A fresh breeze

[foehnsturm 967]

Whatever fan duct you'll use, I'm not entirely convinced by UM's part cooling design. Especially when there are tiny structures  somewhere und you don't want to multiply parts just for cooling reasons.

Some might know my "Crossflow fan approach".  This one is the exact opposite when it comes to complexity and costs

A battery, a micro-drone replacement part for less than 5 € and some spare magnets. Just clip it to the frame where you need extra cooling. A 2000 mAh battery should be good for 6-8 hours.

If you are inured to the crappy version of the hotend cooling fan it won't disturb you much

If not: it only has to run during critical sections of the print.

[foehnsturm 967]

The robot file that comes with the printer. No left ear issue anymore.

[SandervG 1,352]

You should print a bunch of robots on different locations on the bed to see if the effect is the same everywhere.

But I guess the robots in the back will be hidden from the fan?

[foehnsturm 967]

I can move the fan along the X axis in order to aim at the "hot spot". If there were more than one, far apart from each other I'd have to use a second fan.

Of course the air flow is stronger close to the fan. But the basic idea simply is, throwing as much air as possible onto the print and don't care about the details I could even add a second or third battery, the fan is rated for 3 something Volt. But that would literally blow everything away - and sound like a real drone flying next to the printer.

[neotko 1,413]

Since it probably doesn't weigh much maybe you could clamp it on the shafts that goes on the inside so it automagically moves with it

How much air can that move? Maybe that could be a sollution for the air inflow (with tube) that you used long ago on the old old fan redesign on umo (the one ditched when you used crossflows). Maybe two-three of them with a voltage near 24v could be installed.

Or lol it would be even fun to have a small tube floating up above the heat, moving in the air and one bigger pushing air down through a tube to the fan area