MHZ 54" catamaran help needed

[Toberi]

Had plenty different rc boat up until today. No pro stuff at all but having a proper interested. Setting up a "winter project" by puttning together a complete boat by myself for the first time. Bought a 54" mystic c5000 catamaran hull to start with. Now I'm investigating what motors i will use. I calculated i will need 2 pcs 300A ecs and MHZ is recommending me to buy their motors Scorpion 5035 760KV-7,4KW. Are really outrunners a good choice on this boat I'm building? I would need some help from some more experienced people please...

/Tobbe

[jkflow]

Motor really depends on what you want to run, how many cells 6S, 8, 12S?
Sounds like 12S with that kV rating. Any ~700kV rated motor will be fine.
What is your main goal? SAW type or just for fun?

I'd check this site for motors and ESC options, https://www.offshoreelectrics.com/
or just click on 'store' above

[Toberi]

Hi jkflow! Appreciate your effort in my struggeling... Naa I just like playing around, it's just for fun. I love torque more than top speed even in the same time it's cool to make a real brutal top speed rip. Yes my plan was 10s to 12s. I just bought ZTW SEAL BL ESC 300A that can run take 14s. The Scorpion outrunners that MHZ recommended me can do 12s tops. My tiny experience tells me the outrunners would be ok for the torque and also get me enough top speed. Several friends had some bad experience with cooling on the their outrunners, but that is quite long time ago. Maybe there is better stuff on the market nowadays? My main concern is that I can't find a single person or a Youtube video showing this kind of boat with outrunners. Just want someone to hold my hand before buying the motors hahaha. Feel like a complete newbie, no one to ask...

[Panther6834]

Still a newb where RC boat building is concerned (have built PLENTY of land vehicles)...but, personally, I stay away from out runners on everything except crawlers & drones. Cooling motors in a boat is MUCH easier (and better) with (traditional) inrunners.


~ More peace, love, laughter, & kindness would make the world a MUCH better place

[Toberi]

Hmmm this is exactly what I was thinking. I'll stay away from the outrunners in boats...
Tnx for fast reply!!

[fweasel]

TP 5660 888kV, ZTW 300A V1 ESC, 10-12S is a good setup for a fast MHZ 138.

[Bande1]

ose had a discount sss 56123 500kv for $159. its rated for 9000w continuous. that'd be my choice. run 3 blade gas props on 10s-12s like a 2517 or so. big motor also helps balance the hull from a 12s pack. flier 400A esc.

[Bande1]

heres the motor

https://www.offshoreelectrics.com/pr...s-56123-v1-500

[Toberi]

Great input both of you, now I have something to dig into!

[vvviivvv]

Are you building a twin or a single? A 56123 is a huge motor and has no place in a mystic 138, 12s is also going to be a fair squeeze in a 138… if running 12s/ motor…

Motors 2/3 the size of a 56123 can push a 138 hull to 120+mph.

[Toberi]

I bought 2 pcs ZTW SEAL BL ESC 300A, supposed to end up a twin. You still think TP 5660 888kV can be a good choice? I'm more in to aggressivity than absolute super top speed, but of course I want a real descent top speed...

[fweasel]

The TP5660 888kV in a 138 on 12S is a known 110+ setup with an aggressive prop. Dropping down in voltage will tame the speeds. 56mm motors will have plenty of torque for hole shots and rapid acceleration of that's what you mean by "aggressivity". Be sure to use 1/4" flex cables and quality collets. The MHZ mystic hulls handle like wet dish rags until they're on plane and moving on top of the water, so a build like this will be best suited for longer straight passes, weather you're breaking the sound barrier or not.

[Toberi]

Thanks fweasel for your input! Hahaha yes aggressivity meaning hole shots etc, in lack of a better word. Wet dish rag...
Sure I can find a nice 56 mm inrunner!

[Panther6834]

The MHZ mystic hulls handle like wet dish rags until they're on plane and moving on top of the water, so a build like this will be best suited for longer straight passes...

Not trying to hijack Toberi's thread...so, of you prefer to answer via PM, go ahead (tho, I suspect, others reason this thread, and my question, might be 'interested').

If the MHZ Mystic is best suited for SAW, what large-scale cat hulls would you suggest/recommend for a twin "just for fun" pleasure/bashing boat? In other words, something with a strong/sturdy enough hull that can handle higher speeds (tho, it would never be used for top-end speeds), but is also designed to be highly maneuverable (ie. turns in both directions equally well, whether the turn is 'gradual', or somewhat (but not necessarily 'extremely') sharp?


~ More peace, love, laughter, & kindness would make the world a MUCH better place

[Toberi]

Hmm do I hijack my own thread by also asking? Good question... I live by the sea, not a lake. The small experience I have is the catamaran hulls is way better due to wind and waves, good stability. fweasel have a point on the instability on the flying part when it's actually in the air, I also had some experience on that. May it rest in peace...