I started this project with an RC model.
It performed moderately well and so I decided to proceed. Built rudders first.
And simultaneously working on an engine mount.
After checking prices on various cage materials I decided on 3/4" aluminum electric conduit. I was told it couldn't be bent. But I found that to be totally erroneous. It bends quite easily.
Put the aft deck together.
Bought 2" 1.5 lb Styrofoam sheet. And with a few judicious cuts and lot of glue.
This is designed to be a lightweight build.
Laid down graphite fabric on the deck then turned it over. Got a couple of Elders from the Church to help with the graphite on the bottom. It laid down nicely over the curves.
Bought an Ultra Prop and Lifan 15 HP engine a seat a few other items and put it together with the help of a friend who is a lot stronger than I am. Puting the 83# engine on the engine mount would have been difficult. At this point the airboat weighs about 230 lbs. The deck is coated with 2 layers of epoxy tinted titanium white. The bottom is coated with 2 layers of epoxy mixed with graphite powder. Graphite power is a powerful tint and it makes the bottom slick, so that damage is minimized sliding across rocks and logs etc.
Bought a basic trailer and bolted some bunks onto it. It rides really well.
Had a difficult time finding where I could register this airboat in decent time frame. There is no TPWD within an hour of Stephenville. Ended up driving 93 miles to Abilene to get it done.
Then Friday 1/23/2020 I maidened this mini airboat. First trip out, well it floated. Never got it to plane and it was obviously tail heavy. Never got above 2950 RPM. Idled too fast to troll. One thing that worked well was puting it in the water and taking it out while keeping feet dry.
In the next week I moved the seat forward. Re-tuned the propeller to 11 degrees down from 12. Moved the gas tank to the deck out from in front of the propeller. Installed a fuel pump, fuel regulator and pressure gauge, after several days of research some miscues.
Disabled the governor and made the carburetor direct control. Reduced the idle RPM.
Fuel system
So I took it out Friday 1/30.
There was too much wind to hit full speed but I did get it up on plane for a bit. Have to be careful to keep some power on or the wind will whip the rudders around.
Saturday I took it out again. Some wind but found a flat piece of water and ran it up to 16 MPH per GPS. That seems fast sitting so low.
The gas tank is temporary. I have a custom aluminum tank being built. And some more tunng to do.
Rudders are on the pedals and the throttle is on the right hand.
Fuel pump switch and starter switch are on the left. Kill switch is on the engine frame.
The digital tachometer (13 bucks) is inductor. Just wrap the end around the spark plug wire. Cable was too short so we soldered another 4 feet onto it and it still worked!
Still have some tuning to do. And bells and whistles.