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Fishing Kayak Project(s)

(Philip Krug) #1

This is my fourth iteration of motorizing a fishing kayak. The motivating force behind these projects are mostly related to my desire to “build stuff”. I am a ROF (Retired Old Fart), and projects like these keep me busy and my brain exercised.

My fishing kayak is a 10’ NuCanoe Frontier. . There is a lot of background info HERE.

My first three designs used standard off the self Minn Kota trolling motors. Most of my designs used the Minn Kota Endura C2, a 30 lbs thrust motor that retails for about $100. I bypassed the stock 5 speed forward/3 speed reverse speed control with a Pololu 18v25 Simple Motor Controller. This PWM motor controller has two main advantages. It provides infinite speed control (fwd/rev) and it is very efficient which means much longer run times over the C2 stock 5 speed forward/3 speed reverse speed control.

I have three functions that I want to control “remotely”. Motor tiller tilt, motor/tiller direction and motor speed. My “remote” control functions are all hardwired. All the control functions use basic programable RC components. I have experimented with wireless remote control but since my kayak is very small, a hardwired solution is much easier and has less “moving parts” to fail. :wink: I considered wireless control of my fishing kayak because I wanted to be able to use my kayak remotely to fish, but it turned out that any sort of “unmanned” fishing is illegal in the State of Oregon.

Basic design diagram HERE.

I stumbled on BlueRobotics a few months ago and was intrigued with the T200 Thruster. After reading some of the BlueRobotics thruster applications on “surface vehicles” I thought the T200 might work on my kayak.

Using a handful of ServoCity components I put together a transom mounted setup using the T200 thruster for my kayak. The bottom line is the T200 thruster works great on my kayak.

My concern was the current (battery draw) vs the speed of the kayak. I knew what my Minn Kota C2 setup performed and the T200 thruster design outperformed the C2.

The biggest speed limiting factor with my 10’ NuCanoe Frontier kayak is the hull design of the kayak. I have tried 30 and 40 lbs thrust trolling motors on my kayak and speeds of 3 MPH are a real stretch.

The T200 thruster is rated at about 8 lbs thrust on a 12 VDC system. HERE is a simple graph of current draw vs speed for my latest version using a single T200 thruster. Hopefully, soon I will have similar graphs for a 30 and 40 lbs thrust motors on my kayak.

I have a few things to clean up with is latest design, mostly related to integrating the controls into my current setup.

My next project is to use two T200 thrusters mounted “outrigger” style to propel and steer my kayak, “skid steering”. The mechanical aspects are simple and it appears there is a lot of info related to “skid steering” on this forum. Once I get this project underway, I plan to incorporate an auto-pilot system so I don’t have to make manual adjustments to stay on track. I am sure I will be using a lot of technology from the autonomous USV and Drone world.

HERE are some photos of my T200 thruster setup on my fishing kayak.

I have seen some discussions on this forum related to batteries used with surface vehicles. HERE is some info related to the battery I am using with my kayak. This battery is the only battery I have used with all my designs. Battery data sheet is HERE.

It should be noted that all my designs are for use in freshwater. Salt water application is a whole different issue, to say the least.

There are lots of way to power a fishing kayak that are cheaper than my designs but not nearly as much fun in my humble opinion. :wink:

(Adam) #2

Hi Phil,

Great project! I’m impressed that a single T200 is able to get you moving so quickly, especially at only 12V. Most other similar projects I’ve seen have used multiple thrusters.


(Philip Krug) #3

Hi Adam,

As I mentioned it has a lot to do with hull design and I think the NuCanoe folks got it right for a fishing kayak.

If you look at the current vs speed graph you will see where the hull efficiency starts to drop off. At least that’s my theory. Right around 2 mph the current draw vs speed curve starts steepen.

From my original post. HERE is a simple graph of current draw vs speed for my latest version using a single T200 thruster.

