raiki

Now this may sound like a silly idea but have a read and let me know what you think.

I have a spare Viojett ducted fan unit with a KBV82 motor and have been wondering what to do with it (I have two others for jets). I thought about a scale 1/8 turbine powered hyro but use a ducted fan to power it. (Maybe a little smaller).

I would think that if it got up on plane then it would get really fast and possibly even become a ground effect vehicle. BUT will it ever get up on plane.

Any comments would be appreciated. This will have no marine prop, all propulsion will be ducted fan.

nitorbtr

It most likely would never get up on plane If it was in a turbine style hull without the fan mounted on top like an air boat. Turbine powered hydros don't run on air thrust they turn a prop just like any other boat. It would be very cool to mount the fan unit on top of a cat style hull. they seem to handle air power very well. Good luck.

raiki

What sort of cat hull would you use?? How about a tunnel hull?? Point me to some plans or even some pics of the type of hull you are refering too.

I realise the full size turbine powered hydros use a turbo shaft like a turbine chopper but I was hoping my hydro would float about an inch ABOVE the water so a stardard marine prop just wouldn't cut it.

How about a hydro foil type boat, now that would be fast (Assuming it ever got fast enough to get up on the foils.

Saugling

What will happen if the boat rolls over and the DF gets water??? Total DF / engine destruction???

raiki

No big deal. Thats the risk we take with models isn't it?

75Blazer

It's just a matter of thrust vs. weight. If you have enough thrust you can make just about anything move as fast as you want it to. Of course there are structural limitations that you'd need to consider, but we're not talking about trying to mount a turbine from a 747 onto a surfboard. I say give it a shot and let us know how it works.

What about a hull like this one?

http://www.rcuniverse.com/attachment...&postid=726873

Saugling

....hmm, there seem to be some people with to much money :surprised

raiki

I by no way have too much money, I am just realistic. (and if you ask my wife my priorities are all wrong)

snwskaiz, I like that hull but I would prefer to do a hydro because I THINK that once on plane there is less water resistance in a hydro.

I am currently building an Electric 1/12 size (but not scale) hydro (150% hydromite) from a plan. I might just scale that plan up a little and try the viojett. (Unless someone comes on board saying they have tried it and it doesnt work).

Right now I dont know how big to make the DF hydro.

Flying Monkey

Hey Raiki! nice to finally find someone from my own city! I reckon your ducted fan found work well of you got the right hull. Think about it: what is an airboat? many airboats do upwards of 35mph.

what i really would love to see is an AMT 20lb-thrust turbine on a boat! now that, would definately heat up the water (but if it rolled, you could say goodbye to A$5000!)

Cactus.

My Feedback: (1)

DF dosnt have static thrust, thats why the planes take off like lead hairdryers. airboats have plane props with give loads of static thrust and get them moving, i've seen a DF on a hydroplane style hull and it went nowhere, a airboat design might have more luck, but you wont go fast enough to get into dynamic thrust and get it working

canadianjosh

in my opinion it woulod be a neat thing to do but would be a waste of money, unless of course you are talking about mounting a turbine engine, then we're talking. Ducted fans are just a ****load of low pitch blades on a hub that gets spun really really fast. You have to think about some things here, why invest money in a ducted fan when it is going to be more maintainence, weigh more(engine, fan housing, all the gear) when you can have a simple prop creat the same amount of thrust??

RC-Archer

If you've already got the Ducted Fan, Go for it!!

As for testing, just get some blue foam and carve it into a boat shape and mount your Duct fan to it and see how it works. Play with the CG a little and see what happens.

I think it would be cool to build a Batmobile type Hydroplane and power it with a ducted fan.

raiki

Well I do have a Viojett and KBV82 sitting here doing nothing so I dont need to spend any money.

If anyone wants to donate some 1/8 scale hydro plans (batmobile would be good too) I'd be quite happy to experiment.

If it doesn't work no big deal, at least I had fun and thats what I thought all you people wanted from this 'sport' too.

Oh and as for the no static thrust, 12lbs is hardly none ????

Come on guys, get in the spirit of experimenting. Sounds like no-one has actually tried this but you all say it wont work. I think people told Orville and Wilbur that too !!!!

Cactus.

My Feedback: (1)

i have seen a 0S46DF on a hydro hull, and it was as fast as my tyco yacht, i kidd you not. he never ran it again.
if these DF's have that much static thrust how come they take off like hairdryers? im talking OS46 in a hawk, when the prop version would do it in half the length.
i did hear before that this was tried with a turbine, with the same results.
not saying it cant be done, just what i've seen so far

75Blazer

Here's a set of plans. I'm sure you could make adjustments to make it any size you want.

http://www.rumrunnerracing.com/plans/hydromite.htm

raiki

Phillybaby, the VioJett with an 82 will have considerably more thrust than the 46 and I assume a Turbax for only a little extra weight.

I think I agree with you but there is no harm in trying. If neccessary I will launch it from my ski boat (14'6") so it will be on plane from the start. I just want to see how fast I can make a boat go.

snwskaiz, I have those plans and nearly have the 150% hull complete ready for hardware. This will be electric powered.