FT article inspired Foamboard Air Boat on SNow

[nerdnic]

Where is your COG on these boats? They look great by the way. I have a 3s 1000mAh battery all the way to the rear under the top deck now on one side. On the other side I have a large bolt (about 4" x 1/2") to balance right to left as well as to keep the COG 30% from the rear. Today I was running it and a crash relocated the bolt and the boat handling changed quite a bit.If I put my battery where your's is located the COG would be very much more forward.
LooseBruce

I'm using a slightly bigger motor, a 2200 3s, and my motor stand is a smidge further back than the plans specify. This allows them to balance right under the motor. I added rocks as weights to the back but it was too squirmy.

 

[kabturek]

Here is mine:



added led lights:

and a video (night shots are out of focus and shaky but you get the idea ;-)

I'm now using a Turnigy d2826 swinging a 7x5 prop and its a blast.

 

[LooseBruce]

Here is mine:

View attachment 39672

added led lights:
View attachment 39673
and a video (night shots are out of focus and shaky but you get the idea ;-)

I'm now using a Turnigy d2826 swinging a 7x5 prop and its a blast.

Boy that looks great with the lights. I have to get mine back in action. I had to steal the motor for my Bloody Baron!
LooseBruce

 

[kabturek]

Boy that looks great with the lights. I have to get mine back in action. I had to steal the motor for my Bloody Baron!
LooseBruce

yeah the light are great - they light up the snow around



Damn i wish i hadn't knew about the Bloody Baron... i printed the bloody wonder plans yesterday and now im not sure what to build

 

[Craftydan]

Damn i wish i hadn't knew about the Bloody Baron... i printed the bloody wonder plans yesterday and now im not sure what to build

Foam board and servos are cheap -- build 'em both

. . . and don't forget the lights

 

[LooseBruce]

yeah the light are great - they light up the snow around

View attachment 39816

Damn i wish i hadn't knew about the Bloody Baron... i printed the bloody wonder plans yesterday and now im not sure what to build

I flew mine for the second time a couple of days ago. The COG should be about 2.75 back from the leading edge according to Sponz. This is a departure from the plans. I really like it. I am using the 24 gram motor and it slows down enough so even I can fly it easily and there is a lot more power available.I am not sure if the COG is exactly right on mine yet. The pitch is still a little twitchy but I am very happy with it.

I made mine so that I can swap the pod to the Bloody Wonder MKIII by plugging in only one servo lead.I am very pleased with both of these planes. easy to build too.

I have one more other motor left over which I think I will put in the air boat. It is an EMax CF2805. It only runs 2S and a 5-6" prop but who knows. I am sure it will still move!
Good Luck,
LooseBruce

 

[eagle4]

wow guys! these builds of my airboat are looking amazing. I am loving all the little mods everyone is doing to make it suit their needs. i especailly like the lights and putting the fpv camera up on the motor mount. great visibility from up there. It's really awesome to see you guys getting so much fun out of this Now I know how Josh feels when we build his planes

 

[SteveRobey]

Where's the boat?

We all keep calling this an air boat but I have yet to see one on water. I live in a city that is literally surrounded by a large, somwhat U-shaped lake, so there's plenty of water and as such I'm planning a couple of airboats. The first one is going to be an HK Swamp Dawg and I'm planning to scratch build another to keep up with it. Anyway right now I'm looking at everyone's designs to get ideas.

I realize nobody has replied to this thread in an unfortunate amount of time, so I'll be the guy to brush some dust off of it and ask, has anybody made this seaworthy in the last few years?

 

[PsyBorg]

My guess would be that water resistant foam was not around back then so putting them on water was not the best thing to try. I would take a guess that if these plans were used using the motor placement changes and the in hull battery that it could do well on water if sealed and properly painted / covered..

I am getting the bug to finish the one I started last winter late and may get it up for this winters project.

 

[SteveRobey]

My guess would be that water resistant foam was not around back then so putting them on water was not the best thing to try. I would take a guess that if these plans were used using the motor placement changes and the in hull battery that it could do well on water if sealed and properly painted / covered..

I am getting the bug to finish the one I started last winter late and may get it up for this winters project.

Psyborg: if you do re-visit this project I's like to share some ideas if you're interested. I'm going to make my best effort to design an air boat that will hopefully look and behave at least similarly to a real one. I'm planning to design it around an Emax MT1806 (Power pack A) and a 6x3 prop to start, though I may move it to a 5x4x3 depending on it's behavior. Safe to say if everything is designed to accomodate a 6x3, the 5x4x3 or similar will also fit.

Currently I've got it in my head that I can use standard white foam board for the build and just minwax the heck out of it to ensure it is waterproof. Put on a coat, let it set, sand it, add another coat etc. I have seen a few forum threads here and there where this has been done with good results so that's my plan currently. It does seem to be relatively impossible to find a good set of dimensions for an actual airboat hull, or an RC airboat hull that.. Looks right? There's a certain look the real ones have and it's somewhat in contrast to the scratch built RC airboats or powered sleds people have built to run on snow. I probably won't build a prop shroud for my initial attempts, but I might make a sort of arched duct around the propeller. Will see how that goes when I actually start putting something together.

Is yours modeled after this community design or are you going for something a little different like I am? I'm going to do my best to rapid prototype something and do what I can to keep it looking as "Traditional" as possible while remembering that physics is still a thing and at the end of the day it not only has to float, but it has to handle well and come up on plane properly or I will kill it and start over. I just wish I could find some blueprints or any kind of graphical representations that I could scale down to make use of. There seems to be a ratio but I haven't gathered enough information to determine what it is. Seems to be that the width of the transom is just slightly wider than the propeller and the distance from the transom to the tip of the bow at least appears to be about twice that length. Dept, if I had to guess is about 5% the width of the transom. Lastly, what about the angles? The sides, I would guess slope outward around 15 to 20 degrees and the bow around 20 to 30 degrees? These are all guesses I've made from looking at a couple hundred images, designs that annoyingly lack dimensions, sketches etc that I have found on the internet in the last 72 hours. So with that, more research is still required on my end.

I'll be starting assembly of an HK Swamp Dawg in about a week once all of the parts arrive and I'm planning to take a serious look at the dimensions on that boat and look at how it actually handles on water.

If you would like to share some ideas, I can PM you my email, or we can just continue to do so publicly on the air boat thread I created yesterday. That might be helpful to others.