LiPo + brushed 550 motor help

[ScarabChris]

You guys know I built the scale Scarab Sport with twin EP1 outboards.

Here's my problem. The boat runs so good on the 3000 mAh LiPos but the motors aren't going to last using these batteries. So I got some 8.4 volt NiMH 7 cell batteries. The boat is slower on these batteries because of less power and a lot more weight.

So my question is. What motors will be a direct bolt on to replace stock 550s but can handle the 12+ volts of the LiPos?

The stock 550s emit a pretty bad smell after a short run on the LiPos.

[JMSCARD]

You guys know I built the scale Scarab Sport with twin EP1 outboards.

Here's my problem. The boat runs so good on the 3000 mAh LiPos but the motors aren't going to last using these batteries. So I got some 8.4 volt NiMH 7 cell batteries. The boat is slower on these batteries because of less power and a lot more weight.

So my question is. What motors will be a direct bolt on to replace stock 550s but can handle the 12+ volts of the LiPos?

The stock 550s emit a pretty bad smell after a short run on the LiPos.

I think I am correct in thinking the 550 brushed motors share the same bolt pattern as a 540 motor.... if so I would go with a couple 8xl's and a couple 120 amp turnigy marine esc's or Swordfish 120's here at OSE... ?? would give you even more speed though... not that you care about that :)

[ScarabChris]

These ProBoat ESCs won't work? They barely get hot even when running the Lipos.

http://www.offshoreelectrics.com/proddetail.php?prod=dh-prb2314

[ScarabChris]

I see, that 8XL is a brushless.

Trying to stay with a brushed motor for now. Not ready to rebuild the entire electrical system. I'm just looking for a simple motor swap if possible.

If not I'll keep buying the stock 550s from Tower at 12 bucks each.

[JMSCARD]

I see, that 8XL is a brushless.

Trying to stay with a brushed motor for now. Not ready to rebuild the entire electrical system. I'm just looking for a simple motor swap if possible.

If not I'll keep buying the stock 550s from Tower at 12 bucks each.

I see.... Id keep buying the 550's.... lol.... actually SV27 motors (brushless) would work for you application better then the 8xl's.... the 8xl's would be over the top.... I hear ya though... the stock brushed motors are cheap!!!

[ScarabChris]

OK after seeing this twin EP1 boat I think I want brushless...

http://www.youtube.com/watch?v=V83uEx9Rc18&feature=related

Help me order the correct motors and ESCs.

I want reverse.

[JMSCARD]

OK after seeing this twin EP1 boat I think I want brushless...

http://www.youtube.com/watch?v=V83uEx9Rc18&feature=related

Help me order the correct motors and ESCs.

I want reverse.

will need to do some research to see which motors will fit under the EP-1's "hood".... I think some cheap turnigy esc's will be your best bet.... like turnigy marine 120's ... they have reverse I bleieve and will be good for may uses... $49.95 each... can't beat it.... and some Blackjack or sv27 motors sound like a good combo... just would wanna make sure they work in the ep1.... you can run 3s for faster then scale speed and down the road if you want to run 4s you can really go.... 5s.... and look out :)

[ScarabChris]

Here is how he describes what he has. Clearly they fit under the cowling. I'mm fine using the 3S 3000 mAh 11.1 volt LiPos I have. Also, can the brushless motors counter rotate?

"netik racing blackjack twin aquacraft outboards 9turn hobbywing ezrun 30c 5200mah 7.4 volt"

"hey ! thease are just the hobbywing car brushless systems from ebay! there are two types 13turn & 9turn both with a 35 amp speedy! they are both great just keep the grease up to all parts to keep the salt from killing it all dry it all out when you get home from boating .. have fun"

[JMSCARD]

Here is how he describes what he has. Clearly they fit under the cowling. I'mm fine using the 3S 3000 mAh 11.1 volt LiPos I have. Also, can the brushless motors counter rotate?

"netik racing blackjack twin aquacraft outboards 9turn hobbywing ezrun 30c 5200mah 7.4 volt"

"hey ! thease are just the hobbywing car brushless systems from ebay! there are two types 13turn & 9turn both with a 35 amp speedy! they are both great just keep the grease up to all parts to keep the salt from killing it all dry it all out when you get home from boating .. have fun"

I was searching around and noticing you don't want to power the ep1's to crazy as the gears are the "weak link" so that system he is using maybe a good setup so you don't go overboard.... you will want to make sure the motor shaft is the same size too so you won't have to buy another flex collet or make any big changes on that end as well... if you put ep1 into the search engine here on OSE you will find alot of info to "sift" through...

[ScarabChris]

Yeah the gears are the weak link. But I am trying something different. The way these motors come they just have grease in the gear case. That doesn't work very well because the grease just gets moved out of the way of the gears.

