Does anyone have experience with blower fans? I want to find a fan strong enough to levetate a ping pong ball and then control the speed of a fan so i can move it up and down. So far I've tried a few computer fans and they aren't strong enough, but the more powerful ones seem super expensive. Below is the type of fan I am looking for.
http://www.kr4.us/blower-squirrel-cage-12v.html?gclid=CIXG1o36qs0CFdgIgQodRNwIaQ
How did you use the PC fan? Using a 100mm fan concentrated into a 25mm tube should work.
Simply trying to float the ball over an open fan is unlikely to work.
Weedpharma
The back-pressure rating of the fan is important here, it limits the speed it can accelerate
air to in a funnel (back pressure is created accelerating the air). Otherwise as pointed out
you have to direct the airflow to get a narrow jet. Try an actual funnel.