ramrod18

Hi all,
I have a 40 inch catamaran that i would like to convert from a .21 nitro boat to a brushless boat. the nitro version was to slow and a pain in the butt. the problem is that i dont know much about brushless systems so i came to you for help.
I have about 500 bucks to burn and i want the boat to run in the 30 to 40 mph range. i also would like about 10 mins or more of run time. ( is this a realistic idea)

i need help with picking a ESC, Brushless motor, Battery system (including charger), and a prop.
i have been looking online for the past few days but i still dont have enough information to make a educated decision on these components. if you had these the criteria above what would you do?

Any help would be greately appreciated.
Thanks,
Ryan

doby

My Feedback: (1)

I'm puttng a similar size cat together right now.

Sorry to tell you that your budget will not be enough.

Neu 1527 motor,,,,around $270
Castle Hydra 180 HV around $300
For your speeds and run time, 8S LiPos and runnng in a 2S2P configuration, even if you went for the cheap Zippy brand,,, around $400 and run time will probably be in the 8 min range.
A decent charger around 250 that will do 2 batteries at a time.

Figure on at least $1300 to get you going as a CONSERVATIVE estimate.

Big boats are not cheap.

ElectRick

My Feedback: (2)

If it's speed you're after, you'd be money ahead in retrofitting a bigger nitro engine or a gasoline engine onto the cat.

For a 40" cat , you'd need something in a .80-.90 sized inboard piped nitro engine, or a 23-25cc gas engine to make that kind of speed. With only a .21, it was extremely underpowered, to say the least.

Rick

ramrod18

Im not really after to much speed, where i live i dont have a nice calm lake or pond i would be running this in a moderiate chop, i rather have run time then being able to do 60mph i think, i am going to get a 26cc gas engine and try that. but im not 100% sure yet. after what i have read and concedering my options going gas would be cheeper (i have no electric components) and it would give me more run time then an electric. so as of right now im leaning on the gas side.
any information would be greatly appreciated.
Thanks,
Ryan

deslok113

Check this website out:  http://www.hobbycity.com/hobbycity/s...=4&v=&sortlist=   I've owned a few of these motors and they are awesome.  The best thing about them is the price. Read the reviews on the site and see for yourself.  They also sell ESC's and other accessories but I usually spend the extra money in the ESC dept.  If you look at the top of this speed electric forum there is a guide on building BL electric setups.  I've found the information invaluable.  I'm currently building a FE 40" V-hull that had a .65 OS Max vr-m in it.  After many head aches with nitro marine engines, I now only have Nitro aero engines for my airboats and FE boats.  For Power go LiPo, check ebay,  yes ebay!  I bought several Lipo's of good quality on ebay.  For my BJ 26 BL I bought 2 7.4v 25c burst 35c 4000mah 2s1p LiPo packs for $56 for the both of them!!!  I've run over 10 charge / discharge cycles through them with no problems.  Using my Big boat as a chase boat, the big boat's speed-o-meter said between 40 and 45 mph, dead center, so I estimate 43mph.  Also for an old Cen Baja that I put a 775 in with brushed ESC and LiPo BL voltage cutoff device; I got a 14.8v 35c burst 40c 3000mah 4s1p LiPo pack for $60, again on ebay!!!  So far I've run it through about 5 cycles with no trouble  (sorry no speed data on this one as it hasn't been on a "fishing" trip with me yet ).  Contrary to popular belief you don't have to spend a fortune to get good quality hobby grade R/C stuff.  You just have to do good web searches and make sure you are dealing with reputable websites.

ElectRick

My Feedback: (2)

Even given the availability of the inexpensive KB motors and cheap Ebay LiPos (I have a few of them too), gasoline is still a far cheaper way to go with this hull size range.

There is still the ESC to consider, and the ESC can't be a wimpy one for the kind of current the big KB motors will have to draw to push a 40" hull through chop. I'd recommend no less than the Turnigy 120 amp one, and that adds another $80 or so to the tab for going electric. Gasoline will give much better duration too, since it is only limited by fuel tank size.

Rick

deslok113

Rick is right don't skimp on the ESC.  I usually use cheapie motors and batts but unless you like the smell of burning electronics don't skimp on the ESC.  The esc I'm using in my 40" boat is a Turnigy 120amp 3s to 12s ESC, it cost me a little over $100.