I'm going to do it like a real boat lower unit. With the gears immersed high grade gear oil. That should make the gears last much longer.

No I don't want the boat to be "super fast" but close to what the guy in that video has will make me happy. My biggest problem is that these 550 motors are just junk if you try to push them at all. I already smoked one on the Lipos and another is on its way out.

What I want is a little more speed but for it to be reliable.

I have two extra motor housings that I'm working right now so the gears will be in an oil bath.

I am just an idiot when it comes to this electric thing. I guess I first need to find the dimensions, shaft size and bolt pattern of the stock 550s and go from there. I still won't know what motors to select, I see there are so many for so many different applications.

I'll need guidance on this one.

[ScarabChris]

OK after some quick research....

The stock 550 motors specs are as follows....

Diameter of can = 37 mm
Shaft thickness = 3 mm
Hight of motor can from mounting point = 57mm
Length of shaft from mounting point = 20 mm
Distance between mounting holes = 25 mm

So............

[ScarabChris]

I think I am correct in thinking the 550 brushed motors share the same bolt pattern as a 540 motor.... if so I would go with a couple 8xl's and a couple 120 amp turnigy marine esc's or Swordfish 120's here at OSE... ?? would give you even more speed though... not that you care about that :)

I think I will go this route. I am looking at these motors....

http://www.offshoreelectrics.com/proddetail.php?prod=fei-540S&cat=116

But can someone tell me what all these numbers mean? I know I will need the 1/8" shaft as its closer to the 3mm size of the 550.

I pretty sure the number in the (#) is the quantity in stock. ut how many RPMs do I need? And what does the rest mean? Just want to get the right ones.


feigao 540S: 540 6S 6,192 RPM/Volt 1/8" Shaft (6)
540 7S 5,196 RPM/Volt 1/8" Shaft (3)
540 8S 4,761 RPM/Volt 1/8" Shaft (1)
540 9S 4,332 RPM/Volt 1/8" Shaft (2)
540 10S 3,783 RPM/Volt 1/8" Shaft (3)
540 12S 3,180 RPM/Volt 1/8" Shaft (12)
540 16S 2,400 RPM/Volt 1/8" Shaft (2)
540 4S 8,450 RPM/Volt 5mm Shaft (2)
540 5S 7,289 RPM/Volt 5mm Shaft (3)
540 6S 6,192 RPM/Volt 5mm Shaft (4)
540 7S 5,196 RPM/Volt 5mm Shaft (3)
540 8S 4,761 RPM/Volt 5mm Shaft (5)
540 10S 3,783 RPM/Volt 5mm Shaft (0)
540 12S 3,180 RPM/Volt 5mm Shaft (1)

And this ESC....http://www.offshoreelectrics.com/pro...=hef-sword-120

But does it have reverse?

[befu]

First things first.

Take a look at what you are running right now, the performance you are getting and were you want to end up.

Speed wise, how much do you want to increase it?
Power: When running NiMh, what is the size of the pack and how long does a full charge last? You need to figure out how much amperage you are pulling. From that, you can estimate the power the motors are consuming and putting out.
How fast are the props spinning also. If you pull a motor and have a prop tach, you can estimate the KV of the current motor.

Then you start doing math. You estimate the rpm of your motor and how fast the props are spinning. You guess at how much faster you want to spin them, then you decide what lipo you are running (you have one already). From that, you pick a new KV (rpm/volt). Once you have that, you can select a motor to match your guess at wattage.

first thing, I would try to find out what wattage you are running, that will give you a starting point. What is the amp rating of your current esc? Is there one or two? those motors on the cat were being sold with 35 amp ESC's, so you might not need a 120 amps ESC.

need some basics before you start buying big dollar parts.

Brian

[Make-a-Wake]

OK Chris, so you're taking the brushless plunge afterall! If you go with the Feigao 540s you want the 16s for 3s, you dont need huge rpms, and it comes with the 1/8" shaft. The 16s will give you around 28,000 rpms unloaded and around 23,000 in the water. That should give you a nice performance boost and they are a direct bolt in to your outboards. The most crucial part is the length(or height in this case), they will fit nicely under the cowls. The 120a speedos seem like overkill to me.......but you cant go wrong with a bunch of room there.

[befu]

Just saw this in the comments section under that video you posted of the twin cat:

hey ! thease are just the hobbywing car brushless systems from ebay! there are two types 13turn & 9turn both with a 35 amp speedy! they are both great just keep the grease up to all parts to keep the salt from killing it all dry it all out when you get home from boating .. have fun

sounds like he is running that on 35 amps esc's. Might not go that small, but watch how much power you put on those gears.

Have you done any searching on the web to see what brushless motors others are running on these outboards? somebody had to do something and write about it.