Hi Guys,

I have a 1100mm long cat that is dual driven that I have taken the running gear out of and put it into my Mystic cat. I want to keep this cat at a budget, so I was thinking of buying motors and esc from Hobby King.
My question is what motors and esc would you guys recommend for this size boat. Battery wise I dont really want to go higher than 5s lipos. The lipos will be 25 or 30c 5000 mAh.
Im not looking at super fast speeds, just something that will be fun.
Thanks guys

i have a similar cat, in mine i'm running 2 x 2s, 4000mah lipo's, single 4200kv, 3848 (38mm diameter x 48mm long) 100a pentium speedo, 1/8" flex cable and strut setup, maybe this can be a basis for you

in your boat i'd say 35mm or up motor, whatever you can afford, you could use 2 x 2s or single 3s, 4s batts, its upto you

to work out what RPM's you want use motor diameter size x batt voltage then you'll have an idea how fast you want it to go
amps in a battery is what gives it the speed, more amps, more power

There's a fantastic thread at the top of the forum with some details on how to choose a system.

Go with the highest voltage you can budget. I'd suggest 6s minimum for such a large hull. You will want to use a motor such as the Feigao 580 series, pick an appropriate wind to match your LiPo choice. Pick cells with minimum 25C and 5000mAh. 3/16" Flex should be a minimum.

So there's no confusion. Kv X voltage = unloaded RPM. This does not determine how fast anything will go but may determine how quickly your electronics will fail.

Ryan

ok If I go with 6s, what motor brand would you guys recommend and what esc would you recommend? Remember I want this boat to be a inexpensive build. Also where would be the cheapest place to buy the goodies?

well i always go on ebay and get the stuff i need from there but where i live i also get my stuff from astecmodels.co.uk

Nick................it sounds like your motor would strain quite a bit and run hot.............a 4200kv only 48mm long in a 40+" boat........did i read that right? Man if it works thats great, but i would think more like a 36x74 feigao 12XL-14XL on the 6s would be a cooler running setup at the minimum and certainly Ryans suggestion of the 580L would be optimal......just my 2 cents.....i've been known to be wrong before though.

Nice lookin' boat Wet...........

rebuilder, your correct, got it down the lake today and put it in the water, i could p*ss faster than it went, but your right on the motor, i will be going with the motors people suggest, thanks for pointing it out mate

i've had a look at the fiegao motor (580) and worked out that with a
- 6s would give 101587.2 rpm's
-3s would give me 50793.6 rpm's

and so on, i was thinking of 2 x 3s to balance the boat as i already have the battery mountings in place, im just worried that the motor won't cope with the power

I dont know which one you're looking at but i dont come up with anywhere close to those rpms Here is the rundown on the motor on offshoreelectircs.com :

Product ID: fei-580-L
Feigao 580L "Long" Sized Brushless Motor Details


Feigao 580L "Long" motor for use with 30" - 40" mono or hydro boats. This motor will produce up to 1800 watts with the proper cooling.

If your a sport boater or top notch racer on a budget, the Feigao Line of motors is the Brushless motor for you! Feigao high performance brushless motors have the rpm and motor efficiency similar to motors like Hacker that are 2 to 4 times higher in Price!

feigao 580L: 580 6L 2,154 RPM / Volt (5)
580 7L 1,894 RPM / Volt (6)
580 8L 1,649 RPM / Volt (12)
580 9L 1,426 RPM / Volt (0)
580 10L 1,326 RPM / Volt (5)
580 12L 1,051 RPM / Volt (4)

the 8L will give you around 38,000 unloaded, that is more in the reasonable range, the 9L about 33,000.................

An inexpensive build as you're wanting, may include something along these lines................these items are less expensive and are not the "best of the best" but i run the big KB in one of mine, these are simply inexpensive:

http://www.hobbycity.com/hobbycity/s...hless_Inrunner

http://www.hobbycity.com/hobbycity/s...hless_Inrunner

You cant run the big KB on this, but the other motor will be fine:
http://www.hobbycity.com/hobbycity/s...hless_Boat_ESC

Run either on this:
http://www.hobbycity.com/hobbycity/s...hless_Boat_ESC

What is the number in the ( ), is that simply the number of items in stock, or does it have something to do with the motor Kv rating?
<br type="_moz" />

Yeah................its their current in stock Inventory..............the 9L must be popular.

hey rebuilder, the closest i can get to the suggested motors in england (with royal mail striking and making idiots of themselves, i dont really want to shop abroad) is 

 - KB 45 11L (1649kv) max 70a
 - KB 3674 09XL (1900kv)
 - feigao 8L (1649kv)

having looked i can go with either  3674 or the 8L

thanks for the reply rebuilder,
My main concern is that Ive read that the KB45 seem to run really hot. Is this true and if so what other motors would you recommend?

as long as the can is kept well cooled then i cant see any problem with it

try fiegao motors, 540/580 long motors

use a cooling jacket as close to the full lenght of the can as you can get, most need to be drilled for the nipple's so mount either end and opposite eachother so you get no air bubbles when water passes through

The KB's do run hotter....................the Feigao 580L is more efficient, but, its also 50% more cost. I keep thinking of your "inexpensive build" concept.

