Hi,
I recently found an old RC boat and i want to restore it, the problem is that the electonics are old too, and i also think the motor is too powerfull for the battery. So here's the electronics:



The motor is a Roar 96 kyosho 27 turn (i dont know anything more about it). So what i want to do is update this setup but i want to keep the electonics because they are all working fine.

Any tips ? :P

PS: i also want tho eliminate the AA battery pack<br type="_moz" />

"So what i want to do is update this setup but i want to keep the electonics because they are all working fine"... Sorry but this doesn't make sense to me... You can't update and still use ALL the old stuff!

If you truly want to UPDATE like you said you will need to ditch the ESC and Brushed Motor. Swap to a brushless motor and water-cooled Brushless ESC. You can still use the servo and 27 mhz receiver if you really want to. You can get a cheap water-cooled brushless ESC and motor from hobbyking.com for about $50-$60 for both.

You'll most likely want to run more than a 6 cell nimh on a brushless motor, and in some cases you have to use more than 6 cells nimh. I would suggest getting at least a brand new 7-8 cell nimh pack, go to 2x 7cell NiMh packs or switch to Lipo batteries. (I still run nimh although most will recommend Lipo) Most of the ESC options you will buy will have a BEC that will eliminate the need for a AA battery pack.

What boat is the set-up from? Also If you meant UPDATE using your electronics and just get a new hull I would strongly consider just getting a new boat OR find a newer but used one on http://forums.offshoreelectrics.com/...isplay.php?f=3 - this is the swap shop on Offshoreelectrics.com. Always good stuff for sale there.

Good Luck and welcome to the site.

I agree with the post above.
The rule of thumb, wich in most cases proves to be very accurate, is that the cheapest of brushless motor is still way better than tne most expensive brushed.
So ditch the motor + ESC, thats a minimum.
I also recommend swapping in the battery pack. 6s nimh is just not enough voltage.
You see, power is voltage times amperes.
but ampere causes lots of loss in the wires and ESC, but voltage doesnt.
So you want to get the most of your power through volts. Not amps.
Hence, a higher voltage battery is benefical.
3s lipo (11,1 volts) is the absolute minimum today. I cant think of anything that runs on less than 3 cells lipo.
You also get okay 4 channel 2,4 ghz radio for around 20$ if i remember correctly.
That will save you a lot of heartache with radio interference, old dodgy radio equippment etc.

So thats my recommendation: Swap it all in for some cheap chinese brushless setup.
It doesnt cost a fortune, and the cheapest of brushless, is, as said, way better than the most expensive brushed.

Wel thanks for the fast and goods replies ! Well i was not hoping to keep the battery pack, i just put it in the shema to show where it goes :P And you two confirmed my idea of changing the motor! Changing the ESC is a good idea. I cheked at hobbyking and there alot of good stuff ! But ill need help to find the best ESC and Brushless motor. And i also wanna know, is water cooling necessery? Will a vented area will do the work ? The boat used is in the attached files, its my dad's boat he ran over year and its now mineSo thanks for the advices ill check the topics often to see if anyone have other ideas !

Yep, water cooling is necessary. My experience is that both motor and ESC gets very hot in a boat, despite being run well within its maximum amp limits. Because air circulation is just not enough.
In a plane, both motor and ESC will have fresh inrushing air at high speed, when set up correctly.
Within a boat hull, you will have slow circulating air, and it wont be fresh cool air.
So my advice is definetly get a watercooled ESC, and I would advise a watercooled motor aswell.
I toasted a 150A Turnigy K-Force in my previous boat, running it at 112A.
The same regulator worked fine at 146A in a ducted fan setup previously. Because cooling was so much better in the plane.

-Dual post-

Oh ok i see. I saw on hobbyking that water cooled ESC are mush pricey than the others ones.

So if i understand, i need to take one of these(not the one at 215$ please, im student :P)

And i saw on another web site that outrunners motor are better than the inrunners for boating (i dont know if its true)
<a href="http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7377"><br type="_moz" />
</a><br type="_moz" />

Hi WaveZ

The boat in your picture is a traditional scale-type runabout, not an out-and-out racing boat. What is it you want to do with the boat? - update to more modern electronics but be able to run it at scale-like speeds, or turn it into some kind of racing machine and make it run as fast as you can?

