Introduction: RC Catamaran Boat + VIDEO
I decided to build a device that could travel along the water at my control and was very stable that I could put a gopro on and take above and underwater photography
...So that is exactly what I built
Hopefully this instructable will guide you through the steps that went into creating this
Note that this was my first project involving RC so forgive my minimal knowledge of the subject
Step 1: Why a Catamaran?
A catamaran is "a multihulled watercraft consisting of two parallel hulls of equal size."
This means that the craft is much wider than a monohull vessel, allowing it to be more stable in the water
It also doesn't need a keel, so it can be in much shallower water
It doesn't need ballast to help it balance, so it is much lighter
Step 2: What You Will Need
I made the catamaran from good ol' 1/2" PVC, used standard RC electronics and RC Boat parts as well as the gopro with a corresponding clamp mount. I added pool noodles onto the pontoons for extra flotation (this proved unnecessary but it looked cool to me!)
The frame:
- 6x 1/2" PVC 45 degree
- 2x lengths of 1/2" PVC
- 4x 1/2" PVC "T"
- 4x 1/2" PVC end caps
- A small plastic tub for the electronics
- 4x 1/4" galvanized bolts to hold the tub onto the frame (washers and nuts as well)
- 2x pool noodles and zip ties to hold them to the pontoons
The electronics
- An RC receiver (I stole mine from an old RC I had lying around)
- the corresponding transmitter for that receiver
- I used an hpi 15 turn brushed motor for this project and corresponding ESC I got from ebay for $15A
- servo for the rudder
- Batteries and charger (I ran two NIMH batteries in parallel for longer run times
The other hardware
- A "U" clamp of corresponding size to the diameter of your motor
- A thin steel rod to use as a prop shaft
- Orange paint
The Boat Stuff
- An RC boat prop (got mine from amazon)
- A small plastic surface to act as a rudder (and the means to connect that to the servo)
Step 3: Put It Together
I'll mash the actual construction of the thing into one step because it's not complicated at all
I don't expect you to follow exactly what I built (I wouldn't!) so please make your own variations and let me know about them in the comments
What I did in a nutshell:
- First, glue together the PVC frame as shown and paint it if you want
- Attach the plastic tub to the frame with the nuts
- Drill a hole for the prop shaft to go through and holes for the "U" bolt motor mount
- Attach the motor inside the U bolt and tighten it, connect the motor shaft to the prop shaft and put the prop on
- Install the servo and the push rod for the rudder along the prop stabilization bar (Pic 3)
- Connect all the electronics together
- Attach pool noodle flotation device with the zip ties
- Drill a hole for that receiver's antenna and you're ready to roll (float)
Oh, and put that gopro on there somewhere
Note: If you are using your catamaran in water that is not clear, paint the prop orange that way if it gets detached somehow, it will be visible (it has actually happened to me)
Step 4: Finished Product
The project took some tests and tuning, but after a little time getting it to work, I had a nice vehicle and got what I wanted
Thanks for reading and I hope you made something similar (probably better)
Step 5: Video
The video shows the catamaran's basic functions, in the future I will make on-board videos
Attachments

Participated in the
Photography Tips and Tricks Contest
17 Comments
6 years ago
Hi, My friends and I are making a similar boat for our school science fair and had a few questions. We are using two motors and are wondering how to connect the motor to the motor shaft. We were also wondering if it would be possible to make a prop ourselves and if so how. Thanks
Reply 6 years ago
hello, I used a shaft connector with two set screws in it. if your propshaft is going to be long like mine, use u joints. as for diy props, it is possible but they will likely be less efficient
Reply 6 years ago
Thank you
7 years ago
Love the idea - think I found my first summer project!
Reply 7 years ago
Awesome! make sure to post it when you finish
7 years ago
is there a weight limit of what it can carry?
Reply 7 years ago
The weight limit is a function of the volume of the pontoons. The volume x the cubic unit weight for water of the same volume is your load capacity. Need more capacity? use larger tubing for the pontoons/hulls
Reply 7 years ago
I'm sure there is a weight capacity of somewhere around 3-5lbs, with a watercraft, payload becomes less of an issue because it will still move almost regardless of weight, just at a lower speed. Also, having it being a catamaran means the payload is more evenly distributed, making the craft more stable and able to take heavier loads.
7 years ago on Introduction
Nice build, do you have any pictures/video of it in the water?
Reply 7 years ago on Introduction
I too was eager to look at the video.
Reply 7 years ago
video is up
Reply 7 years ago
I've actually disassembled the cat since I wrote the instructable, I can put it back together and take video if you want
Reply 7 years ago on Introduction
If you get a chance. I wanted to see how well it works in the end.
If you took it apart. Are you scraping it for a better build?
Reply 7 years ago on Introduction
Video is up
Reply 7 years ago on Introduction
Nice thank you. It moves around better than I thought it would. I am impressed.
Reply 7 years ago on Introduction
Thank you sir!
Reply 7 years ago
Well...I needed the motor and other parts for other projects that can't really be compared to this... different purpose
I'll get it put back together soon and post a video