Dr Super-Evil (Hydro 2) tuning

[Ivan Kozyakov]

As Paul pointed out, if you looking to go fast, sponsons with less areo lift may be desired.
You can make your own that are narrower than the current design, or contact Cedric Lefebvre on the FB group Rc Offshore Saw. He sold a twin kit of that same tub with different sponsons.

https://www.facebook.com/groups/1937681899859203

Yes, I am planning new sponsons and will make them myself. But if you have a photo or an example drawing I will be grateful.

[Ivan Kozyakov]

I gained a lot of speed from mine by raising the strut (flat on a setup board with the top of the strut about 3mm below the tub) and increasing the AoA on the sponsons (not sure how high an angle, but I had to mod the boom extensions to get it high enough. I also have a ski now, but that was not a huge difference like the strut and AoA was.

NativePaul, if I understood you correctly, did you lift the strut higher (not 13mm as in H&M the photo, but 10mm)?Krabs_Tech_002.jpg

I have now set the angle of the sponsons to 1.5? and I am already afraid that the boat will take off like an airplane . Do you recommend a larger angle?

[NativePaul]

That mr Krabs does look like about where I have it on my dr super evil. For 100kph for sure you want a lot more than 1.5 degrees of AoA, I'm pretty sure mine has over 6. My SAWs boats have 3, but these are not the sponsons you want for SAWs.

I was getting very inconsistent performance and found that my strut was moving slightly in use, the teardrop strut suffers from a small contact patch against the "bracket" gluing a sheet of emery paper back to back, and putting it between the strut and bracket fixed that.

[Ivan Kozyakov]

Guys, please explain where the СG should be located in his Hydro-2 boat? I am targeting 25% between floats and propeller but is this correct?

[Ivan Kozyakov]

Guys, please explain where the СG should be located in his Hydro-2 boat? I am targeting 25% between floats and propeller but is this correct?

If someone interested in this question i have the answer from Hydro&Marine about CG:

Zuschneiden.jpg

[Ivan Kozyakov]

Can someone please explain the difference between a bent, rounded and straight turnfins?

[Ivan Kozyakov]

Hi guys!


I made some adjustments to the СG and sponsons and ran a series of tests on the new propellers:

- 45mm/1.4 Tenshock prop - very slow
- 46/1.9 ABC copy - 129 kmh
- 48/1.9 ABC copy - 134 kmh

The motor 4082 2000Kv SSS is warm, looks like I can load it more.

But 180A Seaking ESC hot very fast on 46mm and 48mm prop. Impossible to hold by hand. Cooling works well, I always see a fountain of water. Does it make sense to install a second cooling circuit or is this the limit for this ESC?
6s 100c battery pack.

[Fluid]

My guess - based on not actually seeing the OP?s setup - is that the ESC is at its limit. This is probably due to overloading the motor, his calculated rpm with the 48 mm prop is around 29,000 yet that motor is better suited for 35,000 to 40,000 rpm. The reasons for the low rpm/high amp draw include a low-efficiency motor (poor materials or magnets damaged by excessive heat), too much prop, boat running too wet, or excessive driveline drag. Alternately, inadequate batteries with high voltage drop (don?t believe claims of 100C), the wiring between the ESC and the batteries is too long/poor quality/poor connectors, or poor soldering. This stresses the ESC and will overheat it. If the OP cannot hold the ESC in his hand it is probably not long for this world if he doesn?t reduce the stress on it.




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[Ivan Kozyakov]

My guess - based on not actually seeing the OP?s setup - is that the ESC is at its limit. This is probably due to overloading the motor, his calculated rpm with the 48 mm prop is around 29,000 yet that motor is better suited for 35,000 to 40,000 rpm. The reasons for the low rpm/high amp draw include a low-efficiency motor (poor materials or magnets damaged by excessive heat), too much prop, boat running too wet, or excessive driveline drag. Alternately, inadequate batteries with high voltage drop (don?t believe claims of 100C), the wiring between the ESC and the batteries is too long/poor quality/poor connectors, or poor soldering. This stresses the ESC and will overheat it. If the OP cannot hold the ESC in his hand it is probably not long for this world if he doesn?t reduce the stress on it.
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If I understand you correctly, if I want to save current setup (6s, 2000Kv, 180A ESC) the only way is a smaller prop and lower speed?

And if I want to continue to increase speed, then I need a new ESC? As I said the motor feels good, warm.
I already looked at the Flier ESCs, but they are quite heavy (400g).

As you advised, I will check all the contacts and corners and etc. But this is a completely new boat (motor, esc, lipos), there should be no hidden defects.

This boat drives so well I want only increase my results