If you look at the modern versions of this boat such as the ProBoat Volere or Runabout, these both use 540/ 550 sized brushed motors today, similar to what you have now.

http://www.proboatmodels.com/Product...ProdID=PRB3050
http://www.proboatmodels.com/Product...ProdID=PRB2600

It looks like you have a 540 sized (36mm diameter) brushed motor in it, so a basic 540 sized brushless motor would be fine and should fit OK. You probably don't want to over-power the boat, it wasn't designed for it - older model boats have fairly flat bottoms to help them plane even with low powered brushed motors, which is not good if you try to make them go too fast.

I suspect you also have adirect drive to a soliddriveshaft connected to a propellor which is completely underneath the hull, with a rudder behind? (can you post a pic?) This will limit the size of propellor you can fit.

Do you have a nicad or Nimh battery charger already, or do you need a charger as well as batteries? If the first, newer NiMh batteries are powerful enough and easy to use. If the second, you could consider lipo batteries but probably not necessary for this style of boat.

For scale-type running (plus a bit more speed) with 6-8 NiMh cells you could consider something like this:

Motor: http://www.hobbyking.com/hobbyking/s...idProduct=6534
ESC: http://www.hobbyking.com/hobbyking/s...idProduct=7377
Water coolingjacket: http://www.offshoreelectrics.com/pro...?prod=gnd-4196
Alternativewater cooling pick-ups (depending on access to inside of hull): http://www.offshoreelectrics.com/pro...od=dh-aqub9520
Radio system: http://www.hobbyking.com/hobbyking/s...dProduct=15141
Servo: http://www.hobbyking.com/hobbyking/s...idProduct=3743


This would give more performance and eliminate the 4AA battery pack. The servoneed to be changed because you have old style Futaba connectors which are not used any more, and a new servo is probably cheaper than an adapter cable.

-yellow-bird

I dont want to turn it into a racing machine but i know i can get some speed with it. I cant upload a pic this week but ill try to get one this weekend. I also have a water cooling pickup and some tubing but its only enters and exits the boat without colling anything(the boat was a nitro powered boat before my dad replace the system without cooling it) and i think i can make a motor cooler myself by rolling metal tubing around it (good idea?). I have a NiMh/NiCD/LiPo charger ( a swallow 2 ac/dc charger ). I like this setup, i think ill get it someday. And if i understand well, i need to change all my stuff for new one :P But that not bad its under 100$. Thanks

I believe inrunners is better suited for boats, because they are much better subjects to water cooling.
Plus, the inherent geometry of an inrunner motor lets it put down more power and efficiency than a similarly sized outrunner.

However: Lady luck has it so that there is a series of cheap outrunners that is supposedly quite good, even compared to expensive ones. I never tried these motors myself in boats, but I got tips from more experienced guys than myself that these motors is good.
The only reason these outrunners is competative in budget racing though, is because there is not to my knowledge any low priced but good inrunners.
However, put a quality inrunner up against a similary sized quality outrunner, and there is no doubt. The inrunner will make mints meat of the outrunner.

These cheap outrunners in question is some Turnigy heli motors.
I tried the 450 in my E-sky Belt-cp helicopter. I didnt notice any significant difference over the stock 450 motor.
I believe the difference shows when you push them hard. Since these ones got cooling fans, I believe they are able to push it farther before running hot. Overheating coils is the weak link for outrunners, so it stands to reason.

http://hobbyking.com/hobbyking/store...idProduct=9258

Ok so the inrunner yellow-bird suggested to me seems to be a good choice ? :P

I purchased one of the same series, and it seems to be good. I havent tried it any application yet, just bench tested it.
I think it can go quite a bit over rated power. I ran mine at rated power for 5 minutes, and it was just warm to the touch. That was without any cooling at all, totally enclosed in my hand.

Oh thats good, with water cooling it'll be perfect ! :P

Ok after reflexion, ill get the setup proposed by yellow-bird, but i need help with my battery choice. I want a lipo that fits the setup, i have a Swallow 2 AC/DC charger that take lipo's. (I also wanna know how to charge/discharge/store these babies cause i never had lipo's before)<div>
</div><div>PS: srry for the double and these are the specs of the charger</div><div>http://www.modelflight.com.au/rc_mod.../swallow_2.htm</div>

How the batteries should be cherged is ususally printed on them, if it deviates from the general rule.
The general rule is charging them at 1C. 1C means that you should charge the battery with a current answering to the batterys specified capacity in mAH, divided by mH (1000).


Practicalltly, it means that a 1000 mAH battery should be charged at 1 A, a 3300mAH battery at 3.3 A, etc.
That is a charge rate of 1C. Some batteries can be charged faster, and this will be specified on the battery. If its for example 5C, then you just multiply the 1C Charge figure with 5.
Wich means, 5A for the 1000mAH battery, at 5C.

