What Feigao for Toysport Triton ?

[G Doggett]

Thanks again Reddy.
That Y537/3 is a magic prop.
Seems like my plan to get 50mph from 18 of my cells with only 50 amps draw was a bit optimistic.
I will still use a 12XL but might have to settle for 40 - 45 mph top speed.
We race around the full circuit with 100 metre straights so by the time you have completed 1 coursing lap to the clock start, 4 racing laps, and then a slow down lap, you have used up pretty close to 3 minutes on the water.
I don't want to drain the NiMH cells down too far so my calculations are based on at least 5 minutes running.
Just have to start saving for those lipos and a Neu.
Graham.

[ReddyWatts]

Yes it takes the 3rd blade into account, the shorter blades help reduce amps. That is why this is my favorite prop. It is just a little small for some hulls. It has been the most effecient prop for my setups. More speed with less power for the kb and fiegao motors. Go back and read the speeds I added to the setups. The Y537/3 is close to the same speed as the X640 but using 20 amps less. I have tested it.

I am using the Y537/3 on a Mean Machine with a 77 amp HV controller for 2 years now with no problems I have purchased a X637 prop. Have not tested it yet..

[Ctonez]

FeCalc says;

12XL, 18 cells/21.6 volts, Y537/3 prop, 50 amps, 26060 rpm, 1000 watts.

Does the FECalc take the extra blade into account, or is it just reading that prop as a 37mm 2-blade? I get the impression the 3rd blade isn't being calculated, and I'm pretty sure a 3-blade causes more amp draw than a 2-blade of the same diameter...???
Am I confused or just confusing?

[ReddyWatts]

FeCalc says this for a mono hull;

12XL, 18 cells/21.6 volts, X640 prop, 70 amps, 24336rpm, 1300 watts. 43.5 mph

12XL, 18 cells/21.6 volts, X440 prop, 62 amps, 25559 rpm, 1200 watts. 39 mph

12XL, 18 cells/21.6 volts, X637 prop, 58 amps, 25552 rpm 1100 watts. 43 mph

12XL, 18 cells/21.6 volts, Y537/3 prop, 53 amps, 26060 rpm, 1000 watts. 42 mph

12XL, 18 cells/21.6 volts, X438 prop, 53 amps, 26034 rpm, 1000 watts. 38 mph

[G Doggett]

Cheers Reddy
Thats the sort of info I need.
That's 1400 watts, so as I only want 1000, by my rough guestimation a 12XL on 21.6 volts should draw about 50 amps also with a conservative prop.
Guess I'll just have to suck it and see.
I realise there is a lot of trial and error with this kind of thing but I want to start somewhere close to the mark if possible.
Graham.

[ReddyWatts]

I have run the 14XL at 50 amps on 28.8 volts using the Y537/3 prop in a 29 inch cat.

[Steven Vaccaro]

Thanks Steven.
So where are all these FE experts when you need them ????
Graham.

I kind of work it differently. I run the motor I think will get me in the general amp area than prop to the amps I need.

[G Doggett]

Thanks Steven.
So where are all these FE experts when you need them ????
Graham.

[Steven Vaccaro]

try the conversion on the bottom of this page.
http://www.offshoreelectrics.com/conversion.htm

It doesn't give amp readings. I haven't found a software program that would do that with good results. But it helps point me in the right direction.
I think to get to 50 you will need more than 50 amps.

[G Doggett]

OK I'll reword the question.
Guys who have run the Triton tell me it needs a prop of around 45 mm to push this large hull, and I want to go the high voltage/ low amp set up with 3 packs of 3800 cells to give me a total of 21.6 volts.
Which Feigao should I use to produce a 50 amp max draw 10XL, 11XL or 12XL ?
Graham.

[SJFE]

Thats ok Graham I just noticed you where refering to the triton....lol

[G Doggett]

Sorry - typo error ( clumsy fingers )
I have just corrected my last entry to read 18 cells.
Graham.

[SJFE]

I ran the 9xl K40 on 16 IB3600s and the dpr avaraged 65 to 75 amps. You may want to drop to an x638. Then again you can always cut the k40..just remember it changes the pitch a little.

[G Doggett]

Hi Steven
Thanks for the info.
What prop do you ( or the FE Calc ) recommend with the 10XL on 18 cells?
Keep in mind I am trying to keep the current around 50 amps to preserve my batteries.
Graham.

[Steven Vaccaro]

A 10xl will get you in the 40's and keep the amps down. A 9xl will get you into the higher 40's but the amps will be much higher.