Minimun amp rating of and esc for 2s & CMS7700

[lincpimp]

Originally Posted by 83gt

Cooling won't be so much of an issue, and load should be relatively low compared to 1/10th off-road.

J.

I have to disagree, boat have very high amp requirements, as the speed goes up, so does the load. I would not be suprised for a 7700 on 2s in that boat to pull 80amps or more, each. I have a supervee, and a few other boats. The sv27 can produce almost 700watts, so on 14v (4s lipo under load) that is 50amps. Of couse, motors running half the voltage will have to pull twice the amps... The only way boats get by is due to water cooling, even a feigao will run cool in a boat with a decent water cooling system. It will still not be effecient, but will run cool.

Originally Posted by Gee

My bad. I'll will be more up front in my questions from now on. I just didn't want to get all the responses telling me the othe motors I should use, or scrap the whole thought and get the SB27. But then again this is RCM. That don't happen here. No matter how whacked out our projects can get. We're all supportive. Family, gotta love em. Thanks for the help.

So it sounds like a 60amp would be a minimum to try. Any thoughts on the type of esc I linked to?

I would run a pair of 80 amp escs (water cooled) with the 7700 motors. And try to gear them down as much as possible smaller pinions) , as they will run quite a bit faster than the stock brushed motors. You should most likely step up the props a bit, but testing on the stock props should be fine. I have no idea how stable the hull is on the villian, 40mph may be all it can handle.

I got my sv27 up to 44mph, running stock motor and esc with a pair of 3600 12c 2s lipos in series. The batteries were limiting the boat. It was fun, the only thing in the water was half og the prop, and the last little bit of the trim tabs. We could see daylight under the hull...

[lincpimp]

Originally Posted by hemiblas

I'm a big fan of my villain since the last time I took my supervee to the lake the water was to rough to get on the plane.

Buy yourself an octura x642 prop, polish and balance it, and enjoy. Adds about 4-8mph and greatly increase the speed out the hole. Use good lipos though... nimhs will not cut it in this boat. No way nimhs can produce 60+ amps continuous...

[Gee]

Thanks hemiblas. That was a helpful post. I had no idea what the amp draw of the motors would be. For that mater any motors. I opened up the Medusa instruction sheet today and behold they have a table in it with some info concerning the amp draw of their motors. That table gave me some good references to go from also. The highest KV motor 4800 was list as 97a cont. That helped me put things into perspective also. I've seen that table before (RCM store for 1) but didn't understand the abreviations that were used in the header. Even if I don't attempt this with the 7700's I've once again learned somethjing new and useful. Thanks for helping me figure things out RCMers

[hemiblas]

I like playing around with crazy combinations like that atoo and think it would be a nice build, but people (Me included) have smoked many a speed controller doing stuff like this. I understand why you didnt post what you were trying to do originally. Every time someone with a villain get on the forums its always the same comments about limitation on the hull etc etc. Realistically if all you want is 35mph or under it makes a great boat in rough waters and then you get the extra speed to boot.



Ideally to make this work you would want to know the rpm of the titans and then regear so its up 10 or 20 percent if thats even at all possible. Even then an 80A speed control would still be a minimum I would use, with watercooling.

FYI I just bought a pair of the great planes 600 motors for my villain. It was either that or 2 brushless motors with speed controls. To keep things in perspective the supervee motors are like 1900 rpm/ volt and its a 45 amp speed control on that one.

[lincpimp]

Originally Posted by hemiblas

I like playing around with crazy combinations like that atoo and think it would be a nice build, but people (Me included) have smoked many a speed controller doing stuff like this. I understand why you didnt post what you were trying to do originally. Every time someone with a villain get on the forums its always the same comments about limitation on the hull etc etc. Realistically if all you want is 35mph or under it makes a great boat in rough waters and then you get the extra speed to boot.



Ideally to make this work you would want to know the rpm of the titans and then regear so its up 10 or 20 percent if thats even at all possible. Even then an 80A speed control would still be a minimum I would use, with watercooling.

FYI I just bought a pair of the great planes 600 motors for my villain. It was either that or 2 brushless motors with speed controls. To keep things in perspective the supervee motors are like 1900 rpm/ volt and its a 45 amp speed control on that one.

I bet a pir of sv27 motors and speed controls would really wake up a villian, on 4s. IIRC the octura m447 props work well on the villians, just havve to buy a normal and a counterrotating. Steven at OSE sells the whole thing as a kit, with the upgrade stub shafts to fit 3/16 props...

[hemiblas]

Sweet, Yeah I have thought about a couple of sv27s, 45 amp speed controllers and throwing it all into the villain with a couple of 4S lipos, but it would be extreme overkill. The villain couldnt handle one of those motors, but 2 would just be uncontrollable even at half throttle.