First try on a (boat) drone for depthlogging

As an angler, I like to know the depths before I get there and run something more or less expensive in the bottom of the lake. Some newer chart plotter/fish finders units have a tracking software, which not only records the depth, but from some manufacturers also records the different kind of bottom structure (hard - rock, soft - mud and everything in between).

Ok, cool enough, a few friends and me have Lowrance chart plotters/fish finders. And with the Reefmaster software (www.reefmaster.com.au), we are able to make depth charts for our lakes, which can either be exported for our chart plotters, make a google earth output, 3d image, or just to be used as an image. 

But… some free time, and google and I found three projects that was "perfect" for me. 

The first one is the Sea Rendering project by Geir Andersen: http://letsmakerobots.com/node/21098 the next project I found was Haralds Molles "Ardupilot goes into the water" http://diydrones.com/profiles/blog/list?user=3um9qjnkq5rxo ;. The last project I found was The Ardupilot controlled transducer boat 3 by Burkhard Rieck http://diydrones.com/profile/Burkhardrieck

Three cool projects, and all of them ended up with what I wanted, a boat, that while I was fishing, sailed around gathering depth data.

After reading about this project, and thinking a bit, about what I wanted, I ended up wanting a catamaran, mostly because a single hull boat would be more affected by waves from both the side. Various bait boats have been using a two-engine setup, without a rudder.

In addition, I would like to try to keep the price as low as possible. 

So, ardupilot 2,6 from ebay
2x 12V DC 1000RPM mini torque gear box motors from ebay
2x Electronic speed controllers for brushed motors from ebay

For batteries I am going to use, 12V sealed lead batteries. At least one in each hull. 

Prop shaft, propellers and couplings are purchased, from a boat RC shop. 

My first plan was to use a 200mm pvc pipe, with a 45 degree bend as a bow, but after looking in a few stores for 200mm pipe, and only finding the 110mm I decided to build a hull with fiberglass. 

Which is where the projects is today. 

I have to admit that I have not a clue about the DELFTship software that Geir and Burkhard used to design the hull, I downloaded the free version, but, well, I could not figure it out fast enough. 

Both of them made nice moldings for the hull, I guess I could have put some more work into my hull, but as a test setup, or proof of concept I guess it is good enough.

I ended up with the quick and dirty version, kind of like the toy boats we made with throwaway lumber.

So, Styrofoam, glued together, cut with saw, and then a belt sander. Painted it and put aluminum foil in the paint, waited, and then a new layer of aluminum foil before the fiber cloth and polyester resin.

Styrofoam glued together.

Sawing and grinding it to...

...some sort of a mold. Glued to the last piece of styrofoam .

A few layers of aluminum foil...

... and covered with fiberglass, waiting for it to harden.  Ok, bad picture. :(

So:

I might have a form on my hull that is not 100% perfect, but this is version one.
The engine might, or might not be big enough
Geirs boat had a speed of around 2 km/h which seems a bit slow. Perfect speed would be around 9 km/t (5 knots) However, testing will decide a lot of stuff.

If needed:
The coupling on the engine makes it possible to swap to an engine with larger shaft.
New hull, well, It seems I have to learn DELFTship after all. Alternatively, buy something that could be converted for the purpose.

But those are for a future blog post. Most important now, is to make the second hull, and get everything in. :)

Images: Top images is part of a larger lake, where we have some information, but need more. Erik Grimsøen have used Reefmaster to produce that image. Rest of the images are taken by me, when we made the boat.

Views: 3014


Moderator
Comment by Gary Mortimer on May 26, 2014 at 6:59am

Now this I shall follow with interest


Admin
Comment by Thomas J Coyle III on May 26, 2014 at 7:16am

Hi Carl,

Nice project.

I found it easier to buy to size .60 fiber glass airplane pontoons rather than make my own molds and hull. The pontoons will support ~5 kg which is sufficient for the APM navigation system, a Garmin Intelliducer depth finder, assorted telemetry, batteries, and two custom outboard electric propulsion motors with 50mm three bladed props.

Regards,

TCIII ArduRover2 Developer 

Comment by Jim Pullen on May 26, 2014 at 7:17am

Me too, very cool.


Developer
Comment by Linus on May 26, 2014 at 7:30am

Thumbs up! We need more boats :)

Comment by Carl Stiegler on May 27, 2014 at 12:36am

Thanks :)

Made the other hull yesterday, and next week I'm going to paint them.


Thomas: I like the idea about the pontoons, but I haven't seen them here in Norway, and it's a bit late since I have made both hulls now. I found a couple on ebay, I might see if I order them if my hull needs to be replaced. 
5 kg is app the weight each hull needs to support. :)





Developer
Comment by Randy on May 27, 2014 at 5:14am

That's really great to see an autonomous boat take shape.  We don't see enough of them!

Comment by Burkhard rieck on May 27, 2014 at 5:24am

Hi Carl!

Great job so far! My first boat was just a pipe. After it worked out well, I put a lot of effort into the second boat.

At the beginning, I really didnt understand and like DELFTship but after several hours I understood the program. And now I just love it. Just keep playing with it and you will see that you can build everything with the Point, Edge and Face menu.

The length of a boat is a very big factor of the maximum speed:

http://en.wikipedia.org/wiki/Hull_speed

For me it was more important to have a small boat rather than a quick boat. But if the hull is to short, its nearly impossible to be faster than a certain speed.

Comment by Harald Molle on May 28, 2014 at 8:22am

Welcome on board!

I nearly have tried all possible alternatives for a boat:

monohull:

- bodyboards

 - styrofoam sheets

- model boats

catamaranes made of

- PVC foam sheets

- fiberglass coated styrofoam

- PVC tubes in various sizes (75mm, 110 mm, 125 mm diameter)

- and i ended up finally with a negative epoxy form in which i 

  laminated glass fiber with epoxy. (i also tried polyester too, but it is harder to

  process and adds lot of weight compared to epoxy).

 Boat size: 140 x 50 cm

 weight with payload 7-8 kgs

I also tried various propulsion systems and finally ended up with 

an 18" airprop driven by a 360 kv motor, that gives a thrust of about 1300grams.

With that configuration,  i made speeds of up to 8 km/h in the mediterranean sea, even in windy

conditions.

Currently, i am working on a better water propeller assembly, that is capable of 

up to 10kg of thrust.

Feel free to contact me for additional information.

Keep on boating!

Harald

Comment by Carl Stiegler on May 28, 2014 at 8:46am

Harald; Thanks for the info. 

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