As far as kayak hull designs go, there are many designs and each has its tradeoffs. My kayak is designed for fishing and is wider then other types of kayaks, you can stand up in it. Also my kayak is a bit short, coming in at 10’. I also have a transom for mounting a motor. I am guessing that under human power my kayak might not win any races but when coupled with a motor it does very well.

I believe when I take the same data points using my 30 lbs and 40 lbs thrust trolling motors the shape of the current vs speed graph will look about the same.

Lots of folks that want to put trolling motors on fishing kayaks will tend to buy motors with way too much thrust. All they end up doing is spending more money then they have to plus adding a bunch of weight to their setup. A fishing kayak is NOT a bass boat. :wink: In my case I can troll for fish all day on a single battery charge but the getting from point A to B will always be slow.

The T200 is a great motor (thruster) and does exactly what is claims to do, at least with my setup.


(Mark Langille) #4

Great project. We are actually working on basically the same project.
Originally had planned to mount the T200 on the pontoons but since switched to mounting them on the rear. Will be using 2 T200 and using alternate thrust for steering.

(Mark Langille) #5

Here is our original post on the project - Kayak Outrigger Project

(Mark Langille) #6

Planning to mount the T200 via a Scotty rod holder mounted on rear of kayak, will have a inverted Y insert to separate the motors slightly. This allows for it to be raised and lowered easily via the rod holder.

I’m glad to see you were able to get sufficient thrust from jsut one T200.

We are going to try 2 and also run from 5S Lipos at 21V max power level.

Just have to finish off the coding and controller setup on an arduino for testing and wait for the ice and snow to melt to test.


@pakoregon I love this project, particularly the design and engineering that has made it happen.

I wonder how the efficiency would improve if you had 2 T200’s?


@schoonerlabs You have a lot of real estate for solar panels there, any thoughts?

(Mark Langille) #9

For automated control and guidance, you should be able to use a Pixhawk setup with GPS/compass and do basic heading hold and similar. You could also do full waypoint planning using a tablet and the mission planner/Tower software.

(Mark Langille) #10

No plans for solar for now anyway. Initial plan it to run dual Ryobi ONE+ packs and see how they last.

(Philip Krug) #11

I don’t think adding additional thrust will improve efficiency if my assumption that efficiency is more related to hull design then anything else. When I look at Mark Langille’s @schoonerlabs kayak I see hull that was designed more for speed then stability. I am guessing that if we put my single T200 thruster on Mark’s kayak that the current vs speed curve would look different. The current vs speed curve might stay linear way past the 2 MPH mark that is shown for my fishing kayak. If for example the current vs speed curve stayed linear all the way to the max output of a T200 thruster then adding an additional T200 thruster might prove beneficial and extend the linear portion of the curve.

As I mentioned previously in my reply to Adam’s comments,
“I believe when I take the same data points using my 30 lbs and 40 lbs thrust trolling motors the shape of the current vs speed graph will look about the same.”


(Wayne Langille) #12

How far down from the surface do you think the motor should be. Yours look to be down quite a bit.

(Steve) #13

I am also using T200’s for a personal watercraft. I had started with Minkota. but the brushed controllers were expensive and the total weight sucked. I then switched to a small jet with a brushless motor, but all of the water cooled components were a hassle to plumb. A jet was also way less efficient at my low speeds. My quick mental calculation is that you couldn’t exceed 7-8 knots. Getting threeMPH with one T200 and a lead acid battery is fantastic. I now use four T200’s For my project and use them to steer without a tiller. BTW, there is a max hull speed unless you’re planing.

Using Lithium will save you a lot of weight and increase your power due to it’s flat discharge voltage. I make my own 144 AH packs with commercial cells and BMS. I saved 40 lbs over AGM/SLA. I recently added a fuel gauge that counts amps in/out. I use an Arduino to control everything.

