I've had this old boat sitting around for many, many years and just started toying with it. My experience with nitro in general has been pretty inconsistent, so I'd be a lot more comfortable putting it in the water with an electric motor. What I don't have any clue about is what kind of motor and ESC I'd need. The boat is a fiberglass v-hull about 32" long and 11" wide.

I don't really care to go super fast, just fast enough to enjoy. I do have a handful of 2S 30C lipo batteries laying around so I plan on getting an ESC with a low voltage cutoff and Iwould like a brushless motor. Any tips or links to guides would be very helpful. Thanks!

Pics and more here: http://www.rcuniverse.com/forum/m_10577918/tm.htm

If you want something to read and familiarize yourself with, visit [link=http://radiocontrolinfo.com/Electric%20Build.html]RC Electric Brushless.[/link]

If you are looking for a reliable setup, I'd choose a motor around 2000kv 540l size can. ESC similar to a hydra 120. 42mm prop to start.

Ryan

my vegas deuce is 33 " long i put a turnigy 180a esc and the 9xl hobby king motor in with 6s y535 octura and i cannot pin the throttle and hold it for more than 3 seconds as it just keeps going faster theres lots of setups just depends on what you want and how much you want to spend

3rd run out with the turnigy and it melted down can we say junk ?

Alright, I got a motor and ESC and have a few more questions.

1) How do I couple the motor shaft to the prop shaft? The motor is 5mm and the prop shaft is flexible and appears to be about 5mm as well. I've been to the local hobby shops and they don't know anything about boats.

2) I ended up with a 2300kv motor. I have a bunch of 2S 40C lipos with the 38mm prop. How many cells am I going to want to run, at least for starters?

3) I'm concerned about cooling. The intake is just a 1/4"ish copper tube on the back of the boat, and I'll probably end up with about 2 feet of tubing inside. Will that be enough to cool both the motor and ESC? Should I route the lines in series or parallel?

4) The batteries and ESC are going to be mounted under the cowl that is fixed with screws so I won't have easy access to them. How can I wire a switch for my ESC? The ESC I bought doesn't have a BEC or a switch. I'll throw an external battery pack in for the receiver and servos. I can't run all that current through a switch, should I use a relay? Can anyone recommend one?

Thanks again for the input! I'll probably have more questions before I'm finished..

have u got pictures? what kind of boat? firstly we need specs on motor esc etc. you have to buy a coupler for instance my motor shaft is 5 mm and im using stock hardware on my deuce so i know the flex cable is a .150 to a 3/16 shaft turned down to 1/8. so i purchased a  5mm coupler to fit for .150 flex. im running the traxxas velion esc and know it can handle 6s. so i run 2  3s lipos in series to achieve the 6s instead of running 1 6s  lipo.
as far as cooling you might want to look into getting a rudder with a water port or 2 even to run seperate cooling lines 1 to esc and 1 to motor or y off your cooling lines some do not do this because there is a chance that the esc is getting the water and the motor isnt geting enough hence 2 seperate water lines with 2 outs and you can see the water flow out  on a pass to know your getting the water in through the components. send pics ehh and get make and model of the esc and motor.

what motor did you choose?

I don't have a clue what make or model the boat is it's at least 25 years old and I have no idea how I'd go about finding a model for it. The original motor was a nitro HP .40 that I didn't even want to mess with so I bought the electrics.

I bought this 125a Hobby King ESC and this 2300kv motor. I actually used this 2560kv motor when Itested it this weekend, though (long story, but it's not watercooled and got pretty warm so I won't be sticking with it, I'll use the first one). The 2300kv I'll be using is only rated for 11v, the ESC for 7S. I'll probably end up wanting to upgrade the motor, but I have a couple other issues I want to solve first.

Idid finally get the boat out on the water over the weekend, with the 2560kv motor. It was quite a bit faster than I expected using a single 2S 40C lipo, but Idid have a couple problems.

1)Since the motor Iwas using wasn't water cooled, I obviously had my water lines running through just the ESC. It didn't get any water at all. I did buy larger diameter fuel line yesterday, but I would have expected to get at least SOMETHING.. There's a single copper pickup tube in the back. There are no clogs or kinks. No idea what I need to get enough (or any) water to my ESC..?

2) The prop is cavitating a lot. It has no problem getting up on plane but as soon as it does it cavitates. The prop is bigger than was recommended above as I wanted to get a baseline, about 55mm. No idea what the pitch is, but this IS a prop that was originally chosen for the nitro motor, and it's plastic. I ordered a few different sizes, 35, 45 and 50mm, to try out. I also lowered the prop about 1/4" but can't go any further without making modifications and didn't want to do it until someone told me that makes sense.

It's difficult to explain the reasoning of the water cooling without being able to see the rear of your hull. If the speed is high enough water should be forced through the system.

The link for the 2300kv motor is not specific. Clicking it brings up a page with a list of motors. I hope this motor is a similar size to the 2650kv motor you linked.

If this hull is surface driven, your prop will aerate upon getting on plane. Prop Aeration will occur in the transition from 0mph to on plane for a surface drive hull.

The 2650kv (link says 2560kv) motor should work on 2s and 3s. On 2s, you should be able to run the 50mm prop. On 3s, I'd start at 38mm or so. What is too warm? 140F is the typical maximum for electric in my books. By the touch this feels "hot" to my touch. You will want to get the motor water cooled. It will greatly help.

Do you have a photo of the rear? The best would be a direct view from behind to see shaft height in relation to the hull and your water pickup.

And as always, watch the heat and keep your run times very short. This is until you get a setup dialed in.

