Anycubic i3 Mega Ultrabase driver cooling duct (ultimate)

Hi,

I have i3 Mega UltraBase with TMC2208 drivers. Designed and made this duct https://www.thingiverse.com/thing:2773533 for it. It was ok, until I went to Marlin 1.1.8.

I was able to reach higher speeds (Linear Advance) and accelerations. But, my driver cooling was not enough. After ~10min printing, layer shift appeared and reason was heat. i3 Mega's frame is not perfect to remove hot air from inside and previous driver cooling duct did take in hot air inside of chassis.

New design tak