DIY twin motor mono build 'G-Force'

[Dirk Jan]

Hi fellow boaters,

Last year I built a 32" Wildthing that I slightly modified. It started as a 60+ mph boat build, but it proved to be quite a bit faster with 75mph top speed.



I enjoyed the build and performance so much, that I decided to build a twin mono. It is again based on the Wildthing, but I modified the design a lot. This boat is 33.5" and will get dual stinger drives and a 6S setup. Most likely 2x 3674 2000kV motors and 150A Flycolor esc's.

Here's the design, although it still had a single motor setup here:



I cut the frames and set them up at the building board.







I also upload the build on YouTube, if you are interested:

https://youtu.be/yWzgx5EuzPM

Next step is apply the bottom and side sheeting and release the hull from the build board.

[Bande1]

watched the video this morning. will stay tuned.

[ray schrauwen]

Yep, I'm subbed. Nice builds!

[Dirk Jan]

Thanks guys!

Here's part 2 of the build:
[MEDIA=youtube]mxPtTZE4NVQ[/MEDIA]
I progressed a bit more after that. Here are some photos of the 200gr/m2 carbon weave I laminated into the hull.

I put fillets of thickened epoxy (with micro balloons) in every corner.

By using paper templates, I cut the patterns of each weave to size.

All together quite a fiddly process. The hull feels very strong already.

I will also laminate the longitudinal bulkheads with carbon fiber.

[fweasel]

Very nice

[Notoriousone]

Clean work, looks great

[Dirk Jan]

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.

[sammyha]

Very cool build! Love all the DIY components...

Sent from my SM-G950U1 using Tapatalk

[Dirk Jan]

Thank you Sam

Here's build video part 3:

https://youtu.be/-2ApIcxzQng

[Notoriousone]

Besides the boat itself, I like your build videos, they’re fun to watch because of the fast pacing and good editing.. I like seeing precision work being done, I’m subscribed

[Dirk Jan]

Thank you Notorious, I appreciate that!

[Dirk Jan]

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.

[Dirk Jan]

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

[Dirk Jan]

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.

[fotis zzr]

Respect to this guy. Love his DIY skills

[Dirk Jan]

Thanks Fotis

In the meantime I glued the deck to the hull and I glassed it with a double weave. I also installed one of the two drivelines:

https://youtu.be/lVUQCtlFBIc

[Dirk Jan]

Next 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

[Dirk Jan]

Next 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

[Dirk Jan]

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 came 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.

[Panther6834]

Looks absolutely fantastic. Just remember that forever CF is never as strong as sheets. A good comparison/example would be the Zeus decks from Ownboard (electric skateboards, in case you didn't know). They offer decks made from sheet, and forged decks. Physically, both have 100% identical external dimensions. Whereas the sheet decks are hollow, with a honeycomb inside, the forged decks are (from what I understand) 'solid'.

Even as thick as the forged decks are, they've proven to not be as strong as the sheet decks, and several have snapped...some somewhere in the midsection, others close to the rear of the front truck or the front of the rear truck. Granted, the rudder bracket won't see as much 'force' as standing on a skateboard...but, at the same time, the bracket is considerably thinner than the skateboard deck. As gorgeous as your bracket is, I really hope it does hold up.


~ More peace, love, laughter, & kindness would make the world a MUCH better place

[Dirk Jan]

Thanks Panther, for the detailed feedback. I'm curious about the strength too. This bracket is quite long, so I'm a bit concerned on the impact on the bracket and transom, when I crash the boat. I'm thinking on using plastic bolts to mount it to the transom to prevent big damage. I rather want it to break off, than rip the bracket or transom apart. Hopefully it will stay attached with the steering rod.

It's an experiment all together. Let's see how it holds up. My Wildthing used to have a wooden rudder bracket (glass laminated), which lasted surprisingly long.

[Panther6834]

I can see that. Some wood can be quite hard & strong...for example, cherry, and walnut.


~ More peace, love, laughter, & kindness would make the world a MUCH better place

[Dirk Jan]

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

https://youtu.be/Vu24nmIwHcc

[Dirk Jan]

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

[Dirk Jan]

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 62 ad 64mph on the runs. It's a good baseline, from where I will work on increasing the speed.

The Speed goal is 87.5mph (140km/h) so the tuning journey starts now.

https://youtu.be/kvRE6xOLRbg

[BUMBLESPECIMOODA]

Sure is a pointy boat.

[Panchothedog]

After watching your video, for a 1st run fanastic. Very well done. You might need a bigger pond to run in to hit 140 kph.

[Dirk Jan]

After watching your video, for a 1st run fanastic. Very well done. You might need a bigger pond to run in to hit 140 kph.

Thank you. The pond is quite big; if I stand in the middle I can use the part near the big building too. I got 123km/h there with my Wildthing, so I have good hope I can push the speed a bit more over there

[Dirk Jan]

I made some improvements on the G-Force.
I added a brace to the rudder arm, and I sharpened and balanced the props.





I can't wait to take her out again and set some speed numbers. Here's the video of the modifications:
https://youtu.be/K1tKlTvbvL0

[ray schrauwen]

I can appreciate your builds and videos. I used to do scratch building like this before the internet and world market for all things RC or electronic. Now I usually buy a hull or a wood kit and build them up.

The amount of work to do this is staggering and I salute you my friend of the Nederlands. Orange would look great, there is a nice orange color by VW, the code is not handy at this time however... Thanks for sharing, I look forward to future post and videos.