Mean Machine Catamaran (Sport)

[DISAR]

me too

The amps are a little higher than they should be, I can say the following

a) You can reach higher speeds only with bigger prop, 445,645
b) Your amps will increase too and maybe the etti will let go...
c) I suggest to cut some part of your rudder, at least 1" ( I cut mine too and turning was same and better performance)
d) This is quite difficult to do but you should do it sooner or later, it is the stuffing tube angle. It creates unnecessary resistance BOTH water and friction (one cause of your high amps). You need a uniform radius from the point it exists the hull until the strut, no need to be straight only before the strut and motor 2" about. Lower the motor angle as well, pls see attached rough sketch
e) Batteries about 1" from the back

Speeds are relative and depends on many conditions (gps-water-chop-density-sea-fresh etc...) (I have never achieved the speeds mentioned here even with same boat-setup)

[Jeff Wohlt]

Me too -- about 1" from the transom.

[Brushless55]

I run my batteries all the way back in my MM
and for me that helped a bunch

[Rumdog]

Prop is WAAY too small! Need a gap between the strut and drive dog. Thatg bend in the tube could also be causing excessive drag,and amps.

[BakedMopar]

580 6l and your only getting 36-40 mph? Something must be wrong.

[Rich]

well i ran my MM tonight and a got some good results, i moved both lipos back about 2 inches from the back, 125.57 amps, 1660 watts, temp of esc 114f, motor 85.8f, speed though was 36mph, my prop came off when i let off the throttle thats ok though it was worth it, I order some different size anyway.

> My tube is a bit excessively bent but i could not make it a sweep, do to the motor being at angle which it needs to be to fit under the cowl. The flex seems to be holding up, i don't see any where on the Teflon tube but time can only tell that story.

[Xfactor]

So the smaller the number 8xl has more torque than a 10xl? What is the max you can spin an xl motor? C

The lower kv motors have more torque.The 10xl has more torque.

[Brushless55]

I thing the CG needs to be moved back..

[Jeff Wohlt]

And cut off some of that rudder! You only want about 2.5" under the water. It is tappered and I don't use those but still I would remove some for sure.

[knpc]

It could be the picture, but the stuffing tube looks to have a abrupt bend instead of a nice long sweep. It could cause resistance that would lead to slower speeds and higher amps.

[Jeff Wohlt]

That stuffing tube bend is EXCESSIVE! There is some of your problem...you are going to eat something up like that...probably the cable and the tube.

If you are pulling those amps you have issues. You should be in the 80-100 amp area. I am running a X442 and only warm after dumping the cells.

[Rich]

here are the pics

[Rich]

The first problem is the prop - it's too small for that motor. Try an m445 or m645 and see how it runs. The overall setup looks good from the photos, but a few questions:

- Exactly where is the CG now?
- Set the boat on a flat surface - where is the bottom of the strut relative to the sponson bottoms? What angle?
- What timing advance are you using on the ESC?
- How much gap between the strut and the drive dog?



.

Fluid you are the one i was hoping would answer since your neu mean machine was my inspiration for this project . I want to hit 60 tops, but 50 to 55 would be ok if 60 is not possible.

>Anyway i have attached some photos of my CG, the center line of the batteries are just behind the 9.25" red tic mark which is 33%

>The bottom of the strut is actually 3/32" from the bottom of the sponsons not 3/16" like i had stated before and the angle is about 1.5 degrees. I can't move the strut much more with out having to bend the stuffing tube again as you can see in the pic.

> I am using a timing of 1 deg since this more is a 2 pole motor.

>As for the gap i used 3/16" for the run that pulled 150 amps, i notice some water in the hull and added a piece of fuel tubing b/t the drive dog and strut, I raised the strut and the amps were 141 i know that there needs to be a gap, but i don't have enough cable length for it with the fuel tubing thought i still have a leak somewhere...

As for you prop suggestions, wouldn't i gain amps if i switched to a bigger prop? After I raised the strut for the second run i noticed that the prop cavitated up until just after1/4 throttle and the thing took off!

Fluid did you shorten the rudder on yours like the others down below have suggested?

Thanks everyone!!!!

[blackcat26]

I'd run the cooling tubing to the speed control first then motor.....It takes #1 priority on being cool, motor second.

[sailr]

you're gonna demagnetize the Feigao at those temps and then it will destroy your esc. Ask me how I know!

It looks to me like way too much weight in a MM and way overpowered.