fe motor ,speed control ,and batteries

[bob miller]

new with fe electrics , what would be the best motor ,speed control , and batteries for a 30 in aero marine sprint cat , weights in at 3 3/4 lb , .....i race impba ovals , usually 5 laps , sometimes 6 laps , club racing....i prefere to buy good equipment , not the cheap stuff.....thanks....bob

 

[James Schmidt]

Bob, I am building my first electric boat too. My boat will be 32" so it is considered P and P limited. The electronics that were suggested to me were 3630 to 3650 1500kv engine, ZTW 130 amp ESC, and 4s 75c batteries.
What I have read in namba and impba rule book about P And P limited is excepted voltage differences. Also in P class they allow any engine with voltage between 11.1 and 16.92
In p limited your engine can can not exceed 56mm in length and with out looking at the rules the diameter can't exceed 37mm.

Hull length for P and P limited are 27" to 34"

Im finding it hard to get 1500kv engines. I bought one of the last ones in stock over many websites. Of course Maybe I am not looking in the right places.

Every thing available is between 1700kv and 2000 kv. I am as new as you are to electrics so I am not sure if these KV's will work just going by what others told me

Jim

 

[johnmills]

Jim, P-hydro motor is usually around 2000Kv, a cat shouldn't be a lot less. If you were looking for 1500Kv and could only find 1700Kv you can drop down on the prop size to compensate for the increased RPMs.
TP Power sells direct if you can't find what you're looking for from a retailer.
I'm running a TP 4040 2100Kv in my P-hydro.
https://www.tppowerusa.com/motors/in-stock-regular-motors/tp-40xx-series-1

 

[James Schmidt]

Thanks John, so what I am understanding here it that the more kv in the same size motor has less toque or ability to load without getting to hot or stressing out the system. But it will have more RPMs with higher KV. right?

when you have to keep your voltage between 11.1 and 16.92 is it better to have smaller engine can and more RPMs and smaller prop, or bigger engine can, less kv and bigger prop without
Burning something down.

Trying to get an understand of electric. I have been a nitro burner in the hobby all my life.

Thanks Jim

 

[James Schmidt]

Also how do I know I have enough amp for ESC when going to bigger engine and more kv?

 

[johnmills]

Jim, I'm a nitro guy as well, so I'm no expert. Hopefully, someone more knowledgeable will correct any misstatements I make. Kv does not relate to torque in a general sense. Magnet strength/size, stator wind, etc., determine torque. You can have 2000Kv motors of vastly different torque; higher torque motors are, in most cases, longer/larger diameter. In the same size/mfg, the lower Kv motor will have more torque. Amp draw will depend on a number of things, voltage, prop size/pitch, hull type, and setup, among others. While most motor manufacturers list a max amp draw for their motors, and it's always rewarding to figure things out for yourself, it's so easy to burn up a motor or ESC that, to get started, it's best to get advice from someone with experience on a particular combination, hull, motor, ESC & prop. When you do ask for advice, give a complete description of what you have or intend to get and what you plan to do with the boat, you'll get much better information. If you haven't already, you should check out the Offshore Electrics site. A ton of information there to wade through if you've got the time. FWIW electric motors are usually not referred to as engines

 

[James Schmidt]

Oops! Sorry Bob I didn't mean to steel your thread, I think John helped us both.

Thanks for the help and the lead on where to get electric motors.

Jim

 

[J.J. Horvath]

Decent setup for P-Ltd: Dynamite 3831-2000kv (36mmx56.5mm), OSE/Flycolor 150A esc, ABC 1714 or M445 prop, good 4S lipo with 5000mah total

Full P: Any motor 36x75mm to 40x82mm (can be any size really so gave a size range) -2000kv to 2200kv, 180-220A esc, 4s lipo -5k to 6k mah.

These setups should get you in the ballpark to be competitive.

 

[bob miller]

thanks for the info ,what is a good source for fe equipment ?....bob

 

[J.J. Horvath]

Offshoreelectrics.com
Zippkits.com
Rattlesnakerc.com
Hobbyking.com (Turnigy HD/Panther Graphene lipo packs)

 

[andy fraser]

My p sport hydro 4092 2000k 180 hobbywing 2 3800mah 4s packs abc 1815 17 .

 

[bob miller]

thanks for the suggestions....bob

 

[johnmills]

Roaring Top Batteries ROARINGTOP USA are good 70C batteries, fast and durable. If you want to go nuts on an ESC the Castle Mamba XLX with a water-cooling conversion is a beast. I think the latest one is good for over 400 amps. Brian Buaas, raptor347 here on IW, does a cooling mod for somewhere around $75.
I'm told this guy runs, custom assembled, Roaring Top batteries

 

[bob miller]

Roaring Top Batteries ROARINGTOP USA are good 70C batteries, fast and durable. If you want to go nuts on an ESC the Castle Mamba XLX with a water-cooling conversion is a beast. I think the latest one is good for over 400 amps. Brian Buaas, raptor347 here on IW, does a cooling mod for somewhere around $75.
I'm told this guy runs, custom assembled, Roaring Top batteries

what are the advantages with using the castle manba xlx esc ?.....bob

 

[jayt]

For your boat, nothing. You don’t need more than the 150 amp Raider ESC recommended to you previously. I have been getting most of my FE stuff from offshoreelectics.com for two decades. Steven has a great selection, good prices on quality stuff and wonderful service.

 

[johnmills]

"For your boat, nothing."
Agreed, it's an expensive way to go that requires a cooling mod and waterproofing, which voids the warranty. The primary advantage is that you can pull a lot of amps if that's in your plans. For me, they've also been bulletproof, and I find the Castle interface/telemetry options convenient and easy to use.