My Model Hovercraft (2nd Gen)


This page is dedicated to a model hovercraft I'm building based on the last model hovercraft I built. The last one was successful enough but too heavy. This one is built from 1/2" 'pink' foam. I was a little more hasty building this one than the last and thus didn't pay as much attention to detail.

The small pictures below can be clicked on to see a larger image.

The Model's Construction

As you can see, this model looks strikingly similar to the previous. In fact, it's pretty much identical in dimension. It's driven and controlled by the exact same equipment that drove its predecessor which I cannibalized for parts... not a pretty sight (RIP).
This has the same dimensions as the last but I still had to make everything for the body from scratch such as the skirt, the motor mount, and the top. After contemplating for days how to attach a nylon skirt to a foam hovercraft, I finally decided to simply masking-tape the skirt to the hull. I've had this model running for some time and haven't had a problem with this method. That foam step you see in the middle of the craft is what the servo compartment rests on. I cut the foam parts with a hot wire and glued them together with epoxy. When the hull was complete, I glassed the outside with 1.45 oz/sq. yd. cloth and epoxy resin.
I had to completely redesign the motormount to be foam-friendly. Basically, that required attaching it to a piece of 6"x6"x1/8" plywood with screws and then epoxying the assembly to the foam. Notice that the rudders are now mounted directly to the motor mount instead of on a seperate mount (one less part to break).
This is a bottom view showing the base of the skirt attached to the hull via 1/8" x 1/4" basswood sticks used as the skirt attach strips. Currently, I epoxy a strip to the hull, lay the skirt over it, and then screw another strip to that strip. The problem is that the strips total over 1/4" high when I'm done. I'm probably going to modify this system by epoxying a 1/16" strip to the hull and screwing a 1/16" plastic strip to it to hold the skirt.
This bottom view of the front-left corner of the model shows the 5/8" diameter air feed holes for the serial airflow system. I used contact cement to attach a circle of screen to the inside of the skirt so that debris is not allowed in.
I made the top by cutting a styrofoam plug in the shape I wanted for the top with a hot-wire, glassing the plug with epoxy resin and one layer of 1.45 oz/sq. yd. fiberglass cloth. I then ran a strip of 6 oz/sq.yd. fiberglass tape around the outside edge of the outside edge to form a strong lip. After it had fully cured, I hacked the foam out with various sharp instruments and disolved the foam that remained with Acetone (nasty fumes... use a respirator and do it outdoors).
This frontal view shows the large gash that I had to repair on the starboard side of the craft. The fiberglass is very light and rather strong but not strong enough to stop a falling hot-wire power supply. ;-)
I forgot to take a picture of how I fastened the top to the bottom. I cut out pieces of plastic tubing, sliced them long-ways, and then 'clipped' the lip of the bottom to the lip of the top and stuck a pin through the tubing, top lip, and bottom lip to keep the clip from popping off. Seems to work.
Here's a couple of views of the engine and engine mount. Notice that I'm using nyrod to actuate the rudders this time rather than a push rod.
This is the fuel/electronics compartment. The servo on the right actuates the rudders and the servo on the left is for the throttle.