Help Me Build My First FE

**eboat** · 06-07-2009, 08:36 PM

I do not think you will get to run an electric boat at 50-60 mph for 15 minutes
If that is what you want you should be thinking about nitro

At that speed 5-6 minutes of run time would be good

The hardware looks OK and the cable is a bit large but it will not break
.150 cable might work better (less drag) and save the .187 for later when you go all out for speed

**Fluid** · 06-07-2009, 08:50 PM

The HOTR cats are copies of an excellent German design, some of these chinese hulls are warped, some are not. The motor is a pretty good choice for this hull for speeds in the 30s and decent run times. Get an OSE cooling jacket for it.

Don't use the 0.187 cable/hardware, it is too big heavy and stiff, and will eat up too much energy. Get the correctly-sized hardware for the hull. Look at the many HOTR builds on the forums for ideas - the search engine is your friend. 0.150" cable is plenty strong.

If you want long run times then get a 4S2P LiPo setup. This configuration can be obtained several ways, my suggestion is to get two 4S1P packs with at least 3300 mAh (4000+ is better) and a 20C minimum rating. Wire the two packs in parallel. That will give the correct voltage - 14.8 nominal - and 6600 mAh or more capacity. Do not run more voltage on this motor in this larger hull.

You only need one water pickup - run the water through the ESC then the motor. As an ME student you will learn from your professors the value of KISS.

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**j.m.** · 06-07-2009, 09:07 PM

I've heard the mold for that hull is warped...

I don't think you can get to 60 with it.

**Eodman** · 06-07-2009, 09:21 PM

Warped or not build this hull - learn on this hull - make your mistakes on this hull & then if you become addicted like the rest of us you will be ready to make the jump to a much better hull!

Most of all ... don't get discouraged!

Well that's all Ii got!

**Evan Fullerton** · 06-07-2009, 09:43 PM

I have the hull in hand and it is not warped. As far as the construction of it, I think that it is pretty good. I may not have much RC experience but I have spent a lot of time around full size boats and the fiberglass work is as good or better than any of the real boat I have dealt with (I lived on a 35' sail boat for 3 year, and am a dock manager for a local restaurant, I see a lot of different boats). I read the debate over polyester vs. epoxy and I agree that epoxy is better but every production fiberglass boat made up until 5 or so years ago was made using polyester so I see no issue there. It was easier and cheaper to buy this hull than the original (I would have if I could read German) but for a first boat it will be fine. I believe Chinese products are just like the ones that come from every where else, in the respect that you don't want one made on a monday

the only difference being China does not have the quality control to not ship the substandard parts.

I really liked the lid to hull joint on this cat so I bought it, time will tell how it holds up. I plan to add some balsa ring frames to the hull as with as much cavernous space as it has the large flat sections are not as stiff as I would like, leaving the potential for gelcoat cracking in a high speed blow over.

In regards to the KISS comment, I agree simple is good but I am also a big proponent of overbuilding things and sometimes those two theories come at odds with each other. My race car is a 1973 Porsche 914 that is pushing double the HP that it was originally designed for and I can't change to a larger displacement lower stressed engine due classing reasons so I am stuck with the temperamental engine; the 10" wide slicks don't really decrease the stress either

but needles to say I break enough stuff on that so I really only want to do this boat once. I have yet to learn the cooling requirements of brushless motors and ESCs but I will start with one inlet and if things get much above 110-120F I will add the second one.

Thanks, Evan

**Evan Fullerton** · 06-07-2009, 09:56 PM

I should add that this boat will be run almost exclusively in salt water. I live too near a harbor to do anything else. This was the primary reason not to go gas as that wold be work keeping that flushed and I have not seen scale heat exchangers. Also, the problems of hitting kelp at speed should not be overlooked. I will have to build this thing stout.

**wolf IV** · 06-07-2009, 10:20 PM

Originally posted by Evan Fullerton

I should add that this boat will be run almost exclusively in salt water. I live too near a harbor to do anything else. This was the primary reason not to go gas as that wold be work keeping that flushed and I have not seen scale heat exchangers. Also, the problems of hitting kelp at speed should not be overlooked. I will have to build this thing stout.

IVE ONLY RAN IN FRESH WATER TWICE.. EVER..

I LIVE UP THE STREET FROM DANA POINT HARBOR AND ITS MY ONLY OPTION WITH TWO BOYS AND WIFE.. I PUT ALOT INTO MY BOATS, WHEN I SAY THIS I MEAN TIME AND MONEY .. SALT WATER AND DEBRIS WILL COST YOU LOTS OF $$$ IVE LOST SEVERAL PROPS, FLEX DRIVES, ESC'S , RUDDERS AND SERVO'S...ALL BECAUSE OF THE SALT/CORROSION / DUCKS /DEBRIS.... YOU REALLY HAVE TO MAKE EVERY PROCAUTION POSSIBLE TO KEEP WATER OUT OF THE HULL.. EVEN MORE SO BECAUSE OF THE SALT.. ALWAYS BLOW OUT YOUR COOLING SYSTEM AND GREASE FLEX DRIVE, INVEST IN SOME CANS OF CORROSIONX AND SPRAY EVRYTHING IN YOUR HULL THEN LIGHTLY WIPE OFF EXCESS. DONT LET THIS DISCURAGE YOU AS THIS HOBBY IS SOOOOOOOOO FUN , JUST DONT SLACK ON PREV.MAINT. AS THE CONDITIONS ARE MUCH HARSHER...WHERE DO YOU LIVE? P.S IM BUILDING A TWIN- CAT AS WE SPEAK, GOOD LUCK!!!!

**Evan Fullerton** · 06-08-2009, 12:51 AM

I am not too far away from you. I am up here in Costa Mesa. A good friend of mine has a couple RC boats and is building 2 hull just like mine. We run them off the back of his yacht in Newport with a whaler for retrieval. Works out quite well. Once I get this thing running it would be great to get a bunch of people together and set up a course in the Back Bay. I figure that this is not a cheap hobby but it seems as though it should be considerable cheaper than a day at the track with my other toy.

**wolf IV** · 06-08-2009, 01:26 AM

Originally posted by Evan Fullerton

I am not too far away from you. I am up here in Costa Mesa. A good friend of mine has a couple RC boats and is building 2 hull just like mine. We run them off the back of his yacht in Newport with a whaler for retrieval. Works out quite well. Once I get this thing running it would be great to get a bunch of people together and set up a course in the Back Bay. I figure that this is not a cheap hobby but it seems as though it should be considerable cheaper than a day at the track with my other toy.

sweet! well keep me posted , ill add you as a friend so we stay intouch as i have yet to run with anyone in the 3 years ive been boating..

**Fluid** · 06-08-2009, 07:36 AM

....I will start with one inlet and if things get much above 110-120F I will add the second one.

You will find that no matter how much cooling water you use, your electrical components will get above 120F if you run long enough fast enough. The water cooling seldom gets to the important parts, and what it does cool it usually does rather inefficiently. If you expect to run for longer than 5 minutes over 35 mph on a hot day expect certain parts to exceed 120F routinely. Running in the ocean will help some as the water is cooler than most fresh water bodies under the same ambient conditions. A limit of 135-140F is more realistic.

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Help Me Build My First FE

Help Me Build My First FE

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