Garage Hack: Hovercraft

My son Cameron has been asking me for months to help him build a hovercraft (hey, he's 10 years old, so that is a valid request), but I figured it would be too complicated or expensive, so I kept putting him off. Then, while looking browsing around researching something completely unrelated, I found site which had some project plans that seemed easy enough to build, so we started searching through the garage to see what else we would need. As it turns out, the site I found had copied the plans from here, so I changed my link to the original plans (see Bill's comment below this article).

I didn't want to buy or cut a round piece of plywood, but I did have this old laminated countertop left over after a kitchen remodel, so I decided to go with a rectangular base:


The only tool I had to buy was a hole saw to cut the main air passage:


Here is the base after cutting the hole:


The hovercraft uses a leaf blower and I didn't want to permanently mount mine to the base, so I glued a short piece of PVC pipe into the hole using Goop glue (that's me holding it):


A few people had said they had to lift the edge of their hovercraft to get the air to flow into the skirt, so I thought I'd make the process easier by using some stick-on felt feet to ensure there was a gap between the board and the floor:


Next was to staple thick plastic to the base to create a bag on the bottom. I'm not sure of the exact thickness of this plastic as it was a left-over roll I bought when mounting a DDR pad to a plywood base. The idea is to pull it flat on the bottom, then staple the top and seal it to make it air tight. The plastic was much stretchier than I expected and I'm not sure if other plastic sheeting materials would have a different elasticity.

Stapling the sides:


And the corners (I folded it over like I was wrapping a package):


Here is a completed corner:


Now the plastic is secured, but not sealed, so we trimmed the plastic to about 6" using a razor knife, then used duct tape to seal it down. First construction mistake: When we first inflated it, several of the staples pulled loose, so we wound up re-duct taping it, then re-stapling through the duct tape. In retrospect, we should have just tacked it down, trimmed it, then duct taped it once, then stapled through the duct tape instead of doing it all twice. The staples through the duct taped plastic are very secure and haven't pulled out yet.


The original, round, design used a plastic lid as a plate on the bottom to shape the air bag/skirt. Since our platform was rectangular, I cut a proportionally smaller rectangle out of plastic, covered the edges with duct tape to prevent the bag from tearing, then secured it to the center of the bottom, over the plastic sheeting, using wood screws. Second construction mistake: Our air bag/skirt is a bit misshapen and drags a bit on the floor. Version 2.0 will have a bottom plate that is a 3.5" x 2' strip of wood so that the air bag is the same width all the way around.


Here is the bottom of the hovercraft, complete with everything except for the vent holes:


I cut six vent holes near the retaining plate on the bottom, using the head of a mini-Maglight as a template. I'm going to experiment with more holes before I remove the plate and plastic to improve the bag shape and I'll report back on what seems to be the optimal number and configuration:


Now, it is ready to test. Here is my son Cameron waiting for the first ride. I thought I'd better snap a picture in case it ripped itself apart on the first run. To the left you can see the plastic lawn chair that I'm eventually going to mount on the deck. Also, we're going to build a small frame to hold the leaf blower in position, but right now it's just duct taped to the air hole (which is actually quite secure):


Power on... It works!! The bag inflates to about 5-6" off the floor, easily lifting Cameron (the felt pads worked great). When the bag inflates, it feels like you are floating 6" off the floor. The bag shape isn't perfect, so it tends to vibrate off the floor (making a loud screeching/farting noise), but if you shift your weight, it actually floats about 1/8-1/4" off the floor and glides freely. It is, however, very loud. I've got to get a lower angle picture to show the levitation height, as it isn't apparent in these pictures. It works on low or high power settings on the leaf blower with very little difference in lift, so the design is quite forgiving:


We all had a ride and it even lifted me with no problem and I weigh over 200lbs. I'll spare you the picture, but here it is with two riders (Cameron and a friend) whose combined weight is around 200lbs (note the hearing protection -- the friend is wearing ear plugs). The platform itself is fairly heavy:


My daughter had a ride, but by now, hovercraft rides around the garage floor were becoming passe:


So, there you have it, a hovercraft built over two evenings in my garage out of junk I already had on hand. I'm not going to be riding it down the street or across a pond anytime soon, but my son was happy. We gave rides to most of the kids in the neighborhood and it definitely earned me some "Cool Dad" brownie points.

Next Steps

Rebuilding the bottom to make the bag more evenly shaped (an oval would be perfect)

Testing different numbers of vent holes and vent hole configurations

Mounting a plastic chair to the frame

Seeing if we can use a handheld floor fan to propel ourselves

If the fan works, mounting it to the rear with a steering mechanism like an airboat

Seeing if we can get out of the garage if we use a gas-powered blower

Complete set of photos, in various resolutions, can be found at cmpalmer.smugmug.com. For one of my other DIY projects, check out my Beakman's Electric Motor page.

If anyone else builds, or has built, a similar hovercraft or has any questions, please post a comment...