have fairly limited experience so keen to ask advice before I dissapear down the wrong rabbit hole.

Thanks in advance.

[wersy]

If the elbow is to be foldable, what material should it be made of?

If it is to be printed from flexible filament, a corrugated surface would be more suitable.

[kevinrobson]

I must admit I hadn't yet thought about how it would lock into place.

Either friction (which I believe you are suggesting) or some kind of plastic taps that lock into each other.

I'd assumed I'd design it to pivit around a metal rod, but not got that far yet.

I'll just be using PLA.

[wersy]

I was thinking of a flexible hose.

Something that snaps together is not airtight.
Why should it be foldable, do you want to save space when you store it?

[kevinrobson]

Yes, it's so it folds down small for storage. 

It's actually to make a window fan to push air from outside to the back of the motor home. 

[wersy]

If it is only blown through for ventilation, it may not be completely tight.
Perhaps you could use something like this.

[kevinrobson]

Yeah. That's the sort of thing I'm thinking.

Can you describe the method used to create, in as idiot-proof language as possible please?

Would you use the loft tool as discussed, and create several pieces with slightly smaller dimensions? 

[wersy]

Of course, you can also use loft, but revolve is the best option here.

I have changed the procedure because the segments seal better if the contact surfaces of the flanges are conical.

The most important aspect, however, was that the parts can be printed without support using chamfered flanges.
That's why the flange connection is drawn first in sectional view. There must be a slight overlap to the pipe bend so that there is no gap.

The flange is created with revolve.

The same method is used for the pipe segment.

In this way, you can work your way from segment to segment.

[kevinrobson]

Thank You.

I'm away at the moment but will take a look at this in a few days. 

I'd be lying if I said I fully understood (I'm a bit of a novice) but that definitely gives me something to start with.

Thanks