Project DTT (another build from Munich)

Hey guys,
Time for me, to say “hello”. My name is Sebastian, 37 years old and from Munich Germany. I´m an electrical engineer and work as hardware developer. I´m doing wakeboarding for almost 15 years now, and maybe I become too old for that  so i want my own e-foil now… I finally start my “Project- DTT” now and due to the “actual situation” it went pretty good so far. “DTT” stands for “Don´t tell Tina” (my wife)  because I have so much unfinished project, that another one would cause me too much trouble.

After reading a lot in this forum (pretty awesome by the way!!!) I don’t want to build the motor system and foil by my own. The flying rodeo system seems pretty good and I want to go with it.
But I want my own board. First I was looking for a company, which cnc machined boards, but dint found one…There is a company in Austria which also sell styrofoam blocks for surfboards and offers CNC jobs, but they didn’t respond to my mails. And the blank styrofoam blocks are ridiculous expensive. So I decided to build my own 2x1m CNC. It’s the very common MPCNC and for milling styrofoam it´s rigid and accurate enough.



First tests went excellent…

9 Likes

Of course you can´t hide such a huge CNC in an apartment, so my wife already know about “Project DTT”. The good thing about that is: my wife is also an engineer for automotive engineering and she has some amazing skills in CAD. So she designed the hole board. It´s about 1550x520x110mm.




4 Likes

Nice build of tools already, thats part of the project as well :slight_smile:
The board looks good, a few remarks to consider:
The thickness of 110mm, can you accommodate the hatch and battery box In that height? In my build I need >100mm for those components. (Batt box 90mm, hatch 10mm)
At the underside of the board the water needs a sharp(er) edge at the back of the board to let go, loosen the flow along the underside. Ofcourse this is only an issue when starting, on foil it is out of the water.

Good luck with the build!

Awesome design ! What is the density of the syrofoam ?
Thickness is great if you want to use your own battery.
Regarding width, I would recommand a wider board.
Lift Sport is 152cm x 63,4cm
FliteBoard Pro is 152,4 x 62,2 cm

Also, as mentioned by @JvdZ, the back of the board needs to be sharp. Otherwise, the water will suck up the board, therefore needing more power to get on the foil.

Hello again,
thanks a lot for your feedback. My CAD department changed the design a little bit.
The board is now 1560x590x110. I use standard Styrofoam blocks from hardware store. Unfortunately these are only available in 1250x600mm, so 590 is the pretty much the limit in width. I also have to split the board in 4 pieces.

The picture is the comparison between old and new design.


With a quite simple Hotwire and a template from the side of the board I roughly trim the blocks before cnc milling. This safes a lot of milling time and dust.

Next Weekend is milling-time!

1 Like

Its Miller time :rofl: :rofl:

1 Like

Hello again,
the weekend was very productive. Took the CNC about 5h for each side.

Just a bit of sanding and i can start glassing. I will use 2 layers of glas and 1 carbon fiber. As reinforcement I want to use carbon fiber square tubes. The mast plate will be screwed to these tubes later.


3 Likes

Superb and promising :+1:
Seems like it is not part of the project but it looks tempting to flip the board and CNC an electric box as well.
What are the specs of your 2m x 1m CNC: working surface, motor power, routing bit (s), motor driving cards ? Which rail system are you using ? CAD/CAM software, LinuxCNC ?

Thank you,
the electric box will be cut by the CNC later. First I want to glue the board together. The elective box, due to its size, is placed in both parts (top and bottom). It wouldn’t be possible, to mill it right now.
The working surface of the CNC is 1600x600x150mm. Pretty much the size of my board.
I use a very cheap brushless china spindle with 0.5kw. Although I strongly doubt the 0.5kW, the spindle did a good job so far. It´s more than enough power for the styrofoam. Big advantage is the ER16 tool mount. With that I can use bits up to 10mm.
I use a 10x90mm drill bit with 50mm cut length special for styrofoam.
The CNC is controlled by a rambo 1.4 board. But I wouldn’t recommend it. There is almost no support out there and also Estlcam doesn’t work with this board. I use 25mm stainless steel tubes as rails.
And I use Fusion 360, but only for CAM. The board itself was made with Catia.

2 Likes

Great work Sebastian!

I’m planning on doing the same for my board, I have a friend who does wood design and have a pretty big CNC. Would I need the special styrofoam drill bit?

What are you planning on doing for the electronics box? I’ve looked at different boat hatches etc but didn’t find any good alternatives.

Lars

Hey Lars,
Yes, i used a special styrofoam drill bit. But I don´t know, if you really need one. This one did a good Job for me.


The bigger the drill bit (diameter and cutting length) the more time you safe. In my case, I was able to finish the board with just one 3D cam operation without roughing and it still took me about 5h. But what you definitely need is a cyclone dust collector. These dust goes everywhere and it becomes electrostatics.

I am planning to 3D print my electronic box and glue it with the 2 layers of glas into the board. I dont want to use hatches or something like this. I will use a straight carbon fiber cover with a lot of screws.

1 Like

One of the most strange things I have ever seen :slight_smile: I don’t know how it looks like now, but 20 years ago that was kinda weird tool

Nice work bro @ Gravity. looks really good
Any chance you can share the cnc file or cad file please. Will be very helpful as i have no knowledge regarding the drawing. looking forward to build one for me.

Thanks