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May 16, 2019, 09:25 PM
Registered User
Thread OP
Air, thank you for the kind words. The beauty of not being very good at something is that the learning curve is in your favor!

Kawasaki, your boat looks like it gets around pretty well. Well done! Looks like you're using the same receiver as I am, the 3 channel FlySky. Did you waterproof yours at all? I generally split the cases and fill it with epoxy, and sometimes solder on short female leads. I haven't had a problem yet, but the only exposed receivers I've used are on rock crawlers, I haven't tried an exposed receiver in a boat yet.

I installed my shaft seal and got the shaft and stator in today, as well as the steering rod. Short and straight, just how I like my servo linkages! I realized that the small brass tube I had installed for cooling wouldn't cut it, so I bent up a piece of 3/16" stainless brake line for what I think will be a better solution. Hopefully the bend doesn't have an adverse effect on cooling. I can always change it, but messy wiring and cooling lines are one of my big pet peeves, so this solution fit the bill nicely for now. It will slide out with the stator for maintenance, just need to unhook the cooling line from inside the boat.

The way I've positioned my motor jacket/ESC/cooling inlet should allow for nice straight hose connections (I hope!) although I don't have any silicone water line on hand. I hate paying shipping on little nickel and dime stuff like hose, so I'll have to make a list of other RC stuff I need to make it worth my while. All I need to order is hose and batteries (the last big ticket item).

And I still have to decide on some colorful airbrush accents.





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May 21, 2019, 10:36 AM
Registered User
I have not waterproofed anything so far and probably won't. I have the same receivers in two NQD boats, a pursuit, and my jet boat.
I did have a couple issues when I was testing the jet boat without a hatch on it and it quit working but once it dried out it was fine. I haven't had any issues since putting the hatch on though. I do get the occasional range blip with the pursuit but the jet never goes that far away.

Your boat is looking good. How long until the maiden?

Cheers
May 21, 2019, 08:18 PM
Registered User
Thread OP
Good to know you're having luck with the receivers. I haven't had one let me down yet in the 6+ vehicles I use them in, but I'm also very cautious to keep them as dry as possible.

I have water line coming, so the only thing left before she's a runner is batteries. I just purchased another gas boat, so toy funds are a bit limited at the moment. It may be time to unload a car or two since I never seem to get them out anymore.
May 21, 2019, 08:49 PM
Just Plane Nutts
AirDOGGe's Avatar
Receiver failures have not been a problem for me.

SERVO failures are another story completely. As soon as water gets into the lower casing my steering units start doing the jitterbug, limp to one side only or give up the ghost altogether.

Looks like your steering servo is mounted fairy low and vertical, so I'd recommend sealing the bottom of the servo casing or do what I do,.... open it up and spray the circuit board in the bottom with CorrosionX and never worry about it again (at least for a few seasons).
May 21, 2019, 08:53 PM
Registered User
Thread OP
I personally only run Savox waterproof servos, and have never had a problem. Not to say that anything's perfect, but I've had very good luck. I'll consider the Corrosion X though, I know it's good stuff.
May 25, 2019, 11:12 AM
Registered User
Thread OP
Another question regarding batteries. If I'm to run 6S (which seems to be the consensus) I'll need two 3S packs, both capable of at least 150 amps. Does anyone have a favorite source for these? All the ones I'm finding are quite large (and quite expensive!). I don't need crazy long run times, but obviously it's tough to get 150+ amps out of a smaller mAh battery.

So, who knows where to look?

All of my water lines are run, all she needs now is some batteries and a test pond. I'll try to get a shot up later today after all the chores are done.
May 25, 2019, 12:12 PM
Registered User
Kayaker's Avatar
I’d like to say there is a great battery that I have had good luck with but it’s not true. I get about two years and 150 charges so maybe I’m hard on batteries. Because I use a lot of power in a small boat I need high discharge, low resistance type batteries, mostly 60c. I kill low resistance batteries by discharging them below 3.5 volts per cell. The first cell to go below 3.5 volts can quickly drop below 3 volts and I get a week cell that goes down faster next time. I expect to replace a battery or two about a year in. I take enough batteries to the river to give an hour’s run time, typically 3-4 sets, 12-18 batteries.

I’ve been using 6 of these 3s batt’s in series and parallel to get 6s at 6600mAh in a 28 inch boat; https://hobbyking.com/en_us/graphene...5c-w-xt60.html

I use four of these (not pictured) to get 4s at 4400mAh in series and parallel but they can be connected with three in series to get 6s at 2200mAh. My boat pulls 106 amps so there would be a lot of voltage sag at 2200mAh’s giving a bigger possibility for bad cells so go bigger; https://hobbyking.com/en_us/zippy-co...lipo-pack.html
Last edited by Kayaker; May 25, 2019 at 01:41 PM.
May 25, 2019, 12:51 PM
Jetdrives R Us
sundogz's Avatar
You don't need 150A batteries, that figure (for the esc) is the upper limit the motor can draw, and your Tacon on 6S won't be pulling that kind of amperage. Just get a couple of 3S (or one 6S) 5000mah (or larger for longer runtimes) lipos with the highest C rating that you can afford. Anything will work, but avoid low C (like 10-15) which are meant for drones/quadcopters. Higher C ratings will allow for some extra poop if needed to avoid obstacles, etc.

