DiY twin mono 'Cozy G-Force'

[Cozy RC]

Bonjour rc friends! I started a new build. A twin motor mono hull, based on the John Finch Wildthing. 

Length: 850mm

Width: 245mm

Motor: to be decided, probably 2x 3670 1850kV 

Esc: 2x Flycolor 150A 

Lipo: 2x 6S

The boat is made from wood with carbon and glass laminate. 

I make a YouTube series of the build:

Here are some pictures of the build:

 

[Cozy RC]

Thanks guys. I continued the carbon laminate on the longitudinal bulkheads and the deck plates.
The deck is just attached by tape for now. 

I got 2 Rocket 3670 1850kV motors and 2 Flycolor 150A esc's.

I'm also working on DIY stinger drives. The stinger tube will finally be made from carbon tube.

[Cozy RC]

Here's build video part 3:

https://youtu.be/-2ApIcxzQng

[Cozy RC]

I filled the bow with pool noodle and I cut the deck opening. The deck is not attached yet.

I'm now working on the twin motor mount:

I modified the Flycolor 150A/ OSE 150A esc For a more efficient cooling and smaller dimensions, to fit this hull.

 

[Cozy RC]

I put some effort in making my own stinger drive from scratch. Why? Because I love DIY building 😎

Here's the video of how I made it:

https://youtu.be/9_SWOKJzwJY

 

[Cozy RC]

Bonjour RC friends,

Here's part 5 of the build:

https://youtu.be/Fute3fWXF_U

The sides are glued and laminated to the hull, flotation is added, the motor bracket is made and the deck is fitted with the hatch support.

[Cozy RC]

Bonjour guys. Here's part 6. I glued and glassed the deck and installed the first driveline:

https://youtu.be/lVUQCtlFBIc

[Cozy RC]

Bonjour RC friends. In this update, I made the lipo tray from carbon fiber. I made my own carbon plate. It's a fun and easy process, explained in my video:

https://youtu.be/AIdWwneWwVg

[PHIL94]

Vidéos toujours très instructives .

[scyllias91]

Super explication 

[Cozy RC]

Bonjour! In this episode no 7: I worked on the hull bottom, adding spray rails. Also I glued the lipo tray in the hull:

https://youtu.be/-Q6eAIY1pgc

[Cozy RC]

Last week I made a rudder bracket from forged carbon fiber.

I made a mold from wood and taped it to prevent the carbon and epoxy mix to stick to it.
The mold has a top part, which presses the  carbon and epoxy together.

The part game out nicely. After making some cutouts and a lot of sanding, this is how the part turned out:

I will edit and upload the video of the process this week.
 

[Cozy RC]

Here's the video of the entire process, from mold making to finished product:

https://youtu.be/Vu24nmIwHcc

[Cozy RC]

I made good progress with the build. I installed both esc's, reinforced the lipo tray, made a servo mount and modified the hatch for the gps signal.

Here's video part 8:

https://youtu.be/z2GtastEDJw

[brushman]

Hello,

nice built, where is the CoG? 

[Cozy RC]

Thank you Brushman. Good question. It can be moved by shifting the lipo's. I just ordered the correct lipo's, which will be lighter than the current lipo's in the boat.

I hope to get the cog at 30% from the transom. 

[jerome lefebvre]

Hi Cozy 

Nice work on your Boat from John Finch 

A great Man in RC Boating 

I really love your home made hardware.  
Using carbone fiber and aluminium. Make it look good 👍🙏

I am wondering how it will run with in a Shallow Vee 

regards Jérôme 

[Cozy RC]

Merci Jerome! John Finch made a great design with the Wildthing. This twin mono is based on the Wildthing, but has a different bottom and top design. It is also more narrow. 

The Wildthing that I built, ran great and 120+ km/h on 6S. Until I crashed it 😬. But I will repair it for next season!

[jerome lefebvre]

John Finch being my mind master 😁 since the Mid 90’s  and even today 👌

Good idear to Make a bit narrow    It’s good for top Speed like you do ✔️ 
Keep on going 💪🙏

A++ Jérôme 

[Cozy RC]

Thanks Jérôme! I hope the smaller hull generaties less lift too. The Wildthing wanted to get airborne above 110km/h.

Here's the next update. 2nd stinger is finally installed! Wiring and motor cooling is sorted as well. 

The ponds are frozen here, but I hope to run it in the next few weeks 😎

[jerome lefebvre]

Hey hey Cozy 

You welcome 👍 

Îm looking forward to watch some vidéos on runs !! 🙏 You did some awesome Work with in your Hardwares. 
keep it up !!!! 

[Cozy RC]

The G-Force had it's maiden run this weekend. 

I ran 2x 2 lipo's and the boat handled pretty good. It has a little bounce and it spins out in tight corners, but I will work on that for the next run.

I got 100 and 102 km/h on the runs. It's a good baseline, from where I will work on increasing the speed. 

The Speed goal is 140km/h so the tuning journey starts now.

https://youtu.be/kvRE6xOLRbg

[brushman]

Hello,

yes, I think you will try many rudder blades lenght and width,  this boat flies and when you will put higher pitch props, it will lift the transom, and then you will move the COG backwards,  you may reach high speed but the boat will not stay on the water, may be, a "very" long rudder blade will create some drag and maitain the hull leveled, or the flaps but they are not close to the center...

good luck!

[Cozy RC]

Thank you for your advices Brushman 👍. These golden props are 43mm 1.6 pitch props. I thought they might be a bit big, but I think less prop surface is in the water, compared to a single motor in the hull centre. In that sense, I could probably run even bigger props. 

Sharpening these golden props is the first next step, together with a longer rudder blade. I will also experiment with the centre of gravity and the stinger angles.

I cannot wait to run this boat again. I hope to break my speed record multiple times with it and make some nice video content 😎

[jerome lefebvre]

Hey Cozy. 
Pretty good runs you did on vidéo 👍🙏

I totaly agree with Brushman advices 🙏 

As John Finch wrote in the passed years down in Rooster Tail. 
Faster you go !! Gc need do move up front. 

Because !! Air pressure in between your Hull and the water will be higher as you will get faster  !!!  
Moving up the GC !! should help you !!! to keep away from blow off 👍🙏
Keep it up. Jérôme. 😁