Science Buddies: "Ask an Expert"

Hello, I have recently built a hovercraft and we were trying to implement steering with a 2nd more powerful leaf blower, and it doesn't work. Is there a way we could do this low cost with the 2nd leaf blower? Thanks.

Conventionally, a hovercraft has a fan pointing backwards that provides forward thrust and vanes behind that to divert the forced airflow to the left or right. That seems to be something you could do with a 2nd leaf blower and some simple plywood vanes.

What did you try that "doesn't work?" Perhaps between us here we can suggest a fix for whatever you tried if we knew what that was.

We tried having the 2nd leaf blower on top of the hovercraft and the person would turn it to change direction which didn't work.

Where and how was the second blower mounted? In the middle with the rider? Near the edge? Most designs use a stationary fan blowing backwards and add vanes to slight;y deflect some of the backwards thrust. If you aim too much of that thrust sideways and you spin.

What happens when it "doesn't work"? Does the craft mostly spin in place?

By not working I mean it doesn't do anything.

It is also placed near the back of the hovercraft

If the rear-pointing leaf blower doesn't make the craft move OR turn, I can imagine it's either not powerful enough or that the craft isn't really hovering very well. A craft that's really off the ground will be easy to push in any direction by the touch of a feather. Imagine an air hockey puck. If yours isn't that easy to push around, then that could be your problem.

You could try measuring how much force it takes to push the craft when it's hovering, then devise an experiment to see how hard the leaf blower can push. There are a lot of videos of people who have got this to work, so there must be something basic you're overlooking. It's hard to tell without seeing what you have.

I could post an image, shall I do that?

A photo would be handy, as well as a drawing from the top - as if you were looking it from the ceiling. I'm also interested in how much leaf blower power you have and how effective the air cushion is. Other folks on the web that have reported problems found that they were just barely off the ground and still dragging a little.