[Good "show off" prints to excite students?]

Hi,

You can't go wrong with single prints that move such things as gears or gyro's.

https://www.youmagine.com/designs/arc-gimbal

We used this one at Makerfaire UK and is a short print and kids, teens and adults loved it because they don't get how it prints the mechanism.

https://www.youmagine.com/designs/modified-space-wrench

NASA space wrench is always a good one for the same reason and it's printed in space.

[After insulator change , both side fans are not working, now.]

The solder and longer wire could be causing slight lag but I've never seen a problem like it.

It may be worth contacting Ultimaker to see if you can buy a fan pack. I work in the UK

so I am not sure of the shipping cost for Canada. It may be worth in the long run buying some

better fans.

[Cura shows differnt to print]

Can you check the file In layer view in cura? It may look fine on the normal view.

Does it fit the build volume with no problem or is it really close to the edge?

[Feeder goes crazy (iper rotation) when starting a print]

I would make sure the firmware and cura settings match. Make sure it is updated for the correct machine. Also I would clean the feeder and knurled wheel with a wire brush

[Missing one exact layer]

I would try cleaning and re lubing the z axis. Maybe double check in the layer view in cura and check the file. Also making sure the firmware matches the cura version you are using.