I designed this vent redirector and extender because I was unhappy with the commercial options available for a long extender.

I had to divide it up into 6 sections. I was not happy with the results when I glued them together, likely due to uneven cooling and shrinking. So I designed a friction clip to slide them all together, which works pretty well, though it can be a little tricky with 6 pieces. The curved one was a bit of a challenge in Tinkercad and makes me want to learn something more powerful. There are still some gaps, but not enough to lose a significant amount of air. I designed it so the friction clips can be printed vertically without supports, though the thin contact area probably requires a brim, which I use by default.

With a large format build plate like the Monoprice MP-10 or Ender 5 pro, the redirector and extender could be printed all in one go, greatly simplifying the design an assembly, so I included those as well. I have not printed them, so I can't vouch for them. But for those with a normal size bed like myself, I have included the individual 5" parts.

My vent is 11" x 5". This could be reasonably easily modified to accommodate other sizes with a little work. I also needed a 10" extender, so I split that up into 5" sections.

Yes, I had to work in imperial units because that's what my tape measure had. This will be the last time I do that though, what a pain.

In retrospect, the extender could have been done with some printed clips and a commercial sheet of plastic, but when you have a 3D printer, everything looks like a nail. It's also 1/8" thick, which is likely overkill, but it works. I put some magnet tape on the bottom of the redirector, which raises it up a bit, but on carpet it all evens out. On wood, the redirector might have a slight gap depending on the thickness of the magnet tape.

It's important NOT to use PLA, as the furnace output can be warm enough to warp it. I used PETG, which is almost as easy to print as PLA. I thought the clear stuff looked cool with the gyroid infill. I imagine 100% infill would be clearer (especially if achieved by increasing the perimeters rather than infill), but slower and less material efficient.