Converting a Northwind 40 to FE

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Spraguepsycho1

Well-Known Member
Joined
Nov 15, 2003
Messages
70
Converting a Northwind 40 to FE. Planning to use either a 4074 or 4082 2200kv Leopard, Seaaking 180amp esc, and 5000mah 50C (minimum) 4S batteries for fun running, with 6S for shorter duration max speed runs. Currently have a Castle Mamba Max esc rated to run their 4042 2350kv motor at 4S in Monster truck applications, so will be limited to 4S until I can afford the new esc. Not sure which motor I really need. I know the 4082 would have more torque and be able to spin a more agressive prop, but if the 4074 would be able to turn say a m645 safely using less amps than the 4082, I'd rather stick with the lower amp drawing motor if possible. I also see that a 4082 vmay not be working as hard, therefore not need as many amps to do the same work as the 4074 might need, so what would those of you with experience running heavier boats recommend. The M645 prop mentioned was just an example thrown out, I plan on starting tiwh a m440 3 blade, and 640 2 blade props for the first run or so and work my way up while keeping an eye on temps (Castle esc should thermal out before melting hopefully lol,) Look forward to some advise from the FE veterans here. Have another boat to put together once this one is running right.

John
 
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I Love these Boats I have three of them Never hit the water. Could you post a video would like to see it in action
 
John,

The Castle car controllers tend to thermal very easily in boats. If you do start with this, run very small props and check the temps. Although the Castle's do have thermal protection, this does not always work well. The T180 is a much better solution.

As for props the ones you mentioned should be good starting places with the T180. Remember to set the timing appropriately for the motor. A good starting place is 2-5 Degrees for Delta Winds and 5-10 for Wye Winds.

Try to make sure the boat is as waterproof as possible. This is the death sentence for the Castle car controllers which are not conformal coated.

Tyler
 
Tyler, Offshore Electric sells a watercooling plate that I was thinking about trying on the Castle esc, just pop off the cooling fan and mount the plate over the heat sinks. I tested the boat wirth an old 3650 motor last week, (5700kv on 2S), and quickly found out about the higher amp draws boats pull. Melted the + wire solder off my battery plug lol. Until then I wrongfully assumed that if it could easily push my 4wd TC4 touring car to 45+mph on 2S, it would have no problem spinning a lil ole 440 prop. lol On the + side, the speed control was still pretty cool to the touch, although the motor failed the 5 second test with flying colors. I'm not too worried about cooking the speed controller, as long as the boat doesn't burn up with it. Just gives me the justification needed to get the wife to cave in on the purchase of the 180a controller lol. When I tested the boat, I just used hatch tape on the cover I made. After 4 minutes of running, there still wasn't a drop of water inside the boat, so hopefully water ingestion will not be a problem. Once I get the system dialed in on this boat, I will most likely duplicate it for my other hull that my dad built for me last Xmas. It's a 36" all wood deep V that weighs about 1/3-1/2 as much as the Northwind. Should fly with the right setup if I can keep it on the water.

Mongoose 4.jpeg

Mongoose 5.jpg

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Mongoose 3.jpeg
 
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I would leave the fan on unless you plan on machining the fins down on the Castle. You need more surface area contact with the cooing plate to make it effective.

With FE there is always a risk the boat will burn and sink. Especially knowing know what happened.......
 
I would leave the fan on unless you plan on machining the fins down on the Castle. You need more surface area contact with the cooing plate to make it effective.

With FE there is always a risk the boat will burn and sink. Especially knowing know what happened.......
Ok will leave the fan on then. That never even turned on supriningly. I know it has turned on while in my car a few times, just never got hot enough in the boat. Part of the motor heat and melting solder may have been due to not enough power available from the battery I think. Battery was a 2S 5000mah 25C Venom battery pack. Motor never made it to full rpm with the 440 prop, but the boat did make it up on a plane. Question about running lipo's in series. When running in series to double voltage, does it also double the available current, say 25C+25C for 50C total? How about 2 25C's connected in parallel?
 
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Running batteries in series increases the voltage and maintains the capacity. Running in parallel increases the capacity and keeps the voltage the same. Paralleling has the same effect as adding the C rates, so 25C+25C=50C.

Running in series and doubling the voltage will cause more current draw, significantly more current draw unless you change the motor kv.
 
Thank you for that explanation. With the short hydro strut on this hull, the prop centerline is only about 1/2" below the keel, so the prop blades run higher than the keel (above the surface of the water once on a plane). Would this be considered a surface drive or subsurface drive? Only asking because on another FE site, someone mentioned that 2200kv might be overloaded running a 45mm or so prop subsurface on 4S. I was looking at it as a surface drive, which should (in theory at least) reduce some of the load as only a portion of the prop would be in the water once on a plane.What kind of speeds were these Northwinds running bitd? My dad said at Legg Lake (mid-late 70's when he started building this lol), they used to make them run in the hydro class because the other mono's weren't even close to being competitive against it. I'm hoping to at least get speeds in the 40mph range on 4S and 60mph range on 6S. Would those speeds sound reasonable for this hull design?
 
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Opened up the Castle esc and sealed it with epoxy. Hopefuly that will add a little extra insurance in case it gets a little damp inside the compartment.
 
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