You'll need a balance charger and power supply too, if you don't already have those.

I see you shop at OSE - they have a fair price on some 70C 3S lipos but they don't have connectors (why would OSE put ose-qs6p connectors on their esc when their batteries aren't sold with them?) so you will need to get some and do a little soldering. You'll also need a parallel harness and maybe a charge lead for their connectors (or make your own).

Personally, I'd cut that connector off the esc and go with XT60's. A lot of batteries (including those Zippy's Kayaler found) come with them installed.
Last edited by sundogz; May 25, 2019 at 12:56 PM.
May 25, 2019, 02:02 PM
Registered User
Kayaker's Avatar
When discharging 12 batteries a day I recharge using two parallel charging boards on a 20 amp charger; https://hobbyking.com/en_us/hobbykin...-6s-xt-60.html
May 25, 2019, 03:05 PM
Registered User
Thread OP
Thanks for the info guys!

I've already got a decent charger that I use for my RX batteries (LiPo and LiFe) and for the LiPos in my cars (that I never run anymore). However, I always make sure to get batteries that will provide at least the amperage my ESC is rated for. I have fried ESC's by using batteries that could not provide the necessary amperage. It's a painful and expensive mistake. I'm also plenty comfortable soldering leads, connectors etc. I always make my own to keep my wiring short and tidy.

Which is one reason I generally prefer hard packs with bullet connectors. I also don't generally like soft packs that live outside a sealed radio box in boats or cars that I know will get very wet. Moisture seems to find it's way between the heat shrink on soft packs. And I know these batteries will be getting very wet, probably with some salt water mixed in. My preferred batteries for my RC cars have generally been SMC batteries, although their selection and price for hard pack, high C 3S batteries seems to leave me wanting at the moment. The only one that looks something like what I need is this guy.

https://www.smc-racing.net/index.php...product_id=492

As for battery plugs, I've generally run Deans, but haven't decided what to go with yet on this project. The OSE plug that came on my ESC (specific to OSE, or....?) seems like an option for the primary parallel lead --> ESC, while maybe I use a pair of something else I have on hand for the battery --> harness leads? Not sure yet.
May 25, 2019, 05:51 PM
Jetdrives R Us
sundogz's Avatar
I'd be willing to bet that if you fried an esc it was because the motor asked for more amps than your battery could provide. This also puffs lipos. Using a high amperage esc (for headroom) doesn't require you to use amp-matched batteries, just some that will provide enough power for the motor under max load.

I quit using Deans a few years ago. They have half the contact surface area that XT60's have, and batteries equipped with XT60s are abundant nowadays. On boats pulling less than 60 amps I use XT60's, and all on all others I use 8mm bullets. It keep things simple.

That SMC hard pack should do the trick!
May 27, 2019, 10:00 AM
Registered User
I would also recommend to stay away from the Deans connectors. They will likely get really hot and create a lot of resistance in your wiring. I would run a minimum of XT90 in what you are building but would probably recommend an even larger bullet than that. I have XT90's in my boat and they get pretty hot as is with a smaller boat, 120amp esc, and smaller motor.

A 6mm bullet or the XT150 would probably be pretty good.

Cheers
May 30, 2019, 08:48 PM
Registered User
Thread OP
Got some batteries. Turns out my stash doesn't contain enough connectors to make myself a harness, so one more order it is. Anybody got a favorite place to buy plugs/connectors that won't bend me over the counter for shipping on a few small items?

Waterproofed and mounted my receiver (although the ESC/servo wires need tidying, they look a bit unkempt), and mounted an antenna tube. Water lines are on, and looking nice and clean if I do say so myself.



May 31, 2019, 03:26 PM
Registered User
Kayaker's Avatar
I buy harnesses already soldered together if I can. Here’s a list of some you can buy: https://hobbyking.com/en_us/batterie...-adaptors.html

I’m thinking you’re looking for a XT90 battery harness 10AWG for 2 packs in parallel for $7 USD; https://hobbyking.com/en_us/xt90-bat...-parallel.html

Your boat is looking real nice. I love the art work. Thanks for sharing.
May 31, 2019, 08:47 PM
Registered User
Thread OP
Kayaker, thanks for the link! I tend to get lost looking at Hobby King, their sub-menus for batteries, motors etc work well, but searching for accessories sometimes confuses me!


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