<font color="#000033">hey guys?!</font> <div><font color="#000033">i really need to know </font><font size="+0" color="#000000" style="BACKGROUND-COLOR: #ffffff"><span style="FONT-FAMILY: Arial; COLOR: blue; FONT-SIZE: 9pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA">bout the thinks i will buy if they're can work thogeter with no problems, battery, charger, motor...</span></font></div><div><font size="+0" color="#000000" style="BACKGROUND-COLOR: #ffffff"><span style="FONT-FAMILY: Arial; COLOR: blue; FONT-SIZE: 9pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA">i wanna put all this in a boat that i made, it`s 37 inch and 650 g  about 1 m longer, not for competitiom only for fun, it`s a catamaran max cat 1, well, this things can work thoghether?</span></font></div><div><font size="+0" color="#000000" style="BACKGROUND-COLOR: #ffffff"><span style="FONT-FAMILY: Arial; COLOR: blue; FONT-SIZE: 9pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA"></span></font> </div><div><font size="+0" color="#000000" style="BACKGROUND-COLOR: #ffffff"><span style="FONT-FAMILY: Arial; COLOR: blue; FONT-SIZE: 9pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA">- motor</span></font></div><div><font size="+0" color="#000000" style="BACKGROUND-COLOR: #ffffff"><span style="FONT-FAMILY: Arial; COLOR: blue; FONT-SIZE: 9pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA">3660SL 3060kv Brushless Inrunner (WaterCooled)
Kv: 3060rpm/v
Diameter: 40.30mm
Length: 75mm
Shaft diameter: 5mm
Weight: 299g
Battery: 2~3S 3,000mAh
</span></font></div><div>Standard size mounting holes enable the motor to be installed in a large range of motor mounts.</div><div> </div><div>- eletronic speed control</div><div>Turnigy Marine 35A Brushless Boat ESC

With an ultra fast CPU and USA power FETs, the Marine brushless esc is a high performance ESC capable of standard and competition use.

<span>Programmable settings;
Reverse
Low Voltage (none/2.6v/2.8v/3v/3.2v/3.4v)
Brake: (none/soft/hard)
Timing (0.00/3.75/7.50/11.25/15.00/18.75/22.50/26.25)</span></div><div>
Constant Current: 35A
<span>Burst Current: 190A
Resistance: .0015 ohm
Battery: 2-3S Lipoly
BEC: 6v/ 1.5A
Motor Type: Sensorless Brushless
Size: 31.5 x 27.5 x 16mm
Weight: 32g</span></div><div> </div><div>- battery</div><div><font size="3">Turnigy 3000mAh 3S 40C Lipo Pack</font></div><font size="3"></font><div>Spec. Minimum Capacity: 3000mAh </div><div>Configuration: 3S1P / 11.1v / 3Cell </div><div>Constant Discharge: 40C </div><div>Peak Discharge (10sec): 50C </div><div>Pack Weight: 278g </div><div>Pack Size: 145 x 43 x 21mm </div><div>Charge Plug: JST-XH </div><div>Discharge plug: 4mm Bullet connector </div><div> </div><div>- charger/discharcher/balancer</div><div><font size="3">GT A-6 Charger/balancer/discharger</font></div><div>

Features;
Microprocessor controlled
Delta-peak sensitivity
Individual cell balancing
Li-ion, LiPo and LiFe capable
Ni-Cd and NiMH capable
Large range of charge currents
Store function, allows safe storage current
Time limit function
Input voltage monitoring. (Protects car batteries at the field)
Data storage (Store up to 5 packs in memory)
Battery break in and cycling.</p>

Spec.
Input Voltage: 11~18v
Circuit power: Max Charge: 50W / Max Discharge: 5W
Charge Current Range: .1~5.0A
Discharge current range: .1~1.0A
Ni-MH/NiCd cells: 1~15
Li-ion/Poly cells: 1~6
Pb battery voltage: 2~20v
Weight: 580g
Dimensions: 133x87x33mm</p>
</div><div> </div><div>-servo</div><div><font size="3">Power HD Metal Gear Servo 60g/15.5kg/.16sec</font></div><div>Model: HD-1501MG
Voltage: 4.8~6.0v
Speed: 0.16~0.14sec
Torque: 15.5~17.0kg/cm
Weight: 60g
Size: 40.7x20.5x39.5mm</div><div> </div><div>- control</div><div><font size="3">Hobby King 2.4Ghz 4Ch Tx &amp; Rx (Mode 2)</font></div><div>-channel 2.4GHz transmitter with servo reversing.
Easy to use control for basic models.
Includes 6-channel receiver
Trainer system option.
This system does not need a PC to program servo direction.
<div><div>Included;
1 x 2.4Ghz transmitter
1 x 2.4Ghz Receiver
1 x Bind Plug.</div><div> </div><div>and this is my doubt - ubec or ibec?</div><div>does i really need?</div><div>which one?</div><div> </div><div>- ubec </div><div>hexTronik UBEC.
Will supply a solid 5v or 6v to your reciever with a  2 to 5S Lipoly pack.


