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DiY Mini Mono


Cozy RC

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Bonjour French friends,

Hereby I share my latest project: a 500mm long Mini Mono, based on John Finch Wildthing. 

I share the drawing for free, and you can download it here: https://drive.google.com/file/d/18h5v1BeNiVeqVx38g8DY5kYUVbUtM2Ao/view?usp=drivesdk

I started with sticking the drawing parts to the wood, for cutting the frames. You can use 2-3mm plywood:

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I added 1mm thick birch plywood for the plating. No fibreglass, just glue:

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Next to it's big brother, which I badly crashed previous season:

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I added the servo tray and the motor. I start with a 28mm 2600kV Roxxy inrunner, which I still had:

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I added a cheap rudder, with water cooling pickup. Basically, all parts I used are very cheap:

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I made my own trim tabs and turn fins: 

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I made the cockpit from hard foam, laminated with 2 layers of glass weave: 

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Ready to run! It weighs just 873 grams including a 3S 3000mAh lipo:

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Maiden run! It runs so great, I'm in love 😊. It handles very good. It can take corners at full speed. The top speed is 53km/h with a 435 brass prop.

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I made a 3-part video build series of this little boat. Here's the playlist, if you're interested:

RC Mini Mono build series:

 

My sons will enjoy this little boat now. Soon enough, I will start upgrading it 😎. Adding a Rocket 2948 3450kV motor at first, running on 3S, and maybe try 4S. I would love to get 80km/h with this Mini Mono!

 

 

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Very nice build!

If I may.

The prop nut is really big. It creates a weight too far from the bushing, with potential vibrations.

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Hi Jérôme, thank you! Yes, you are right about the prop nut! I didn't use it, and used a lock nut instead 😎

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Today my sons tried the Mini Mono. We had lots of fun, and I had a bit of stress sometimes 😅

After my sons finished 2 lipo's, I tried the boat on 4S. The Mini Mono got insanely fast, and I got 80km/h.

Here's the video of today:

 

 

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  • 2 weeks later...

I'm now making a carbon hull. I made my own carbon plate from 2x 200gr/m2 weave. Laminated with 45 degrees angle between the weave strands.

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The transom is still 3mm ply, so I can use inserts to install the hardware. I laminated the seams with a strip of weave, after gluing the hull together. It's very strong, and so far just 88 grams for this 50cm hull. 

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  • 2 weeks later...

I made some progress:

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it will get a DIY rudder and a water pickup in the hull bottom. I think that solution has less resistance than a thick rudder blade with water pickup.

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Fully right concerning the water pickup

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Yesterday I ran the wooden Mini Mono again, with my sons. It was great fun! We got 58km/h with new 3S lipo's. 

 

I made some progress on the carbon version as well. I made the lipo tray from 3x 200gr/m² carbon weave. I will use a 60A ZTW speed control for this one.

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Brothers:

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hi Jan,

did you check if your carbon hull is watertight ?

For racing in the mini mono class the lenght should not exceed 45 cm :-)

Arsène

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Hi Arsène, the hull is not yet water tight. It has many pin holes still. But I will cover it with a thin epoxy layer when I finished the setup.

I named it Mini Mono, but I understand that it is actually a racing class, which I don't pretend to match with this boat 😅

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  • 4 weeks later...

Today I ran the Mini Mono with the recommended Rocket 2948 3450kV motor. It is a great setup on 3S. The top speed is 72km/h and corners can be taken on full speed.

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6 hours ago, dodo59 said:

Plus de 50° accus mort.

50°C is near the edge, I agree! I read a lipo is allowed to reach 60°C while being discharged, but it wont be good for the lifetime of the lipo, if they run hot all the time. I pushed the hull quite hard though.

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  • 2 weeks later...

Bonjour RC friends, here's a video on the Carbon Mini Mono progress. I show how I made the carbon stinger, the water cooling, and the making of the cockpit hatch.

 

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  • 3 weeks later...

Last weekend I ran the Mini Mono and Mini Hydro. 

The Mini Hydro has a very similar setup: 3S, 3900kV, 31mm prop, 60A esc

Mini Mono: 3S, 3450kV, 36mm prop, 60A esc

The Hydro corners faster (as expected). The top speed is just 1km/h difference! Both boats are a lit of fun!

 

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Hi,😁

Great tests and good job 👍 Love it 🥰 👏

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The mini hydro, it's a personal construction in wood ?

Top speed 👍🥰

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1 hour ago, jojo76 said:

The mini hydro, it's a personal construction in wood ?

Top speed 👍🥰

Thank you! Yes it is. It's a Hydromite Mini Hydro, designed by Doug Forrester. You can find the drawing online. 

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  • 2 weeks later...
  • 4 months later...

I developed the successor of my Mini Mono: the Cozy M500 Mini Mono.

Here's the maiden run video:

 

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