Last summer, I designed and sold a drop-in jet module. I developed three types of throttles for it. There was a wired push button, a hall-effect twist throttle and a wireless 2-speed switch. Since this was for a rider that stood, I wrote S/W to ramp up/down throttle changes to make it less twitchy,

I’m also in Oregon (Hillsboro) and a ROF too. I love visitors. https://www.facebook.com/mantaraywatercraft


(Steve) #14

It would take days to recharge the battery with solar. Two years ago I saw an electric dinghy motor with a 1 sqft solar panel on top of it. The salesman claimed you’d never have to charge the battery. 1 sq.ft solar puts out about 8-10 watts. If the motor uses 350 watts, an hour of use would take 35 hours to recharge if the sun remained directly overhead. A big panel doesn’t radically help, unless it’s on the roof of a houseboat and motorized to follow the sun. I hope we can solve this someday.

(Philip Krug) #15

Update on single T200 fishing kayak setup.

I have removed the tiller tilt linear actuator setup and replace it with a Bansbach Gas Spring damper. It is rated at 7 pounds of force. This allows the tiller to stay in place in both the reverse direction but if the tiller and/or thruster hits something the tiller will lift up.

I replace the winch servo gearbox setup with a “waterproof” servo.
HS-646WP Waterproof Servo (Standard Size)

Also, I had some lengths of carbon fiber tubing so I thought I would replace the tiller and thruster drive shaft on my previous version with carbon fiber tubing. Not sure the reduction in weight is really worth the cost of the carbon fiber tubing but since I had some I couldn’t resist. :wink:

The bottom line is this new version weighs in at 5.3 pounds.

Latest version HERE

I am about ready to test out a 2 T200 thruster version using passive vectoring (skid steering). Hopefully, it will work out and I will have something to show for the effort. This is a proof of concept version using ServoCity components and any final version will look a lot different.

Ducted Propellers - Today’s Rabbit Hole
(Aliasgar Calcuttawala) #16

Hello Philip,

I was looking at your post wherein you had a weed gaurd fixed to the T200 thrusters, I was really a nice idea especially since I was also looking at some thing like that for my project. I have concern on the following?

  1. How was the water inflow and thrust effected by using a weed gaurd? did it decrease or were there no change ?, please inform,
  2. What was the maximum speed you could go with the use of two T200 thrusters?
  3. Did you design the weed gaurd yourself or is it available readily? if possible can you share the CAD file?

Aliasgar Calcuttawala

(Philip Krug) #17

Hi Aliasgar,

For my use, I could not tell if the weed guard(s) were affecting the thrust of my T200 thruster(s).
I am going to do a static thrust test on the T200 thruster with and without the weed guard. I have all the components to do the testing but just haven’t gotten around to it yet.

The whole one thruster/two thruster issue will depend on several factors. First off your kayak has a defined hull speed which for the most part is defined by its waterline length.
So unless you can get your kayak to plane it is not going to go any faster than its hull speed. :wink:
Also, your current draw vs speed is not linear. For example, with my 10’ kayak I can cruise all day at 1.5 mph and only be drawing 4 amps. If I kick up the speed to 3 mph, I might be drawing 12 amps. Additionally, wind direction and speed, as well as any water current, will affect your speed and current draw.

The weed guards I am using are a design from one of the folks on this forum.
You can contact him at bluerobotics@discoursemail.com and see if he will send you the stl file(s).
I had a local guy to the actual 3D printing.

Hope this helps

(Aliasgar Calcuttawala) #18

Hello Phil,

Thanks for the prompt response. Really look froward to know the effect of the weed guard, do let me know the details after you are able to do the thrust test. In the mean while am also trying to do some CFD analysis just to see how theoritically it looks.

yes for the speed I understand the non linearity, I think I will get a better understanding after am able to run my actual model craft… should be some time in the near future.

As for the weed gaurds, have sent the email and look forward to the CADD files.

Thanks a lot, will get back later…

Aliasgar Calcuttawala.

(Aliasgar Calcuttawala) #19

Hi Phil, the mail sent to bluerobotics@discoursemail.com was returned due to some mail problem…

(Philip Krug) #20

Try messaging him via this forum