MHZ Mystic 1380mm build

[Alfa Spirit]

That is what I told you before, don' t be afraid to run high RPM.
You must have 35000 RPM unload for a good acceleration and high speed, especialy with a catamaran. And don' t forget that the motors you choosed are heavy.
Forget 10S batteries and go for 12S, but I think it won' t be enough...
On my 50" FOUNTAIN P1 the setup will be 4092 - 930kV motors and 10S for each one, The motors are on the way, the weight of one motor is 500 grammes.

If you order the SKYRC Proteus X520 The setup can be ok with 3D wiring - 1280kV and 8S batteries, 37888 RPM unload.I hope this is what you order... not the X524? So why 10S?

[MrUnlimited]

I have been racing 1/8 hydroplanes for many years: our gas engines and nitro engines turn only 20k-25k rpm. Not fast huh? These boats run over 85mph! Why? Because of the pitch on the prop. It is not like the more rpm the faster you go like rc cars but we turn a LOADED 10k-11k rpm on the prop and play with the pitch. By using lifting props we achieve high speeds. So 730KV on 10s gives me more the 30k rpm unloaded with the right prop it gives me enough speed. A full lipo cell delivers over 4 volts, so 10s delivers over 40volts

[MrUnlimited]

Didn't make any cuts before gluing. I just glued them in, and then cut to size after I measured the distance. I used a flex cable to measure. Feed it up till it hits the motor shaft, then apply some tape on the prop end and use that as a guide.

Kent I run square drives L&R in my mhz138. That is why I have to cut them first but I am gonna look where the cg and the dtermine how much I have to cut.

[drwayne]

I have been racing 1/8 hydroplanes for many years: our gas engines and nitro engines turn only 20k-25k rpm. Not fast huh? These boats run over 85mph! Why? Because of the pitch on the prop. It is not like the more rpm the faster you go like rc cars but we turn a LOADED 10k-11k rpm on the prop and play with the pitch. By using lifting props we achieve high speeds. So 730KV on 10s gives me more the 30k rpm unloaded with the right prop it gives me enough speed. A full lipo cell delivers over 4 volts, so 10s delivers over 40volts

Hi. I run twins... 12S to 730Kv, after batt/esc/motor efficiency losses expect <80% down the shaft.
Higher voltage equates lower amp draw....high amps will cause grief quicker than high voltage to the electrics
I note here that US have 10S voltage limit for racing.

Kent I run square drives L&R in my mhz138. That is why I have to cut them first but I am gonna look where the cg and the dtermine how much I have to cut.

You've lost many forum experts now.... sq drive ? haha
High rpm sq drives get induced vibration that's "hard to shake".
Rarely seen sq collets for FE motors at OSE . the threaded claw / grubscrew type are all the norm.. relocate thrust face from stinger to eng mount...
You would most certainly need extra buttressing at the stinger faceplate for a sq drive setup.
regs
DocW

[MrUnlimited]

Wayne,

I drive in my other boats squares without problems, also my fellow competition boaters swear by them and they run their boats on National, European and Worlds Championships.

[nata2run]

Ok, wow. Ditch the square drives and invest in a high quality MBP collet. You will never regret it. Also you ca t load up an electric motor like a gas. You can load up a gas motor till it stalls. You do that an electric and it will light on fire!!!! An electric motor don't know it's limit, it will simply go on pulling till it burns. That's why we take some pressure off with smaller props. But smaller props need more rpm. So there it is in a nutshell.

[nata2run]

For this size cat a 457 is very common, how ever for very serious setups you can run bigger but also spin them faster. 457 in mid 30k is a good sport setup. To go past 80mph you'll have to be late 30k. 100mph can be achieved in the 40's. I have spun my 457 cut to 52 @ 43k

[drwayne]

Wayne,

I drive in my other boats squares without problems, also my fellow competition boaters swear by them and they run their boats on National, European and Worlds Championships.

Certainly, I qualified my comment by "Rarely seen sq collets for FE motors at OSE".
I used sq for 28+ yrs in nitro ( never ran gas )

For this size cat a 457 is very common, how ever for very serious setups you can run bigger but also spin them faster. 457 in mid 30k is a good sport setup. To go past 80mph you'll have to be late 30k. 100mph can be achieved in the 40's. I have spun my 457 cut to 52 @ 43k

Are you serious ?

I thought this was a serious thread .

sorry.

[jkr]

Question:
A pair of 1527 850kv 12s?
Do you thing it could go fast?

[nata2run]

Question:
A pair of 1527 850kv 12s?
Do you thing it could go fast?

Yeah not bad speed, but super fast you might want a motor that's really up to it. Like a 56 or lehner 3040

[nata2run]

Certainly, I qualified my comment by "Rarely seen sq collets for FE motors at OSE".
I used sq for 28+ yrs in nitro ( never ran gas )



Are you serious ?

I thought this was a serious thread .

sorry.

Yes I'm serious, please remind me again how it works in a 54" hull

[jkr]

My thought
Twin 12s 1527 90+
I thing it is possible also 1kg lighter.

[jkr]

I know lehners but i don't really like them.

[nata2run]

My thought
Twin 12s 1527 90+
I thing it is possible also 1kg lighter.

Yes most likely possible, in a 54" could be risky.

