Customized setup for airboat hull (electric)
 

Hello.
I have a 60" long Fiberglass airboat hull that weight about 20 lb, I am looking for the right motor, prop & battery setup for it (must be electric), can anyone please advise?

Thanks

Wow...umm. OK. I'm not real versed in electric set ups, I have a few cheaper set ups and one that I just recently used to turn a 3 point hydro into toothpicks @ 65mph.

Here it is:
Motor: https://www.hobbyking.com/hobbyking/...dproduct=23176
Batteries: http://www.hobbyking.com/hobbyking/s...arehouse_.html

I use a combination of two 5 cell and one 4 cell to get to my voltage which is overvolting that motor.

The ESC I use is water cooled and $300. Not sure if you want either if those features. LOL. I would suggest an air cooled high voltage, high amperage, but I would waterproof it as soon as I got it and tested it.

Here are a couple that might work. The reason I say might, is, my amp meter only goes to 100a so I've never fully tested my set up. WAY over 100a though, so I'd err on the big side.

http://www.hobbyking.com/hobbyking/s...hless_ESC.html
http://www.hobbyking.com/hobbyking/s...arehouse_.html


Want to see a video of it? I got my You Tube channel linked in my signature right below.

Thanks Crispyspa
How long would you say it can run with this setup and what speed could it get?

If you're easy on the throttle and use an 18x8 or a 20x8 two blade prop, (If you can find a non wood one) you'd probably get 10 minutes out of it. speed? You may get 25 mph before it would want to blow over.

On mine with a 16x10 prop at mostly full throttle I would get 4-5 minutes. Boats are power hungry.

What about a massive deep cycle battery such as:

http://www.amazon.com/Odyssey-34M-PC...n%3A7019843011

and this motor (If needed - twin motor of this type):
http://www.hobbyking.com/hobbyking/store/__17987__Turnigy_RotoMax_50cc_Size_Brushless_Outru nner_Motor.html

would it do the job for above an hour at 80% speed?

There you go, now you're thinking. Power is power. The motor doesn't care where it comes from. That motor is a beast. That'll get it moving, but you'll need 3 of those batteries to get it's full potential because at 172 kv, it will only spin around 2000 rpm @ 12v.

mmmm... I need to conceder weight also, if i add 3 batteries and run with the full potential RPM I will lose speed due to heavy weight, I can squeeze 2 of these Marine batteries but I think 3 is too much for my 60" long hull...
Isn't there a way to get the full potential for this motor with 1 or 2 of these Marine batteries?

The link to the motor is no longer valid, this is the updated link:
http://www.hobbyking.com/hobbyking/s...ner_Motor.html

I think you should consider other battery technology, personally. Those group 24 deep cycle batteries weigh in excess of 75lbs usually. You would almost need a canoe or small rowboat to handle the weight of the batteries. I hate to be a Debbie downer, but I don't see this setup being economical in the least. It would work, but at what cost? Two batteries at $334 each plus the other stuff? The whole setup may end up costing $1k or more. :O

Money is not an issue here, I must make it work, i will learn from this model and the next one will be way more efficient but i need to make a boat runs at ~20 mph for at list 2 hours without charging it, my hull is a flat end fiberglass airboat hull, about 60" long, Is'nt that enough for carry all the batteries and stuff?

Then what I suggest is take your airboat hull you have and put 150 pounds of weight on it and see if it will still float. That's the first hurdle. The next hurdle will be if your power system can drive the boat at that weight at 2 hours at 20mph.

Crispy - don't you think using a whole pile of LiPo battery packs wired in parallel would weigh less and be more efficient than using deep cycle batteries?

I just don't see lead acid batteries being the right choice given the hull size and performance requirements.

Are you asking the same question but in another posts?

http://www.rcuniverse.com/forum/rc-a...ease-help.html

I am not the smartest guy on the planet but If a regular personal airboat is about 90" long and it can carry a diesel engine and an actual human being then i don’t see any issues with 60" long carrying few batteries and brushless motor.......
please correct me if my assumption is wrong.

