It hovers!

In a very momentus event, my hovercraft took it's first flight today! Many thanks to those who were here and gave a hand keeping things under control: Adrian, Ayse, Eric, Jenny, and Wim!

Here are a couple views:

Top corner view:


Lower corner view:


And slow motion side view:

We did start with a fan test and we could see that the bag was successfully inflating.

 It's been a long time getting to this day. It's really awesome to see it all finally come together and hover. It's been a long project and I've gotten distracted many times by many things and pushed this project onto the back burner. But now it's hit a big milestone. There is still lots of work to add the thrust motor as well as better controls. Manually reaching forward and increasing the throttle is not optimal.

There was some excitement in the tests. At the end of the flight the lift fan did fall off of the engine shaft. That was the big bang at the end.

It did validate my design choice to use an enclosed metal duct. Despite the fan coming off while still spinning, there is almost no evidence of it being a problem. After disassembling it there were a few wood shavings in the fan housing, and the end of one blade is a little bit scuffed.

The scuffed fan blade having fallen off the engine shaft.

Wood chips in the bottom of the fan housing upon dissassembly.

The fan blad resting at the bottom of the housing after the first flight.

This reaffirms my concern about the loosening bolt from the previous tests. I'll need to look more into how to make the collet more robust to vibrations. In this case again one of the bolts had again loosened during the testing.

It was interesting that I think it only fell off at the end due to the positive pressure provided by the thrust. I suspect that part way through the test it had loosened enough to start slipping but it was only partially slipping and was held up by the back pressure.


As a side note upgrading the engine mount will definitely be valuable for decreasing vibrations as well as opening up more fan area for through flow. Right now the engine mount is covering most of the fan's surface area. With that more open it should be able to hover higher. It was adequate for this test on very flat ground but I think it will need more in the future.

I'll also take the time to add some more sides to the cockpit near the forward engine to stiffen it up.

The vibrations in the redwood are amazingly large in amplitude. They can be seen clearly in the engine test videos.