|Project by Jim Jakosh||posted 12-06-2009 08:30 PM||6253 views||7 times favorited||23 comments|
This is a hovercraft I built from the plans from Universal Hovercraft for a 15’ hovercraft. I had a girl in Engineering expand it on CADAM to make it 12” longer and 6” wider. Then she did many development views to get the ribs the right length for it to look right. Anyway, it was big wood project with pine and marine plywood and West System Epoxy. I flew it for 10 years before selling it. It started out with a Rotax 503 2 cyl engine and then got a Subaru 1800 4 Cyl engine.
It starts off with a frame of very long 3/4” square stringers screwed and glued to the ribs held in position on the 2×6 fixture. Then it is “skinned” with 1/4” mahogany plywood on the bottom and 5/32” mahogany plywood on the sides and top. There were round wood forms made to consturct the lift fan duct up front and the cavity between them was filled with 2-part liquid styrofoam.
The props were rough made by Bob Windt at UH while I waited. He had pine 1×6’s stacked up and epoxyed together. Then he draws a line down the sides and runs them through the band saw and they are really close to being done. I had to finish sand them and fiberglass the outer surface and balance them
The drive pulley on the fan was made from hard maple and I had to turn it in the lathe at Steelcase because it was too big for my lathe. The elevator and rudders were aluminum wrapped over cedar airfoils.
. I used a thinned mixture West System epoxy over the entire surface before painting it. The nice thing about West System is that it penetrates the wood about 1/32” so it makes the ultimate wood joint.
I had made a plywood template for the engine mount before actually making the steel one.
Sewing the neoprene coated nylon skirt was a big job and the repairs to it were part of the reason I sold it. It took a beating.
-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!