Needing something "light" to build, I dug out the original Skimmer airboat design. This was intended for use with SPEED 400 motors and small battery packs. Something larger that would suit 500-600 size motors and the popular sub-C battery packs was needed. Figuring out that the new model would be double the weight of the original airboat design just gave me the problem of how to "double up" for the model. In the end a modest increase in size, about 19 inches (48 cm) length and 8 inches (20 cm) beam seemed suitable.
The construction is mainly 1/4 in (6mm) balsa with a 1/16 in (1.5 mm) plywood hull bottom (to cope with all rubbish likely to be floating about). Care was taken to keep the edges of the hull as sharp as possible to encourage water to break away and produce a clean running hull.
This type of airboat benefits from a driver figure. To keep the top weight down and aid stability, a figure was made from EP foam with a table tennis ball head! Not exactly handsome, in fact something more like a product of Dr Frankenstein's laboratory, but looks OK when sailing.
Replacing the mild 540 motor fitted for the first runs with something more "pokey" had the model performing as an airboat should. Straight runs are fast, stable and create little disturbance in the water, hence its name, whilst high speed turns are taken in a wide sliding fashion with little loss in speed. This does take a little getting used to and needs a large area of water. The sight and sound of these models also adds to the fun.
Too tight a turn can result in the hull side "digging in". The resulting deceleration and spray thrown about is more spectacular than dangerous. The light driver figure helps here!
Plans now in the hands of the Editor of Model Boats. I'll carry on skimming whilst thinking about the next model.
Glynn Guest
Author
Topic: Skimmer 5/600 (Read 2065 times)