Mean Machine Catamaran

[10gauge]

Greetings! I thought I'd share my first build project with the forum - A Brushless FE Aeromarine Mean Machine Catamaran. I mostly learned from pics online. Everything for this project was purchased from Offshoreelectrics.com (Steven is very knowledgeable and honest). Here's my initial set up:

Motor: Feigao 540-8XL (2084kv)
Battery: 14-cell IB4200 NiMH
ESC: Castle Creations Hydra 120
Prop: x442/2
Hardware: All Speedmaster. 0.21 Round Bottom Strut, 6in Rudder (Cut to 5in).
Connectors: 5.5mm Gold on ESC and motor, Deans on NiMH
Floatation: 2in. Foam Pipe fittings for 3/4in pipe.
Sealing: 3M 5200 Marine Sealer on all external fittings

The trickiest part of the construction is making sure that your drive line is straight from motor to strut. With a propane torch, anneal the brass stuffing box until it's red, except for the last one inch at each end. Most designs seem to have an "S" shaped drive line. I think this increases drag. For the motor mount, I hammered out a more steeper motor angle pointing into the hull, so that I ended up with a "C" shape drive line for less drag. I placed 3M 5200 Marine Sealer on all external fittings and hardware to create a waterproof seal. The boat runs bone dry.

It's important to prop down on your first run, and come in to check the temperature on the motor, ESC, and batteries after 1 minute. Use a timer! On its maiden voyage, I started with a x440. I am happy with a x442 for now using NiMH power. The Strut angle is 0-degrees and you may have to move the batteries to the bow or stern to get the proper weight balance on your set up.

To ensure that everything runs smoothly at first, I am running on 14-cells. This set up runs 40mph. I'll step up to 4S2P LiPo after a couple of more runs and most likely prop up to a x642. At some point, I may substitute my Feigao 12XL motor with 6S LiPo. With either LiPo set up, it should run 50-55mph. The limit of stability of this hull is 60mph and can turn at 40mph.

I would appreciate any advice or suggestions from your experiences on the Mean Machine. Thanks guys!

A huge step up from my SV27. My first RC boat ever was the SV27 where ultimately, some fishing line wound around the prop and pulled the back end of the boat down into the water. No rescue boat around - End of Story! I was told that people go bass fishing in that part of the pond and just toss the broken lines in the water. FYI: Ask around, know where you're running your boat and avoid fishing hot spots!

[kal1b3r]

holy crap, nice boat. that is insane. that is one sick ride

[ReddyWatts]

Nice job on the boat and the thread.

[whiplash]

nice CAT, we had our sv's nose dive in 3-5 feet water, stuck in the mud with prop wash billowing out of the water. submerged for a good 15-20 sec.......
seemed like eternity, lol, finally pop back up and continued the race. suprisinly enough, only a 1/4 cup of water in the hull. wish I had a vid. Aloha

[Eyekandyboats]

nice lay out

[RCprince]

Sweet Boat, clean and crisp....

[Fluid]

A very nice build. I'm glad to see you used a longer rudder, my MM would not turn well with the small "mini" Speedmaster rudder. Mine runs best with the bottom of the strut set about 1/4" above the sponsons and with about 1 degree of up at the prop end. CG at ~ 9.2" depending on water and wind conditions. The boat runs on the last 3" of the sponsons, clean and quick.

One note concerning my pet peave about the brass tubing - DO NOT ANNEAL IT - THAT IS TOTALLY UNEEDED! I don't know how that myth got started, but you can bend new tubing just fine with your fingers and it will not collapse. I've bent 3/16" K&S tubing in a 3" diameter circle using my hands, and no collapse. I bend stuffing tubes for my 4-cell rigger and my 10S cat without annealing and with my hands. The downside to annealing is you end up with a dead soft stuffing tube that will bend too easily during use, will not hold a setting, and will wear more rapidly. Unless you're a weak girl, don't anneal your brass tubing!

[10gauge]

Thanks guys for the great inspiration, comments, and solid advice on my first project. If it wasn't for guys like you in this forum I couldn't have been successful building such a project. All of you have provided a valuable resource of pics, set ups, and dos and don'ts...

Thanks ReddyWatts - I am glad to share my thread with the group, especially if it will encourage a potential builder to take the initiative of building on their own. Thanks Fluid - I'll try not to anneal the brass stuffing tube on my next project which will be the M-1 and a micro hydro or cat. I'll let you guys know...

Building and riding rc boats has recently provided me with a great escape to relax when I am not doing surgery in the office.

[Camman]

Very nice 10gauge Have you had a chance to shoot some video.

[Diegoboy]

Shouldn't the ESC be cooled first? Since the motor get's hotter, the water may be now warm from coming off the hot motor. Just something I was thinking about.

[Jeff Wohlt]

I really thought the 8xl was too hot for a heavy boat and 14 cells. I am using a 9 or 10T on mine soon.

[10gauge]

Camman, it's 20-25 degrees and all the ponds are frozen here in Boston. I'd like to take some videos as soon as it starts to warm up, but it won't be until about April-May.... Yawn!
I am going to experiment with other motor/prop combinations. I am also working on a Micro Cat and an M1 SuperCat. I'll let you guys know. It's great to hear that there are so many of you that can pursue this hobby all year round.

[10gauge]

Here is a video of the first Run of 2008!

I decided to experiment with a different setup on my Mean Machine. I changed the 8XL motor for a 9XL motor. On the videos, I ran conservatively for the first day to test out the new ESC and 9XL motor. I'll substitute different props next weekend and run 4S2P. Thanks ReddyWatts and SJFE for the advice on posting videos.

Interestingly, on the 14-cell NiMH packs, the wire/plastic on the negative terminal started to melt after the 3 minutes - I'll have to strip the 14ga wire and thin tabs and solder 12gauge wire directly to the terminal cell. Similarly, running 2P on the 9XL motor might be a better alternative than 1P.


Mean Machine Setup 1:
Motor: Feigao 9XL - 1853kv - (temp. cool)
Hextronic 14-cell NiMH IB4200s - (temp. v. hot)
ESC: Hydra 120 - (temp. cool)
prop: m440
speed: 38mph

http://s298.photobucket.com/albums/m..._14c_m4401.flv


Mean Machine Setup 2:
Motor: Feigao 9XL - 1853kv - (temp. cool)
Hextronic 4S1P/4100mAh/15-25C - (temp. hot)
ESC: Hydra 120 - (temp. warm)
prop: m440
speed: 42mph

http://s298.photobucket.com/albums/m..._4S1P_m440.flv

http://s298.photobucket.com/albums/m...4S1P_m4401.flv

[calcagno45]

Awesome videos man!! You can really tell the difference in speed between the 2 different types of cells.

[OJ racer]

Personally, when I bend brass tubing I fill the tube with salt then bend it. If you really pack it in it gives you almost a hundred percent guarantee it will never collapse.

[andym]

Guys you might not know this but when you anneal copper or aluminium or brass it will air harden over time to almost its original strength. I know it sounds crap but try it out, heat some and see how soft it is then leave for a month and try again,, you will be surprised. A metalurgist friend of mine explained how it works but all I care about is that it does. I live in a large mining town and have asked several metal heads and they all agree.

[Camman]

Looking great! 10gauge. Keep the vids coming please
Nice lake by the way too:-)

[10gauge]

The appreciation is mutual. I am glad to share these and more videos in the future. It's taken me a year to find this lake, and frankly it's the best one I've run boats on.