BTW - the motor i refered to is equivalent to a 50cc gas motor

I/we are just trying to help give you the best advice. My thought is that a fiberglass hull 5 feet long (unknown width and depth) likely will not move at your required speed carrying the weight of the equipment you'd like to use. At least IMO. You have to realize that you (if using two deep cycle marine batteries plus motor and electronics) are going to need enough thrust to make roughly 150-200 pounds move at 20mph for 2 hours. I just don't think you will have success with this idea.

It may produce the horsepower and thrust of a 50cc engine, but this is really moot because the motor is designed to propel a model in the 20-40lb range.

Maybe im off base here, but I don't see this idea working without considering a lighter weight power system (ie: batteries).

I see what you mean… I know it is problematic but I still need to come up with solution, the only advantage I got here is that money is not an issue, I can go up to 1k$ easy, even more if necessary.
If a new hull need to be made - I will make it (Not me, the factory), same goes for motor and batteries setup.
The only thing i cannot compromise about is the ~2 hours run time in ~20 MPH.

Someone advised me to use electric motorcycle engine, not sure about it… I still believe that the engine I mentioned above will do the work, just need to give it enough power.

Did you do some homework and check out a forum dedicated to electric motorcycles?

I think you should be looking at using a weedless wet propellor instead of air screw propellor. Will be much easier to move with less wasted thrust.

asmithnc - to your comment: yes, I posted on another thread about me looking for plans to buy, I got the plans (Flat & Hydro) and already sent them for manufacturing. best 150$ I ever spent.
Now i left with the engine & power source, I made some good progress at the past few weeks.

About the Motorcycle engine - It doesn’t matter what engine i take, a battery is a battery no matter how you look at it so basically I'm back to square one..

About Weedless propeller - does "weedless" means i won’t get weed stuck inside the propeller? because this is why I chose the airboat model to begin with...

I say weedless wet prop because they are more efficient in making forward motion. I mentioned it because the weight of your boat will be high and will require substantially more thrust just to make the thing move. An easy comparison is driving your car on ice versus dry pavement. More slippage on ice (air screw) than dry pavement (water screw / wet prop).

Sounds right, but the reason i chose to go with Airboat is because I am too scared of weed get stuck inside the propeller, the water vessel will remains 24/7 inside a fish pond...
I need as less human Interference as possible, low maintenances & high reliability, thats why I chose airboat.
Did i made the right Decision?

He could adjust the size of the hull to hold the lead acid batteries. I think lead acid is the way to go on a project such as this. Easy to charge and far less fickle than a whole slew of Lipos would be. Lipos might be lighter, but not by much as many would be needed to get the run time.

Any reason it has to go 20 mph? Won't a slow moving vessel scare the birds just as effectively as a fast one? We are talking about scaring waterfowl off the pond, right? Have you considered a bird cannon? https://www.youtube.com/watch?v=3_YPpcCQZGY

Cannons doesn’t work, some birds get used to the cannons sound after 2 weeks, I had these installed in my pond and I was happy for 2 weeks… after 2 weeks I saw a cormorant seat on the cannon while it made the explosion sound, completely ignoring it... after 2 weeks the entire flock came down seating on/next to the cannon - it is a very smart animal…
Anyway, the pond is about 32 acres and I got 3 of these ponds… it means I have about 1,640 FT from one end to the other, less than 20 MPH would be too slow and by the time I get to the Pelican/Cormorant flock the damage is already done.

I still think for power source an electric motorcycle engine geared will give you the best option. The forum will help you piece together a battery/electronics package. The fact it is for an airboat doesn't matter. Sounds like you need bursts of speed to keep the flock out. This is do-able but you need to think outside the box. You can always spend a lot of money and just cover your pond with plastic balls?

Plastic balls are static, the cormorant is smart....
Electric motorcycle engine is not designed for water and i will probably have to adjust it a lot for my purposes, it is possible but a lot of effort.
What about 3 of these motors installed on a flat bairboat hull?
http://www.hobbyking.com/hobbyking/s...Motor_Set.html