"ETTI" Rigger (Demon) building directions

[sailr]

Dee,
Great thread! Very informative! Thanks

[6S HYDRO]

yes, there is not a problem without mounting stuffing tube for supporting the telfon tubing and flex cable.
That .130 telfon is fitted for inserting into the cone of the our etti strut, no need to insert extra stuffing tube.
Without stuffing stub, it is easier to adjust the strut angle than having stuffing tube for running!

i understand it will ease adjustment, but i had a problem w/ my bj with the fullers hardware- it had about 3" of unsuported teflon and under high power applications it knotted the flexshaft in that portion. I have since placed 3" of tubing there and have not had a problem

[PhoenIX_rc]

Hi!

Very interesting photos.

Is the boat built for ovar racing, or just for fun?

Do You have issues with battery overheating?
What time did You get on etti motor? what diameter prop is that?

Best Regards
Robert

[KTM_EXC]

Hi there.
Just a quick question: where the CG should be in this model?
I am bulding a Demon and now I have to decide where the motor/ESC/Batteries shold be.
Thanks to everybody
Andrea

[Dee]

HI Robert,

This Hydro is designed for oval racing!

We can run this rigger around 6 mins from the following setup:
- 2S1P 5000mah 7.4V Lipo pack
- ETTI B29 4650kv Brushless motor (Water-cooled)
- ETTI 150A (24V) ESC with BEC (Water-cooled)
- ETTI 36mm CNC prop

This setup did not cause the battery overheating so far (of course , it's also depended on the building quality by the racers themselves...)


Best regards,
Dee ^_^

Hi!

Very interesting photos.

Is the boat built for ovar racing, or just for fun?

Do You have issues with battery overheating?
What time did You get on etti motor? what diameter prop is that?

Best Regards
Robert

[Dee]

Hi Andrea,

The CG of this rigger would be around 315mm to 330mm from the transom of the hull.
Basically, CG of the rigger is easy to be found!
It's should be located at the place of the mounted turn fin.

Hope this helps!


Best regards,
Dee ^_^

Hi there.
Just a quick question: where the CG should be in this model?
I am bulding a Demon and now I have to decide where the motor/ESC/Batteries shold be.
Thanks to everybody
Andrea

[KTM_EXC]

Demon

Dee,
thanks for your suggestion about CG;

One more question if I can. What about this set up:

- Neu Motor 1512 1D 4875 Kv
- ETTI 150A (24V) ESC with BEC
- 2S1P 5000mah 7.4V Lipo pack
- Octura X435 (or similar)
Do you think it can last six minutes or the motor is too much Amp greedy?


Thanks again for your help

Regards
Andrea

Hi Andrea,

The CG of this rigger would be around 315mm to 330mm from the transom of the hull.
Basically, CG of the rigger is easy to be found!
It's should be located at the place of the mounted turn fin.

Hope this helps!


Best regards,
Dee ^_^

[Ub Hauled]

The motor is amp hungry, any "D" wind for that matter... have you looked into the 1509/1.5D ?
Some guys are using this motor with a lot of success here in the US.

[Dee]

Andrea,

Owing to I do not know the idle current of this 1512 1D 4875 Kv motor, It is hard to tell you can it last 6 mins.....

The runtime is depended on the current drawn by the running motor, if it will draw a less current and it should be no problem!
Otherwise, .....you know!

Dee ^^

Dee,
thanks for your suggestion about CG;

One more question if I can. What about this set up:

- Neu Motor 1512 1D 4875 Kv
- ETTI 150A (24V) ESC with BEC
- 2S1P 5000mah 7.4V Lipo pack
- Octura X435 (or similar)
Do you think it can last six minutes or the motor is too much Amp greedy?


Thanks again for your help

Regards
Andrea

[Ub Hauled]

Andrea,

Owing to I do not know the idle current of this 1512 1D 4875 Kv motor, It is hard to tell you can it last 6 mins.....

The runtime is depended on the current drawn by the running motor, if it will draw a less current and it should be no problem!
Otherwise, .....you know!

Dee ^^

1512/1D
Io@10v = 6

1509/1.5D
Io@10v = 3.8

[KTM_EXC]

I was looking at that chart and wondering what Io@10v means
Can you help me?
Thx
Andrea

1512/1D
Io@10v = 6

1509/1.5D
Io@10v = 3.8

[PhoenIX_rc]

Hi!

This is idle current.

Motor runnig with no load at 10 volts is drawing 6 amperes.

So 10 volts times 6 amperes is 60 watts of wasted energy only to run the motor at idle.

[KTM_EXC]

OK
Understood
That means - roughly speaking - that this motor has more torque in respect to the other one that "waste" 38 Watt only when in idle state?

Hi!

This is idle current.

Motor runnig with no load at 10 volts is drawing 6 amperes.

So 10 volts times 6 amperes is 60 watts of wasted energy only to run the motor at idle.

[PhoenIX_rc]

Hmmm. there's no simple rule there.

This is combination of few factors.

Bigger motors usually do draw more current on idle, but I0 depends more on KV.

Motor with higher kv will have smaller internal resistance, less resistance will cause bigger amp draw when idling.

You also shouldn’t consider this I0 as wasted energy since this motor is optimized for high current application. Even if efficiency at idle and at low load is very poor, at motors typical power output the efficiency is far better.

And speaking about torque of brushless motor. The limiting factors are: how much power the battery can deliver, the second factor is motor internal resistance, ESC res. and wires connectors ( the lower the better for max torque) and finally the max power of magnets and iron core can handle ( i don't know english word for it)

And of course serious limit is time and heat dissipation abillity.

I hope somebody can understand anything of i wrote above :P

[Ub Hauled]

you are on "the money"... don't worry.