Mark Fickett Art: RC Hovercraft

Finished Hovercraft

hovercraft front hovercraft side hovercraft bottom

The skirt is like a slanted round tire, filled from the open side where it's attached to the hull. Air escapes through vents and along the seam between the skirt and the bottom of the hull to form an air cushion under the hovercraft .

case fan

The case fan which pressurizes the skirt and air cushion.

propeller linkage

The linkage between the micro servo and the propeller support is a bent paperclip. The propeller is mounted on a section of shelf standard, which in turn is on a bearing scavenged from an old hard drive.

hovercraft on water

Inspired by RC Test Flight's trash bag hovercraft.

Improvements

Modifications to this design

Although turning the propeller (instead of using rudder vanes) is atypical, it worked well.

Alternate design

Many hovercraft, especially small racing hovercraft, have finger skirts. They also feature a bow partition and a rear flap. Various RC hovercraft have also been made with this design.

References:

Parts

Most of these were spare or repurposed parts.

Part Cost / Source Notes
Motor: Turnigy 1450KV Brushless $20 from HobbyKing This motor was way overpowered for this application; I stayed almost exclusively at ~5% throttle. It, the propeller, and the ESC were purchased for a plane.
Propeller $2 from HobbyKing
ESC: Turnigy Plush 60A $35 from HobbyKing
XT60 Battery Connectors $3 from SparkFun for the battery &damp; ESC, and to make an extender between the ESC and battery with a splice in for the case fan
Case Fan $26 from NewEgg 120mm fan, provided ample air pressure and flow, rated 2A@12V, 190CFM, 17.8mmH2O, 370g (specs at DigiKey)
Servo Motor $10 from Adafruit
Paper Clip linkage from servo to shelf standard with drive propeller
Shelf Standards ~$3 from a local hardware store
Bearing from an old (~100MB) hard drive actually the HD motor, but had convenient mounting holes / screws
Cardboard free / scrap
Plexiglass, wood block free / scrap used to make a rigid mounting structure for the steering assembly
Nuts and Bolts $5 for 6-32 socket-head machine screws and matching nylock nuts from servocity.com
Trash Bag (33 gallon "outdoor" bag) 25¢ ($5/20) for the skirt; showed no obvious signs of wear from use on asphalt after a couple hours
Duct Tape
Spray Paint white base and clear protective finish; for water protection

And, shared with other R/C vehicles:

2.4GHz RC Tx/Rx $30 from HobbyKing only 2 channels used
12v LiPo Battery (5AH) $30 from HobbyKing sufficient for at least an hour running the hovercraft; a smaller battery would work just as well
LiPo Balance Charger $25 from HobbyKing

Construction

frame pieces

Frame pieces cut out.

frame glued

Glued and clamped.

frame painted

Painted.

corner mock (inside) corner mock (outside) corner mock (unrolled)

To join the cylindrical segments of the skirt, the edges of the flat plastic sections must be cut as a sine wave.

cut plastic

Frame with plastic cut for skirt. I used many short pieces of duct tape to join the curved seam between the plastic sections.

2014-09-06

In: Misc