M1 Superkat

[Flying Scotsman]

After Steven's bombshell of the new Jolly Cat. I am left with my new M1 Supercat. I am thinking of direct drive KB45 10XL. M445 prop..Sentillon 100 ESC. Here comes the question? 4/5/6 lipo cells or ?

Douggie

[SJFE]

Well with a 9XL on s6 you will be turning about 31000..It maybe a little hot but backing down to s5 only puts you around 26000 so you would have to wing a pretty hefty prop. Tuff one man. If it where me I'd go 5s-2p

[Flying Scotsman]

Well with a 9XL on s6 you will be turning about 31000..It maybe a little hot but backing down to s5 only puts you around 26000 so you would have to wing a pretty hefty prop. Tuff one man. If it where me I'd go 5s-2p

Please note this a KB45 10XL rated at 1200 Kv. I think that 5 cell lipo and X445 or M545 will do for sport/ racing purposes. But I await your answers.

[Darin Jordan]

I don't think 31,000 or so is that unreasonable for racing purposes... My N2-Mono is around 35,000 and my P-Mono will be around 30,000... I'd run it on 6S for sure...

The question is what can the motor take... I think it should be fine up to 6S, which should yield you around 26,600 on the low side (3.7V/cell nominal), and 30,240 on the high (4.2V/cell fully charged)...

Good Lipos hold around 3.7-3.8V under load from what others I trust have told me, so I think that a 6S system should work fine...

Just my 0.02...

[ReddyWatts]

It seems like the lower KV motors from Fiegao and KB need smaller props than you would think. I ran a KB45 10XL on 24 cells and a Y537/3 prop yesterday. Lowered the bottom of the strut, even with the bottom of the hull. It was screeeeaming at the fastest speed yet. It did cavitate a little from a dead stop, but from 1/4 to WOT, it was a monster.

It is running over 30,000 rpm.

[Flying Scotsman]

It seems like the lower KV motors from Fiegao and KB need smaller props than you would think. I ran a KB45 10XL on 24 cells and a Y537/3 prop yesterday. Lowered the strut even with the bottom of the hull. It was screeeeaming at the fastest speed yet. It did cavitate a little from a dead stop but from 1/4 throttle up, it was a monster.

It is running over 30,000 rpm.

Thanks, lads but the M1 is 34" long. That is why I thought a larger prop would work with 5 cell lipo???

[ReddyWatts]

Thanks, lads but the M1 is 34" long. That is why I thought a larger prop would work with 5 cell lipo???

I am running it in a M1, just saying try a smaller prop than you would think on the KB 45 10XL to get its best output.

[Flying Scotsman]

[QUOTE=ReddyWatts;15074]I am running it in a M1, just saying try a smaller prop than you would think on the KB 45.[/QUO


Mr. Reddy, thank you for your info. I will try an X440 to start

[Darin Jordan]

Thanks, lads but the M1 is 34" long. That is why I thought a larger prop would work with 5 cell lipo???

I don't disagree... I'm just saying that, if the motor is up to it, that 6S AND the larger prop should also work fine... An X445 really isn't all that big really... Certainly not on a 34" boat...

[Flying Scotsman]

I don't disagree... I'm just saying that, if the motor is up to it, that 6S AND the larger prop should also work fine... An X445 really isn't all that big really... Certainly not on a 34" boat...

Darin, now I am confused. I thought a larger prop on a high torque motor made sense. Now possibly a small prop is better. High torque ...large prop..low torque..small prop. Please explain.

[SJFE]

I ran my KB 8 on 16 Nimh on a K42 in the jolly(also 34) and got about 35mph....but some scary temps. I moved to an s4-2p setup on a 440-3 and saw more speed and all temps around 100. It seems to like the lower voltage and smaller prop in that case.

[Darin Jordan]

Darin, now I am confused. I thought a larger prop on a high torque motor made sense. Now possibly a small prop is better. High torque ...large prop..low torque..small prop. Please explain.

I don't want to confuse you... Start out listening to the guys that have actually run these things...

I'm suggesting that you should be able to swing a large prop WITH the 6S voltage level on that motor... but I'm thinking in terms of other, 4-pole motors I've used... I don't know if your motor has the same performance parameters, so listen to those guys who have used them first...

[Flying Scotsman]

I ran my KB 8 on 16 Nimh on a K42 in the jolly(also 34) and got about 35mph....but some scary temps. I moved to an s4-2p setup on a 440-3 and saw more speed and all temps around 100. It seems to like the lower voltage and smaller prop in that case.

KB 8... S /L/ XL ?

[Flying Scotsman]

, so listen to those guys who have used them first...

Darin, you hit the nail. I am waiting for those that have run the same boat and power souce. Excluding reddy/watts as I am interested to his prop selection as he has run this combo

[SJFE]

Sorry Doug It was an 8XL 1700kvm.