Specifications;
Output: 5v/3a &amp; 6v/3a (Selectable via jumper)
Ripply: &lt;50mVp-p(@2A/12V)
Input: 5.5v~23v (2 to 5s)
Size:41.6mm*16.6mm*7.0mm
Weight: 12.5g</div><div> </div><div>- ibec</div><div>iMAX iBEC 6A Linear Regulator &amp; Glow Plug Driver.
</div><div>Spec.
Input: 2 cell lipoly
Output: 5.3v BEC &amp; 1.4v for glow driver
max Current: 8A
max Cont. Current: 6A
Weight: 58g
Size: 82x31x14mm


</div></div></div><div>PLEASE CAN ANY ONE HELP ME?</div><div> </div><div>i live in brazil, this kind of hobby isn`t popular here, and i don`t know any one else who can help me on this doubts, i search somethig to read but did`nt find so much...</div><div>if does any one can help, please i`m waiting. </div><div>thanks leo</div><div> </div><div>ps, all this products are on this link:</div><div> </div><div> <u><font color="#0066cc">http://www.hobbyking.com/hobbyking/store/[email protected] m&amp;idCustomer=190844</font></u></div><div> </div><div>its my wish list on hobby kink,</div><div>only place that i`m allowed to buy...</div>

telleslattari

Just from a quick glance that motor will not work.....................much too small. Its actually a 36mm width and 60mm length, they are including the water jacket and shaft in the measurements. 3s lipo is not enough to run that boat either...............4s at the very minimum and 6s is best. A much better setup than the one you posted would be this motor:

http://www.hobbycity.com/hobbycity/s...hless_Inrunner

With this speed control:

http://www.hobbycity.com/hobbycity/s...hless_Boat_ESC A 35 amp speed control is WAY too small

On two of these batteries in series for 6s:

http://www.hobbycity.com/hobbycity/s..._20C_Lipo_Pack

This is just something to start with that is much more feasible than your ideas. Good luck!!

rebuilder is correct, i am putting the same setup in my 30" catamaran, but i will be using 2 x 3s lipo for balance reasons, but the motor and ESC is what i am using, just waiting for them to be delivered now

I did think of one thing while going back over the thread..................i had in my head the KB motors or the 13xl's which are both uinder 1600 kv, the 1900 540XL is gonna be runnin' a little over 40k rpms............thats just pushin it a bit.............i personally would probably do it, but just a word of caution.

im going with the kb 3670 (1400kv) 2x 3s, 3600 mah, 25c (constant discharge) everythings waterproofed and watercooled so hopefuly it will run fairly cool as i chucked the usual cooling pipes and putting in 3mm (inner diameter) cooling pipes, mite try it 1st with my 3s 2200mah batt's to see how she runs, when i'm down the lake i'll do a video and post it

like you rebuilder, i like to push it, that way i find out the limits, if it sinks, it sinks, i just start again, but i have found out that the setup should be ok, if not then i just move on

A 1400kv should be real good for rpms, right in the low 30k range on 6s.

so is that a good choice then

hi nice people!
thanks for the adivices,
now i thing that i'll use this motor:

KB45-12L 1400kv Brushless Inrunner
Kv: 1400RPM/V
Weight: 449g
Shaft: 6mm
Size: 63x45mm
Voltage: 36v
Highest rated power: 2246W
This size motor will fit our larger 5inch and 4.75inch EDFperfectly. (same mounting holes &amp; shaft size)

with this lipo battery:

<font size="3">Turnigy 5000mAh 6S 20C Lipo Pack</font>
Minimum Capacity: 5000mAh
Configuration: 6S1P / 22.2v / 6Cell
Constant Discharge: 20C
Peak Discharge (10sec): 30C
Pack Weight: 793g
Pack Size:148 x49 x 49mm
Charge Plug: JST-XH<div>Discharge plug: 4mm Bullet-connector

does it mach?
what you guys thing?

sorry for the ignorance, but here in brazil this kind of hobby is extremely dificult access, since i was a kid i wanna a rc boat, now i`m constructing one.
its a cat like the picture up this page, soon ill post a foto.</div>

far as i can see that setup will be fine

flex shaft setup will be better than straight shaft as flex shaft is adjustable
make any curves as gradual as you can
and
start with a small prop and work up from there till you find the right prop for your boat

Sounds like a nice setup!! You may want to consider two 3s batteries connected in series to obtain 6s so you can balance the boat better.....one on each side. Here is the speed controller i would recommend: http://www.hobbycity.com/hobbycity/s...hless_Boat_ESC

And battery, X 2 :

http://www.hobbycity.com/hobbycity/s..._20C_Lipo_Pack

Do not use too big of a prop....................42mm or less for surface drive would probably be best.