Kayak vectored thruster project

[rogerdodger]

One of the things you learn quickly about using a pedal drive kayak with a rudder is that time and space are required to turn. This is because the rudder needs you to be moving before it can provide any turning force. One way around this is to vector the propulsion, adding an electric trolling motor that turns would be an example, Hobie sells a ProAngler360 in 12' and 14' that use a mirage pedal drive that lets you rotate the fins to change the thrust direction.

Another approach is to add thrust to the rudder, this is what I went with. I added a pair of brushless ROV thrusters to the rudder of my Hobie Outback while still allowing the rudder to retract up under the hull to avoid obstacles.



The build went really smooth, lots of details on parts used are in the video, I ran everything on the outside of the hull, no holes required except in the aluminum rudder from Snipe Air Industries. Using a pair of 12Ahr, 12V LiFePO4 batteries, looks like Pepper and I can go 3mph for probably 3 to 4 hours, plus turn on a dime. (Going to 16V would increase thrust by 50%).

On the water testing starts about 5m05s and I do a '3mph U-turn' about 6m40s, that was real sweet. cheers, roger

PS- any non-human propulsion on any sort of boat in OR requires registration, I would exempt electric propulsion under like 1hp but that's just my opinion, so I went through the process and got mine, not a big deal.

 

[bass]

That is pretty wild. Any concerns that you are over-stressing the rudder mount? It looks like you swapped the plastic rudder for a metal one, but all the force of the thrust is now on the rudder assembly.

 

[rogerdodger]

hey Bass- I was paying attention to that. If you remove the screw in the center of the round thing on the top, with the rudder down, you can drop down the whole assembly (black plastic pivot and the rudder). the pivot is supported as it turns at several locations (I think it is 3) as it runs up through the hull, so it is fairly robust. The next thing I did was mount the thrusters as high on the rudder as possible, while maintaining full retraction when the rudder kicks up. This reduces the distance from the thruster force to the pivot points, a shorter lever arm basically, so they are doing more pushing and putting less off axis stress on the rotating part. Mounting the thrusters at the bottom of the rudder would have created more stress.

So I liked how things looked and on the water the steering performed just the same as it did before, same force was required to turn the rudder with the thrusters running, it also didn't try to turn by itself, the Outback 'drove' just the same. Except it was like having steering on the rear wheels of a car.

 

[bass]

I figured you were careful about that. That sounds like a solid approach. Reducing the moment arm of the thrusters was good thinking!

 

[NKlamerus]

Very well done, been looking at similar setups that run on 24v so I could power them with my collection of DeWalt batteries.

Are you running your other electronics off the same batteries? I watched the video but couldn't listen

 

[rogerdodger]

Very well done, been looking at similar setups that run on 24v so I could power them with my collection of DeWalt batteries.

Are you running your other electronics off the same batteries? I watched the video but couldn't listen

no, I'm running my sonar OFF a 6Ahr LiFePO4 battery, 1.6 pounds, inside the hull. my lights (front red/green and rear all white) are both battery powered from Navisafe/Navilight, the standard GoPro mount on them makes it easy to put them up when needed.

 

[hobster]

Awesome, looks great. Well thought out as usual!

 

[rogerdodger]

Awesome, looks great. Well thought out as usual!

thanks man, just got the new decals applied, some required, some just for fun.

time to go fishing!

 

[hobster]

excellent!

 

[rogerdodger]

follow-up on this project that I am late posting- last July, fishing for ocean salmon out of Depot Bay, I encountered some really strong seaweed that wrapped around the thrusters and jammed the little props. not a problem for inland lake fishing, where I can just head to shore, hop out, and clear the weeds. but on the ocean, I can't really do that and jammed prop = drag.

So I've been running without the thrusters since then, just too busy to fix them but my goal is to have them back online for fall coho at Siltcoos and Tahkenitch later this year.

 

[NKlamerus]

Dang I thought that was some heavy braided fishing line at first!

Did they burn up when they jammed? Or did you just remove them out there to reduce the drag?

 

[rogerdodger]

Dang I thought that was some heavy braided fishing line at first!

Did they burn up when they jammed? Or did you just remove them out there to reduce the drag?

no damage to the thrusters from the seaweed, I pulled them to do a full tear down and cleaning (the powerful magnets in them do a good job of picking up iron containing black sand, unfortunately not any gold). I'm really impressed by them, you can basically replace any of the parts, but I just got so busy I haven't put them back on. cheers

 

[Spoonplugger1]

Since the registration requirements are a federal law and older than all of us and it has served us all well, there really is no need to make things more difficult than necessary and really registering a vessel is no big thing. After all whether we have a vessel and whether or no it is powered are all free choices we make.

 

[rogerdodger]

Since the registration requirements are a federal law and older than all of us and it has served us all well, there really is no need to make things more difficult than necessary and really registering a vessel is no big thing. After all whether we have a vessel and whether or no it is powered are all free choices we make.

My understanding, the Federal law only applies to boats that are operated in 'federally controlled waters', which are defined as:
-------------------------------
Federally controlled waters are waters on which vessels must observe federal requirements, including visual distress signal requirements. These waters include:

• Coastal waters
• The Great Lakes
• Territorial seas
• Bodies of water connected directly to one of the above, up to a point where the body of water is less than two miles wide

https://www.boat-ed.com/oregon/studyGuide/Which-Waters-Are-Federally-Controlled/10103801_44510/
-------------------------------

Oregon requires registration for ALL boats with a motor regardless of where they are operated.
Washington, for example, does not require registration for boats under 16' with less than 10hp motors UNLESS they are operated in Federal waters.
If Oregon followed the same approach as Washington, kayaks/canoes/pontoons under 16' with less than 10hp motors would only need to be registered if they are being operated on the ocean.

I like Washington's approach but I would make it electric (no reg) vs gas (reg required). Getting registered in Oregon isn't a big deal, but the annual cost is more than just the invasive species permit. I would then get needed Marine funds from another source, higher fees on very large/high value vessels works for me. ¯\_(ツ)_/¯

 

[DOKF]

I will probably stick with good old elbow grease for my canoe. Even though the beast is designed with a rear transom for a small motor.

I had dreams of getting an electric to help keep a constant speed, but I guess the exercise won't hurt me. Plus, maybe erratic speeds might be more productive for trolling ..