Thought Experiment: Ditching Kayak Rudder Cables

[Koz]

Sometimes my mind wanders and I wonder "what if..."

 

So today I was thinking about issues I have with my kayak rudder and cables. The steering is rather sloppy with the control handle, and if you try and pull the cable too tight and lock it down your prone to fraying the cable.

 

That got me thinking - has anyone motorized a kayak rudder? I used to fly RC planes and you had the controller transmit and then a receiver on the plane to activate servos for the ailerons, rudder, and flaps. Has anyone tried something like that with hooking up a servo to the rudder control triangle? An RC controller type setup would work perfect because when you let go it returns to the center.

 

Yes, it's overkill, costs more money, and probably isn't practical because you're going to have to waterproof things and tie into your power supply. But that's besides the point. I just wonder if anyone has tried it.

[CountryboyinDC]

It probably would be slicker, and if you're handy you could almost certainly do it yourself.  But I'm suspecting that the cost of the waterproof housing and servo motor, plus the need for a power source, switches, etc. is going to make it a non-starter for manufacturers.  

[Standard]

I've actually pondered that quite a bit while out on the water with my Jackson.  It uses fiberglass rods to control the rudder, and replacing them with a linear servo like this would be relatively simple.  Add a servo controller, build a small box to mount that and some batteries and there ya go.  The linear servo is IP54 rated so if it gets dunked it would probably be toast, but should survive splashing water.

 

[Darth-Baiter]

how powerful do they make those servos?

 

I think I would explore aftermarket cables.  the ones that Hobie uses are like hunting bowstrings.  super strong.  and they dont fray.  

[Bankc]

It would need to be a pretty powerful servo to pull that off.  Most of the ones made for RC planes wouldn't have enough power to keep the rudder in place.  But they do make bigger ones for robotics and industrial equipment that would handle it.  A waterproof linear actuator might be another option, as that allows you more torque with less motor, plus the design would allow the rudder to hold its position without wasting electricity.  Though accuracy with a linear actuator would be more difficult to set up as you'd just control the direction it moves, and not it's actual position without some additional electronics setup.  

 

I run SS cables through Teflon tubes on my kayak.  You could use your old cables to feed the Teflon tubes through the kayak, and then flare out the ends of the tubes with a soldering iron, and secure them in place with some Goop.  Then, feed some nylon coated, stainless steel, saltwater fishing leader wire through the tubes and crimped them down.  I use an adjustable eye bolt on my foot pedals and a pair of Progrip rope lock paracord hooks on the rudder (or trolling motor depending on what I'm fishing that day) to fine tune the length.  The end result is a cable that doesn't fray, doesn't bind, is super smooth to use, won't stretch, and won't break.  

 

Or if you just need cables that don't fray, look at replacing what you have with the coated cables and use two crimps on each cable.  One to hold the loop in the right place, and a second to cover the end of the cable so the end isn't exposed.  That's also what I did.  

[Koz]

3 hours ago, Bankc said:

It would need to be a pretty powerful servo to pull that off.  Most of the ones made for RC planes wouldn't have enough power to keep the rudder in place. 

I was comparing it to the servos on RC planes, that's all. There's a big difference between moving a little piece of styrofoam and a beavertail rudder in the water.

 

Servos come in all sizes, so finding one won't be a big deal. But I thought about this some more and remembered that when my dad passed away one of the things I kept was an RC boat that he had. Now, the boat itself is no use to me for this thought experiment, but the controller could be used. Actually, the receiver attached to the servo could be used as well.

 

The trigger isn't needed, but you get the rudder to move by turning a dial on the side of the controller. You could use that and build a housing for it and velcro it to the hull or a gear track device. Like an RC controller, you could power it the AA batteries.

 

Then you could build a small box at the stern with the receiver and servo and tie that into an existing Lipo battery you're using for electronics or buy one specific for your rudder unit. You'd have to do a little math to determine how much power you're going to draw. My guess is you might want to think about dissipating heat as well.

 

If I get bored this winter I may try something like this.

 

 

[Deleted account]

Yeah, there are all sorts of ways to do it, but a proper cable setup should work well.