Unlimited Hydroplane Size does matter

[podagee]

Hi there people this is my first thread on this OSE. So i raced boats before in the 1980's and always wanted a Hydroplane. So i'm starting again, and i'm making 2 1/8 scale hydroplane boats. I've started on the Atlas and Pay N Pak. My question to all is that is there anybody with a 1/5 scale Hydroplane Brushless Electric boat. I've seen boats that is 1/5 scale but not electric and can a T5692 Turnigy Pro Comp Brushless Inrunner Motor 780kv do the job. and what size prop would I use. I wanted to use a 3 blade prop if that would help. I've attached 2 pictures of this two guys with 1/5 scale hydro boats. I'm Starting that build as soon as the Plywood from national comes in.
Budxs2.jpg Bud7.jpg

[Diegoboy]

Welcome to OSE!
That is HUGE, I assume it's going to need a huge motor too. What number of cells will you use? I think a 56mm motor may not be enough, maybe an outrunner?
THIS is the biggest motor I've seen but the KV is too low

[LarrysDrifter]

Is there a gear box out there that would allow the use of 2 motors and use a single driveline? If so, would it make sense to use it?

[egneg]

There is the Neu 4400 series that may work but it's limited to 10,000 rpm.

http://www.neumotors.com/Site/4400_series.html

[Doby]

As the 1/8ths you are building are you first Hydroplanes, and you mentioned that you raced boats in the 80's....then start here...
http://www.offshoreelectrics.com/pro...less+Hydro+RTR

[Brushless55]

Those Hydros are awesome!
maybe the 530kv version on 15s could work?

[podagee]

goboy: they got higher kv 1000,1320 motors you think it would work. Well for the cells I was going to start with 12s and see if that should be good. Does the outrunner motor go bigger than 5692? Drifter If I use two motors then i would have to use 4 batt packs right, I would like to stay with one motor. if you know of a place that has a bigger motor at a high rpm i think that would work. 10,000 rpm is to low. even if you where to gear it up.

[podagee]

neg: I just looked at the Neu motors and I think I found it. The 2220 24 series has 430kv 30000 RPM 3000 watts continuous and 6000 surge watts at 70 Volts Max. The case size is 2.45" i can fit that in side. I'll try the 12s batt if that don't work then ill go higher. When i start my build i'll post it in the OSE build.

[Doby]

Remember...higher voltages can lead to death..

[egneg]

Remember...higher voltages can lead to death..

Yours?

[JIM MARCUM]

WOW!!! That's one huge hydro.

Don't know if this will help, but I converted a 46" long Purple Light gas hydro to FE that worked well. I ran a Leopard 5692 730KV 8S2P (21,608 RPM) with the gasser stock prop. It hit 64 MPH on my GPS before I crashed it (totaled). Good thing the GPS was taped inside a pool noodle & was floating along the pieces of my boat.

Please share how that Mother of All Hydros project works out. JIM

[Punisher 67]

IMHO a Lehner 3080 for that boat would be bare minimum , I wouldn't even waste my time with a 5692 - Dual 3080's can motivate a 8 foot 70 pound cat to almost 100 mph

[podagee]

I'll post my Build and when that's done i'll post the test runs. The 3080's sounds good but I'm not sure of paying $745. for that motor.

[Punisher 67]

How fast do you want your boat to go podagee - I can appreciate the fact that you want to stay within a reasonable budget but motivating something that large is going to take some serious horsepower and possibly some $$$$$$$ coin also . The 44XX series Neu mentioned above is another $250.00 more than the Lehner . There are a few outrunners with some serious torque also - Little screamers and the scorpions which are in around the $200+ range but this also will take at least two motors minimum as to not tax the single motor to much . Hydro's are not my specialty - mono's are more my cup of tea - from 45 - 60 inch and I can attest to what bare minimum would be to run these hulls at any appreciable speeds . A 5692 is a great motor for a budget 45" - 55" build but its way out of its league in a hydro that large .

I am hoping a few hydro boys chime in here to maybe pin down whats appropriate for your build .

I tip my hat to you thats one hell of a coool project you are stepping into............

[Fluid]

Huge boats look cool and many of us drool over them - but then of course we will never build one. Why would we actually want one? No racing class, no FE insurance, costs what 3 smaller boats would cost, difficult to run single-handed, needs a truck or trailer to transport, and after the first couple runs up and down the pond all that's left to do is to bathe in the adulation of a few on-lookers. To each his own though, and I applaud someone trying to do this. But...

While I have not built boats larger than 10S or 45" personally, I can't see how this build can be done on what most would consider a "budget" - not if speed, reliability and fun are important to the OP. Power requirements increase approximately by the square, so if a 40" boat requires minimum of 3500 watts to perform decently (and more than 4000 watts to really shine), then a boat approaching 80" will need ~7000 watts for similar performance. AFAIF no single motor/ESC combo has proven to be able to supply that level of power with run time and reliability. Certainly not outrunners, which by design are low-amp motors. The Neu 2230 motors don't come close to the continuous power requirement and are limited to 12S. The LMT 3080 would be heavily taxed as well. As for ESCs - reliability at this power level is problematic. Cheap Chinese LiPo packs will not last at this power level. I can't see a prop less than 75mm in diameter working well on this boat, that's a lot of prop.

A lot will depend on what the OP will settle for. If he is content with speeds in the 40s then perhaps a single motor will suffice, although getting the boat on plane could be an issue with a reduced-power system. The OP needs to build his 1/8th scale boats first, then he can decide if a 1/5th scale is practical for him (does he have a PU truck to haul it with?).



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