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I hear you but, I would not know what to recommend for motor, ESC or props. It's a whole different ball game.
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Nortavlag Bulc -
Go surface drive or don't bother..
How fast do you plan on going in 24" waves?
You run time expectations are a bit unrealistic unless you have deep pockets for lots of LiPos.Grand River Marine Modellers
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You are going to have fun setting up your hull to run in both 24" waves with wind and flat calm lake water at the speeds you desire. Personally, I would not even try to attempt that with one hull and the same components, but I wish you the best of luck.
DouggieComment
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Really???
Do you advise the people who like old shovel nose hydros their boats are redundant?
I was asking WHY surface drives are better. Do you know?
Not fast at all, say like a jet ski, wave jumping, maybe 10-15MPH
OK, well guess that's where the learning comes in. Any educated guess as to what 2 8cell packs of 5000Mah driving the 5692 motor and a mostly buried 3 blade prop might actually give for run time?Comment
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Member revoltrunner was able to explain in a PM how the greatly increased amp draw of a mostly submerged prop might cause overheating issues in the motor or ESC. That's the kind of answer that makes sense. So now I believe.
I'm kind of taken with the look of the twin rudders, so I may just put a stinger in the middle, and cut down the rudders to minimum depth. (as deep as the prop tip?)Comment
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OK, so you got the answer on surface/submerged drives.
Are these the conditions you are expecting?
Need to know the KV of the motor, prop etc to give a somewhat accurate estimate of run time..If you have around 10000mah to draw from, with a 55mph (ish) speed, figure 5-6 minutes with a decent amount left in the LiPos so the don't get drained to much (20% left over)Grand River Marine Modellers
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It sounds like you want to look into OMRA racing setups, OMRA is a race series we have here in the UK that has a mix of oval racing on flat lakes lakes, often fairly choppy harbours, and proper offshore runs done in the sea with a full size chase boat which can be very rough indeed.
OMRA have several different classes some of which are about the same size as yours, but as runtimes are 30-45 minutes they are all IC and cant self-right, but I was doing similar with an electric I would look at adding a flood chamber to make it self-right.
They started off all submerged drive but most are surface drive now, those that are still submerged drive all have the prop under the hull near the CoG, so the hull acts as a huge cavitation plate, and any lift acts evenly on the boat. The rudder is also under the boat just behind the prop to get the best turning ability, which is one of the advantages of a submerged drive setup.
The main advantage of Surface drive are that there is much less drag from the driveline as it is normally out of the water. an increasing amount of full size commercial displacement boats are being fitted with surface drives.Last edited by NativePaul; 10-27-2015, 08:24 PM.Paul Upton-Taylor, Greased Weasel Racing.Comment
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Yes, that is it exactly.
I am often in areas that rough, normally at the east (windy) end of lake Ontario in Kingston. (That video looks like Frenchman's Bay in Pickering)
I live in Brantford, sail a full sized sail boat out of 50 Point, and am often down to lake Erie. All the bodies of water in between are fair game too.
Right again, I should have mentioned the Kv of the motor I am considering is the 730Kv (3Y) version. Still getting used to the electric nomenclature. The props I will be using will likely be in the 75-95mm pitch range, and only the medium lift styles.Last edited by ITOYMWYA; 10-28-2015, 02:15 PM.Comment
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NativePaul:
That seems to be the likely conditions and speeds that I will begin with. Interesting they gradually migrated to surface, the driveline drag issue also explains a lot.
The prop and rudder being underneath and near to the center sounds a bit wonky, but the reasons seem to explain it.
With the wildly varying loaded depth of a commercial vessel, does the driveline raise and lower so as to always be at the surface?.....interesting.Comment
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Check this out. Same hull as yours with the Castle setup in it.
He toasted the esc partly because he ran only 1 set of 8S packs instead of 2 8S packs in parallel. Good read and he may post pictures of his hardware soon I hope.
http://forums.offshoreelectrics.com/...sc-motor-combo Nortavlag Bulc Comment
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It might be worth a PM to Gromov, he races FSR-E which are FE submerged drive boats running for 15 minutes. They are very different boats to yours but he may have as good or better incite into what you are trying to do than most.Paul Upton-Taylor, Greased Weasel Racing.Comment
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