Dumas Big Swamp Buggy

[greenman407]

[greenman407]

OK ...finally all installed. Now I need a day for testing.

[greenman407]

The hold downs are off the shelf "Traxxas" units, that I started with and I modified them for this boat. Because the Swamp buggy has a roomy open cockpit, it worked well. Other boats are not so roomy.

[greenman407]

Ive even gone so far as to build a tray that goes in the forward battery section, made out of sheet plastic, that securely holds a battery and the esc.

[trout]

That is so cool. The battery lockdown on your boat, makes me think about our subs. The installing of batteries and the way we pull them out and stuff them back in, is an area that could use some improvement. Maybe a frame for our tubes that mount to the bulkhead and the forward most end flips open, so battery changes could be as simple as drop in and close the end. Hmmmm I need to ponder on this. Thank you Mark!

[greenman407]

Next, we need a place to put the two Lipo batterys. In the cockpit area, I mounted two battery hold-down systems for............well....battery hold-down. Notice this neet, ready made plug for providing a series output for your two Lipos. They are also available in parallel. With that in place, I will be able to see the best mounting location for the ESC, and then we will move on from there.

[greenman407]

Humble beginnings.

[greenman407]

Youll notice three output wires from the ESC to the brushless. Its just like(sort of) the three phase 480 volt power that Im used to working with on the Job. AC power has a hot and a neutral, hot being HOT and neutral being the return path to the generator station. Well , in three phase power there is no neutral wire. The three individual wires are the Hot and the neutral..... each one, part time hot....part time neutral...but all carefully out of phase with each other so that there wont be any crowding of events. At anyrate...it works well and reduces worldwide the number of wires to complete a circuit. This is all an over-simplifacation....... but its all mine. At any-rate....thats how the brushless motor setup works. Hook up the three wires how ever you like. If the motor turns the wrong direction , just reverse any two wires.

[greenman407]

Wow! That was fast.

[greenman407]

Heres a twin. IDIOT.....................I thought that only I would do something like that.............................................. ...I HATE HIMhttps://www.youtube.com/watch?v=mNVPrdfpjOc

[greenman407]

Heres a Youtube video of a full size airboat. Its either an optical illusion................or that guy has some kinda clutch on that prop. Look at it.https://www.youtube.com/watch?v=p-QvyfnGQ1I

[greenman407]

75 Amps.....1000 Watts.....50,000 RPM

[greenman407]

Stuff ordered.

[greenman407]

Yep its a ducted fan unit, of the brushless variety. 64mm, 10 blade 3300kv and all metal. It runs on 4s power. The website I am going to get it from is:http://www.rc-electric-jets.com/

[greenman407]

What if we jammed one of these in there...............just for the heck of it? Why do we need more thrust? Because, this boat does not have a flat bottom like most airboats. It is a tunnel or Catamaran as some boats are known. It therefore has a lot of drag when its on grass. All the weight of the boat is "point loaded" on to the ground on two points, whereas a flat bottom would distribute the weight over a large area, thus reducing ground pressure and drag. Conversely, when its on the water it has less drag than a flat bottom boat because the tunnel shape of the bottom of the hull will allow air under it and lift the boat up.