Hmm ok well i tried to look on hobby king for batteries that fits the requirements and i found these two ones:<div></div><div>http://hobbyking.com/hobbyking/store...dProduct=11946</div><div>http://hobbyking.com/hobbyking/store...dProduct=11919</div><div></div><div>I want to know if my tought where good in this choice of battery? And, for example, if i take the first one wich is 2.65 A on 3 cells i should charge it at 7,95 A? That seems really high for a battery</div>

No, you should still charge them at 2.65A. Because the cells is in series, and each cell must not be charged any harder than 1C, unless otherwise is specified.
In series, all cells will have a current equally high as the main current in to the battery.
If you put packs in parallel however, then you can multiply the charge current as you did.

Those batteries seems ok for the suggested setup at first glance, not knowing more details about your prop, drive type or hull.
3s for a 3200Kv is a good place to start with for a smaller, high reving boat. Unless your propeller is ridicilously large, I think you will be within the safe limits for amp draw. The rule of thumb (for a little larger boats) is that the prop should spin at 30 000 rpm.
A 3200 Kv motor with a 3S battery will spin at approx 28000 rpm, under load, and 35000 at idle. So Ithink that thats a good place to start with.

Ohh ok now i understand ! The setup isnt for great speed so if you think the setup will be ok for the boat ill order it in a couple of week, winter season anyway :P Thx alot, if anyone have any tips to add its always a good thing

Electrically, I think this setup is good.
Mechanically, you have to measure because I dont know your boat.
Does the motor fit into your motor mounts? Is the axle diameter of the motor the same as the old, so your connectors will fit? Is there enough place to put the new, probably larger batteries, and the new, probably larger ESC?
Check that out first, or you might get a surprise. All sizes of the new stuff is in the product description in the links that yellowbird sent you. So measure the space in your hull, and compare =)

Most new ESCs from hobbyking is sold without any connectors.
Most new batteries from hobbyking is sold with XT60 female connector only.
Turnigy inrunner motors of that series is sold with 4mm bullet connectors, usually both male and female. But sometimes with only male.

Make sure you got the connectors you need, or make sure to order them at the same time.
basic soldering skills, and gear, is needed.

I think i have enought room to place all in it because it was a nitro boat back in the days, so place for the motor, exhaust, gaz tank, servos...I think a electric setup will fit perfecty, and yeah i forgot to take the motor axle diameter. But i might need some help with the connectors :S

Bullet connectors on the motor side is all good, so you dont have to do much about them, other than solder their female counterparts to the ESC.
On the battery side, you might want to pick a connector to be your general purpose connector, or universal connector if you like.
If you got one type of your connector on all your models and batteries, swapping in between, and charging them, becomes a much simpler business. mine standard connector is the dreaded deans. If i were to pick one today, XT60 would been a good candidate. So if you havent picked any universal connector already, Just sticking with the XT60 that the battery comes with is fine.
But its delivered without a male XT60 plug, so you need to order one. As the name implies, XT60 is good up to 60A continous draw. So if you plan on any later models with higher amp draw, you might just aswell choose a more powerful plug right away.

Edit: By the way, do you have a wattmeter already? If not, place that on the order aswell. Its not very expensive, but it helps you a lot when trying to find a descent prop size. You definetly want to get a reading on watts and amps on first run. In case the prop is too heavy, that can be disasterous.

I put regular tamiya connectors on my charger/batteries cause i have a tamiya drifter, so ill put the same thing here. i might have a wattmeter some where ill chek that too. And what can be so disasterous with the prop weight?

PS:i uploaded a picture of the boat with the prop on the shaft on the right side(dunno if it helps)

Im not familiar with the Tamiya connectors, but do ensure they cna handle the current you will be facing (wich you find with your wattmeter).
A to big propeller is disastrous because it can overload motor and ESC. And ESC is ususally the first to give in, and it gives in faster than you might think if the prop is way too big.
So keep an eye on the amp draw on your first run

Hmm ok so i might try to make an adapter on my charger to XT60 and put that on my setup, better not take a chance..As i said earlyer, its winter season so ill get the setup, take he amp draw(wich i need to find out how to do it lol)  and order the prop after, these tings are low priced anyway(dont want to double pay the shipping tho...) Ill try to make a graphical setup tomorrow to make sure i understood all good :P Ill post it as soon as i made it.

So thats what i think all is supposed to be. Correct me if not.