3foot 2" boat can't keep motors

[ReddyWatts]

This is not a conventional boat setup, just trying to help you get it working with the equipment you already have and least expense.

Your pb batt has 17 milliohms resistance. It will not work with your 3600kv motors. Program says it will over heat the motor with any prop large enough to push your hull.

It will work with a water cooled Feigao 14XL motor, 1200KV with your x457mm prop and a 80 amp esc for mid 20's speed 10 minute run time. It will use about 60 amps at 650 watts. It work better with an X648 prop using 40 amps 430 watts (15 minute run time) and more speed using your 60 amp esc.

http://www.offshoreelectrics.com/pro...-540XL&cat=116

http://www.offshoreelectrics.com/pro...od=ose-mjacket

[gmartin]

Still can't keep motor's can any one help me. Feigao 540 went out.

[ED66677]

just a question... another one! is the prop fully submerged?

[vvviivvv]

bigger motor bigger controller possibly bigger battery's? whats the budget?

[ED66677]

everything bigger would work... as long as it is used properly, but look at the very first picture, it seems to me the rudder is against the transom so the prop must be fully submerged, even a 540XL with a 100A ESC would burn in these condition unless he uses a very small prop!

[gmartin]

Yes ti is

[gmartin]

@ this point any thing go's I just want it to work water cooling helps but still not working for more then 8 run's @ 10-15min

[ED66677]

so the hull is around 30" long, you need a 540 8XL under 4S Lipo with a 80A ESC (min) a good start for a surface piercing prop would be a 42mm, you have to rework the drive line, fully submerged prop i s not the way to go!!!

[ED66677]

sorry my bad 3'2" long I missunderstood!

[vvviivvv]

i misunderstood too but a 8xl is probs too many rpm im getting 60mph out of a 8xl on 4s with a x642

[ED66677]

You're right vvviivvv, 8XL under 4S might be too small but if the hull is light why not, I've done it successfully on a 36" ABS hull with the same setup

A 580 will do it for sure as long as he choose a KV so that the prop spins around 13-15000rpm maybe less than that but way below what we normally use with surface piercing prop!!!

[Flying Scotsman]

@ this point any thing go's I just want it to work water cooling helps but still not working for more then 8 run's @ 10-15min

Please state your goals

Run time=

Speed=

How much do you want to spend=

You have a large boat and you have to decide what your piority is as you can not have high speed and very long run times. Depending on what your goals are, you are probably looking at all new components. Also how many runs do you complete at each session?

Douggie

[Ctonez]

If you are still running longer than 10 min, your probably running too long for an over-propped motor with minimal cooling.
What specific size is the Fiegao you burned?
540XL 540L?
8XL, 14XL?
Still using that HUGE prop? 8XL should have a 42mm prop.

The route you are taking (essentially trial and error) is an expensive one. I don't know much about Pb batteries, but I'm thinking that might be the component that is holding you back the most. The internal resistance that Reddywatts mentioned causes extra heat on top of the over-propping/overweight issues. Fiegao motors don't like that. Actually no motors like that, but Fiegaos specifically tend to heat up alot when pushed IME.
I like the 580L suggestion. That's probably what I'd do.

Are you covering the top at all when you run? Are any of the electronics getting soaked when you run?

Show up at a local race and the guys there (myself included) will show you how to get your hull moving at the speed you desire. That would also give you the opportunity to see how FE boats are typically setup.

http://psfastelectrics5.tripod.com/race_schedule2004.htm

[gmartin]

can any one tell me @13v & with a oct-450/3 &150amp esc what speed and amps this is a slower motor but at this time run time is what i'm looking for.

Weight: 730grams
- Speed constant: 230KV
- Shaft diameter: 10.0mm
- Max. efficiency current: 90A
- Working voltage: 13~37V
- Power: 2865W/60s
- Idle Current: 1.5A
- Prop: 20 x 10 /20 x 13 /22 x 8

[gmartin]

If you are still running longer than 10 min, your probably running too long for an over-propped motor with minimal cooling.
What specific size is the Fiegao you burned?
540XL 540L?
8XL, 14XL?
Still using that HUGE prop? 8XL should have a 42mm prop.

The route you are taking (essentially trial and error) is an expensive one. I don't know much about Pb batteries, but I'm thinking that might be the component that is holding you back the most. The internal resistance that Reddywatts mentioned causes extra heat on top of the over-propping/overweight issues. Fiegao motors don't like that. Actually no motors like that, but Fiegaos specifically tend to heat up alot when pushed IME.
I like the 580L suggestion. That's probably what I'd do.

Are you covering the top at all when you run? Are any of the electronics getting soaked when you run?

Show up at a local race and the guys there (myself included) will show you how to get your hull moving at the speed you desire. That would also give you the opportunity to see how FE boats are typically setup.
http://psfastelectrics5.tripod.com/r...hedule2004.htm

No open hull no water inside