Ryan

The water cooled 2300kv motor is shorter than the other. This link should work: http://www.hobbyking.com/hobbyking/s...ner_Boat_.html What does surface driven mean? I would eventually like to get a bigger motor and run a 4S battery but I want to get everything sorted out at the current speed before Ithink about that.

I didn't have my temp gun with me, but the motor didn't get TOO hot, maybe 150ish (by feel), not too hot to touch. That was with a very short run time. The ESC got hotter than the motor. I'm sure still under 200 degrees, but too hot to hold a finger on. Definitely want to get it cooled. I'll try to get a photo of the back up tonight. The water inlet is probably a good inch below the hull, just offset from the center line.

Aerating would mean the prop is actually breaking the surface of the water, while cavitating would be creating a pocket in front of or behind the prop, right?

Edit: Also wanted mention that there WAS just a tiny bit of a sweet spot between when the boat would plane and when it would cavitate or aerate or whatever it's doing. So it could run on plane, if just barely.

The main goal is to make it fun without investing a lot of money. I play with cars a lot more because Ican do it around the house and without the fear of needing to load up my canoe. The boat is more of a "this thing has been sitting for 25 years, it's time to get it in the water" deal.

Aeration vs Cavitation is often confused and misused.

Cavitation is actually the formation of bubbles from large pressure differences. You would not be able to hear this occur.
Aeration is probably what you mean. When the prop grabs air and the motor revs up, this is called aeration. Aeration makes getting on plane for surface drive hulls much harder. This is due to the prop making the transition from submerged to properly coming out of the water.
Surface Drive vs Submerge Drive. Most full scale recreational boats have a submerged drive. This is where the prop remains under the water surface at all times.
A surface drive is where the hull on plane has the prop half in the water and half out. This is nearly standard on all recent RC boats.

The 2300kv motor actually looks a lot smaller than the trackstar motor. I would almost feel more confident running the trackstar motor on 2s or 3s max. This may be better suited vs the 2300kv motor.

Motor dimension are listed at
28 x 56
vs
40 x 68

Big difference in available heat dissipation if these specs are accurate. The larger motor will be able to dissipate more waste heat staying cooler over time.

140F is the max I would like to see.

Ryan
[link=http://www.radiocontrolinfo.com/forumindex.html]RC Forum[/link]

Those specs must be a bit off. The cans are actually the same diameter (give or take, the trackstar is a BIT oversized for a 540 can), and with the water jacket the blue one is obviously a bit bigger. I believe I measured the lengths at something like 58mm for the blue one and 72mm for the trackstar. Anyway, the trackstar is going to go in a buggy and I don't think I'd have a fun time trying to find a water jacket to fit it, so if the blue one doesn't work out I'll buy something else. I just wanted to get something cheap in there to see what the boat was going to do.

I don't know that I can really "hear" whatever the prop is doing, but I do think it sounds more like aeration now that you've described it. Does that mean I have the wrong type of prop?

I don't even know which prop you are using. My point was surface drive boats will aerate. It's quite normal if yours is of that type.

It would be easier for us to understand what is happening with your hull if you make a short video.

Ryan

My neighbor snapped a couple pics.Light wasn't very good but here's what Ihave.

It'll be at least a week before I get this thing in the water again and can make a video. What it's doing is accelerating just fine, planing and then eventually the motor will rev up and the boat more or less stalls until you let off of the throttle and slow the motor back down, and then it will "bite" again and go.

I'de say your strut is way way to deep...

Ah, this is really old school. You are running a setup that no one really uses any more. That is indeed a fully submerged setup and NOT surface drive.

This does effect your motor decision and prop choices if you wish to continue running a fully submerged setup. You will want a motor with less KV, and a smaller prop since it will be in full contact with water.

To be honest, I would seriously consider a surface drive conversion. Everyone when making recommendations assumes it would be this way.

More information for a monohull can be read on the [link=http://radiocontrolinfo.com/ElectricBuild/mono.html]Mono Hull[/link] page. Notice the circle in the drawing on the transom? That is the typical prop shaft exit location for a mono.

Ryan

I'll try it out again with the prop lowered a bit and see what happens. If I'm not happy with it I think I'll go ahead and convert to surface drive. Same deal with cooling, if the bigger fuel line doesn't give me the water I need I'll buy a new rudder with a water pickup. I did find some time to get on your site last night and did quite a bit of reading, lots to learn.

The water outlet is currently right next to the motor directly out the bottom of the hull. It sounds like it's more common to have water coming out the top or side of the boat is that right? If I change that (and if I convert to surface drive), what's the best way to fill holes in the hull? An epoxy resin? Thanks again for the help!

Yes, the typical exit is at the side (port) of the hull. This way you can see the water flow during a race or run. It's important to know how much water is flowing.

Epoxy would be best for smaller holes. Larger holes may micro balloons mixed in or a piece of fiberglass cloth.

Ryan

I'll definitely relocate the water outlet then, because I won't have any clue how much water it's flowing (unless the lines are dry, like in my test run).

forgive me if i am wrong but if the water outlet being under the boat and running, if that water outlet isnt out of the "wet area" of the hull wouldnt the water be trying to force up through the pickup and up into the outlet?

Yes it would. even if this is past the wet surface, every splash or wave will stop, reverse, or slow the water flow. Water exit should be done where it is visable. Out the side seems to be the most common. It provides a shorter run, though if you rout back to the transom and out, you can take advantage of a siphoning like force with the forward movment wihich may counter the friction loss of the extra lenght. (bla bla bla, it may not actualy make a difference weather you exit out the side or transom)

Just make sure you can see the water flow, and it is out of any spray.
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