ESC Melting

[bleoo]

Hey guys

I bought the MRC F-1 it's a nice boat, and it goes like snot. The problem I have is that my Proboat ESC is melting the epoxy and spitting out molten solder
The esc is able of 15 turn modified 540 motor, 6 to 10 cells and 40amps constant. I am running stock prop a 15turn double speed gem motor, water cooling on the motor. Yesturday I ran my boat for the life of a batt (3300 nmhi)
and noticed after the run the ESC was melting, but it was still running fine. So tonight I went to the shop and replaced the ESC with another one, I went back to the pond and ran the boat without it's top to allow the ESC some air again I ran the life of the batt, it ran fast and problem free until I brought it in to ispect the ESC. It started to melt.

Do I need another ESC that can take my setup, if so what would you guys recomend?

Why dont companies state what their ESC's can really take, What I'm trying to say is I went according to their specs I'm not running a big boat, I'm runnig
a moded 15 turn motor, and a stock prop. They should assume poeple would run stock props with moded motors. Why is it melting??????

Thanks
Bleoo

[n.h.schmidt]

Hi
Several things are in play here. First ,the makers of many esc's tend to be way off on just how much power they can handle. Next you have too large of a boat for this motor . Unless you add a gear drive ,you will soon burn it up. You need to experiment with different props. The geardrive will likely help the most here. A outboard can be converted to gear drive and work out very nicely. n.h.schmidt

[Fluid]

Your are exceeding the capacity of a cheap ESC. The stock prop is designed for a mild motor - add a relatively hot motor and the motor will draw a lot of amps, too much for the ESC to handle. Another problem is running the boat until the 3300 cells dump - this is not right! The entry level RTR boats are designed for cheap packs of 1500 to 1800 cells, not for high performance 3300s. If you hop the boat up you will not be able to use all the capacity of the battery without overheating. Oval racers use 3300 cells, but they only run them for 60-90 seconds tops, never until they dump.

If you want to use the current motor you'll have to use a smaller prop, and only run for 90 seconds - use a stopwatch. A better ESC will also be called for. This hull will perform okay on a 15-turn motor, but you have to be conservative on props and cell count and it has to be set up right. Are you running 6 or 7 cells?

[bleoo]

Thanks for the reply
I am running 6 cells, what would you recomend I use as a speed controler?
I will try a smaller prop 30mm to 35mm. I think I might try a 17 turn double or my 19 turn trinity mortors to see what happens.

Bleoo

[Doc]

Bleoo,
Whichever motor you use, do a stall test. Find our what the maximum current draw is. Select your ESC accordingly. Air flow across the ESC's heat sinks always helps, so does water cooling for those that can be done that way. But if the current rating of the ESC isn't at least the maximum that the motor draws, it'll get hot enough to 'melt'.
- 'Doc

PS - Never hurts to have a little 'extra' as far as the ESC ratings go...

[MOTOboat]

Hi Bleoo,

I have the Same boat but with a NOVAK XR-S ESC. It is also a 4 -7 Cell 40 amp ESC. It in in the radio box so I don';t have it water proofed.

Stock I have ran a NiCAD 2000, NiMH 2000 and a NiMH 3300 consecutavly and while th emotor got warm I could still hold it. I was pretty happy, well for a day or two. ;)

I purchased a 15 Double turn motor (540) to replace the stock motor. The current stock motor with 6 3300 cells work well and gets warm bit, But it is kind of slow in my opinion. IT work very well for the money

I want to upgrade the motor but have been holding back because I wasn't sure if I would need a larger prop. Do ou have any idea what the stock Prop is?

Beiong a newbee peak current at stall how does one do that. How do I know what currrnet he motor will take beofre over heating.

MOTOboat
Could I email you so we could discuss the setup of these boats. I am very new to R/C boating

[bleoo]

Hey guy's I went out last night to run the boat with a 19 turn motor.
everything was good. the speed controler was warm, but O.K.
When I was running with the 15 turn double motor the motor never got hot at all but like I said the ESC was melting. I think I will try my luck with a 17 turn double motor (speed gem pro) I will cut vents to allow air flow and I will try to water cool the ESC to see what happens. I will still be replaceing the Proboat ESC with a better one. I have seen so many threads about not to use car ESC and to use Car ESC it gets confusing. I have a Novak Super Rooster with no motor limit I would think this would be one of the best ESCs to use except it is not waterproof.

MOTOboat you can E-Mail me if you would like but I am very new to R/C boats
I don't know how to do a stall test. I think our stock prop is 40mm, I'm not even sure really on how to measure props. sorry I'm not much help. but feel free to E-mail me we might be able to help each other.

Hey Doc.
Could you let us know how to do a stall test. anything I can learn would be great.

Thanks
Bleoo

[Fluid]

The biggest problem with car ESCs is that they are not waterproof. If you can keep them dry they can work fine IF they have the current capacity required. IMO a 40 amp controller is barely adequate for a 27-turn stock motor. For a real race setup you will want a controller capable of at least 60 amps or more; many car controllers are over-rated and while they say they handle 100 amps, in reality they will not in a boat. The right type of controller will not over heat and will supply more power to the motor for more speed. The best boat ESCs for brushed motors are from http://www.rc-hydros.com

The motor didn't get hot because it is exposed to cooling air outside the boat. The ESC heated up because it is a low amp version and has excessive resistance, which shows itself as too much heat.

I wouldn't recommend that you perform a true stall test. This can generate a lot of current and heat, and can damage your motor if you are not familiar with the procedure. You don't need to do this anyway - I don't know one national-level FE racer who ever does it, in fact I don't know anyone who does it. The easiest way to go is to just get a marine controller like the rc-hydros with at least a 60 amp rating. Trying to run more than 60 amps through an 05 car motor will wear it out quickly anyway. Just choose the right prop and get the boat set up to run freely and you'll be alright.

[Pagemaster]

I think our stock prop is 40mm, I'm not even sure really on how to measure props. sorry I'm not much help.

Thanks
Bleoo

Its easy to find measure the stock width, but use a ruler and go measure from tip to tip. Most props are have a pitch of 1.2 or 1.4. Seems most of the rtr companies are running 1.4 pitch, some of the older Kyosho stuff was as big as 1.6 pitch.


Fluid is correct about the esc's, it may seem more expensive to buy a quality control but it will last for years. I still have esc's from 4 years ago.

The proboat esc is good for a stock type setup. My son runs one in his Riptide and it runs great. Its never hot unless we run more 7 or more cells, but still not hot enough to melt.

[bleoo]

Thanks alot guys I will look into getting a RC Hydro ESC I will keep you all posted on how things turn out. I will try to get some pics up of the boat, maybe
even a vid clip.

Bleoo