[Chrisg81983]

Kent said:::::
For this size cat a 457 is very common, how ever for very serious setups you can run bigger but also spin them faster. 457 in mid 30k is a good sport setup. To go past 80mph you'll have to be late 30k. 100mph can be achieved in the 40's. I have spun my 457 cut to 52 @ 43k

You said:
Are you serious ?I thought this was a serious thread .sorry.[/QUOTE]

DOC WHAT SO HARD TO TAKE SERIOUS ? How come you are always taking shots at kent ? from what I see he is very knowledgeable, and how I see it he has a faster or actually several faster boats. So how I see it you should be listening to him rite ? Please don't take this personal but I just been seeing you kinda be a **** to him in many posts so I was just wondering what the deal is. You are both smart men lets keep it at that. Thanks

[drwayne]

I see it you should be listening to him rite ?

you're both comedians !

[MrUnlimited]

Certainly, I qualified my comment by "Rarely seen sq collets for FE motors at OSE".
I used sq for 28+ yrs in nitro ( never ran gas )



Are you serious ?

I thought this was a serious thread .

sorry.

So tell me Wayne, why is a wellknown company like MHZ selling them for their own boats?

[nata2run]

I like the idea of the normal type collets. Specially the MBP ones. They are so easy to get the shaft in and out. I use to hate taking out my shafts coz I never knew if it would get stuck or anything. With these its so easy!!!! And the have a fantastic grip. What flex size are you running? I'm only running 5mm, but I find it strong as!

[drwayne]

So tell me Wayne, why is a wellknown company like MHZ selling them for their own boats?

MHZ cater a market higher than the rtr generics.

Kent knows round is better because he was told so by it's GmbH promoter ... and in his experience it works well.

Read the post again.. Ive not offered one as better the other, just a statement of fact.

[drwayne]

DOC WHAT SO HARD TO TAKE SERIOUS ? How come you are always taking shots at kent ? from what I see he is very knowledgeable, and how I see it he has a faster or actually several faster boats. So how I see it you should be listening to him rite ? Please don't take this personal but I just been seeing you kinda be a **** to him in many posts so I was just wondering what the deal is. You are both smart men lets keep it at that. Thanks

sent Pm.
read and assimilate.

[ManuelW]

To get some statements and facts in a weird conversation:

-Kent is right, X457 is a good choice for a 54" cat with average weight and it makes sense to chose a setup suiting to run with this prop.

-For the high-rpm fraction:
HPR 135
2x LMT 3040/9 with just 1167kv
2x 8S 45C
2x X457
--> 98mph

And thats not calculated or estimated, but I've built and driven it! Boat had around 9kg RTR and performance was pretty agressive.

-square type couplers also can work for higher rpm's when the quality is good and the system installed well. JetCat delivers their turbines only with square type couplers and the Hydroplane version can spin up to 35.000rpm. Thrust me, there is still enough security.
EDIT: I also got a set of square type couplers from MHZ for the MHZ Mystic 185 I'm building. Sent them straight back as well as the RC box they sold for an electric build

regards,
Manuel

[nata2run]

"Kent knows round is better because he was told so by it's GmbH promoter ... and in his experience it works well"

Kent also has square, but still likes round better, are you though?
Why don't you build this boat, and share your experience with others. That's simply what I'm doing. Not because I was told.

[Chrisg81983]

I have ran square flexes many times at a pretty high rpm's in electric systems. I must say they worked fine, and I really never had a problem with them plus I achieved pretty decent speeds ( low to mid 80's ). Second I ran them in gas setups as well that had tons of torque/power & never once did I spin a square ended flex. I myself prefer round flexes but hey everyone has their own opinions.

[MrUnlimited]

Squares are less stressed under load since they move more freely and they don't break easily.

[Chrisg81983]

Ok that's good to know thanks

[Alfa Spirit]

What is exactly the setup for the Mystic?

- Motors and kV ?

- 10S batteries for each motor?

Thanks

[Xcesive8]

My thought
Twin 12s 1527 90+
I thing it is possible also 1kg lighter.

Hi JKR, just to give you an idea.
I have a HPR135 it has twin 1527's 1.5y which is 825 or 850kv cant remember.
But i ran it on 12s a side once with some of my smaller props thinking id start slow amd work my way up.
It ran 86mph or 138 kph on 2 garmin forerunner gps.
Unfortunately it blew over and i cracked my hatch and it destroyed my schulze 40.160's cos i was in salt, along with batts etc.
Ive never got it up and going again since.
I had propshop 5517 or 5518 3 bladers to put on it as well as x457's but never got a chance.
So i think it would def get over 90mph with these motors.

Ryan

[nata2run]

Hi JKR, just to give you an idea.
I have a HPR135 it has twin 1527's 1.5y which is 825 or 850kv cant remember.
But i ran it on 12s a side once with some of my smaller props thinking id start slow amd work my way up.
It ran 86mph or 138 kph on 2 garmin forerunner gps.
Unfortunately it blew over and i cracked my hatch and it destroyed my schulze 40.160's cos i was in salt, along with batts etc.
Ive never got it up and going again since.
I had propshop 5517 or 5518 3 bladers to put on it as well as x457's but never got a chance.
So i think it would def get over 90mph with these motors.

Ryan

That's exactly what I got with my 2250 Lehners 137km, but with 447props. I think both the 1527 and the 2250 are a bit on the small side for a hull this size, although mine were never intended for this hull. Definitely a huge improvement with the 2280's. I'm strongly considering running 12s in wye mode. Would be around 860kv. That would get me around 40k rpm and keep the current down. Should be real fast!

[MrUnlimited]

Guys,

I am moving this thread again upwards I like to know what servo do you guys recommend. How many kg's in torque? Will be 18kg be enough? 1/5 scale servo? I am updating tonight my blog.

[MrUnlimited]

Blog updated with 2 new pictures. www.v10power.ws