Convert cable to drive by wire for outboards - thoughts ?

[Dave_S]

I am thinking of replacing my cable controlled outboards with drive by wire. It will need to change gears and adjust the throttle on two outboards.

The radius required for the cable is too small and the length of cable too long, it makes the controls very tight. Plus the controls are in a fixed location and rarely where you want them, it would be nice to be able to move around the boat with a remote.

I was thinking of stepper motors and program an Arduino type controller to a remote control that could even be used from the dock (hahahaha, not sure I would be game for that, just a thought) I shouldn't have thought of that, now I've got an image of the boat heading off without me

Has anyone done a DIY type conversion for this or for any other function on a boat (steering maybe) - successful or not that would be willing to share some advice. Salt water compatible ?

[Frankly]

I spent 30 years designing this type of stuff for underwater vehicles for the US Navy. Strikes me as a lot of work (electrical and mechanical). Programming a small microcontroller maybe 2% of the effort. Steering easy, just buy and install an autopilot. Stepping motors will faithfully follow a fwd/ reverse pulse train (provided you do not exceed rated torque) but they must be initialized when powered up. DC servos also work. There will be gear reductions, motion translation (motors just go round and round), feedback sensors, couplings, seals, wiring, motor drive electronics, ect, ect. IMO just a bad idea unless you have a DOD sized pocket book or just bored with your life. Get two large dogs and a girl friend, that fwd/ reverse shifting will be smooth as silk .


Frankly

[Dave_S]

Originally Posted by Frankly

I spent 30 years designing this type of stuff for underwater vehicles for the US Navy. Strikes me as a lot of work (electrical and mechanical). Programming a small microcontroller maybe 2% of the effort. Steering easy, just buy and install an autopilot. Stepping motors will faithfully follow a fwd/ reverse pulse train (provided you do not exceed rated torque) but they must be initialized when powered up. DC servos also work. There will be gear reductions, motion translation (motors just go round and round), feedback sensors, couplings, seals, wiring, motor drive electronics, ect, ect. IMO just a bad idea unless you have a DOD sized pocket book or just bored with your life. Get two large dogs and a girl friend, that fwd/ reverse shifting will be smooth as silk .


Frankly

Thanks for your feedback.

I like projects where I learn something new and I hate the existing cable controls so I might find out a bit more. I work in mechanical design and I'm confident I can make the physical side work. In my work I have a basic understanding of simple electrical components and capabilities of electronics including very occasional work with stepper motors but I design how I want it to drive and I outsource the PCB and software that makes it happen. So the electronics and software is all learning curve for me.

I'm interested to hear more about using servo motors, I have been thinking steppers, only because I expected they would be smaller for the same low speed torque.

Is it a good idea to use a potentiometer to determine the position of the throttle and gear selector axel. If so where would I source quality parts for use in harsh environments.

Thanks again.

[BillKny]

Just throwing some things at the wall...

You don't really need to command a specific throttle position, all you need is "add throttle" "reduce throttle" and "hold". Seems like linear actuators would be a possible solution. Let somebody else design the mechanical end of things. All you would need is a speed control for the actuator. Push a lever forward to go faster, further forward goes faster, faster. The center position holds speed, and pulling back reduces throttle. No need for fancy electronic position sensor or other feedback. The feed back loop is YOU. It is a different kind of control logic, for speed control at the helm but very doable.

Even easier for shifting. Just set the travel limit, and add a F/N/R switch at the helm. Easy. A simple limit switch can prevent shifting with the throttle advanced.

For me the real issue with anything like this is examining failure modes and making sure that things can not fail in an unacceptable way, and that there is a usable "limp home" mode.

[zstine]

I have done a bit of arduino work. throttle and shift is pretty easy to do. you need a power source (battery) that can charge from the engine to power the arduino and motors. I would just use servos from the RC industry for throttle. shifting may be too much load for an rc servo and you may need a "shield" which powers the motor vice directly powered off the arduino board. however, since shift is only 3 positions, you could just use 2 solenoids (1 on forward, both off neutral 2nd on reverse) connected to relays run from the arduino.. actually you don't need the arduio at all for shifting, just switches and relays. when the Arduino initializes, you can set the start point for the servo as zero throttle.. I think a weekend and you can have this done.. assuming you know a bit of programming and electronics already . make it fly by wire. not remote control. if you know arduino then this is a few hours of work... and I agree, you don't need any position sensors or feedback loop. keep it simple

[Dave_S]

I thought about solenoids for gear selector but I they might be a bit harsh on the gearbox so a nice programmable speed motor with ramping at each end might be kinder.

I'm new to the programming (2 day YouTube expert now). I bought an Arduino kit and have been playing with it. It seems pretty straightforward-ish.

I'm not sure what drives will fit at the moment, linear or rotary (both are nice for different reasons) until I have a good look and measure the force needed I think the throttle drive motor will be rotary and easily sit under the cover something like a NEMA 11 short motor should handle that but I'll have to measure the effort required for gears, l looked at some NEMA 17 but might need to be 114mm long to have the power and probably won't fit, so maybe a shorter NEMA 23 might do it ? If they won't fit under the cover then they must be linear.

[Bill Seal]

B-17s used cables

[Franziska]

Following, we have the same issue and I'd love to see your progress on this.
I also like the idea of the linear actuators ans F/N/R switch. Sounds doable.

[zstine]

Originally Posted by Dave_S

I thought about solenoids for gear selector but I they might be a bit harsh on the gearbox so a nice programmable speed motor with ramping at each end might be kinder....

I'm not sure what drives will fit at the moment, linear or rotary (both are nice for different reasons) until I have a good look and measure the force needed I think the throttle drive motor will be rotary

I don't think a slow, gentle shift movement is what you want. certainly not a ramping speed. That is more likely to cause grinding gears. these are basically square tooth dogs your engaging and my outboard experience is that easing the shifter results in grinding. I think the quick action of a solenoid would be 'kinder' on the gears. make sure the solenoid stroke matches the shifter stroke and put some rubber bushings in the linkage and it's good to go.


As for the throttle, if you remove the return spring (not needed for servo controlled) the force is almost zero. A cheap $15 RC plane or car servo like futaba S3003 is fine and they are small.




of course you could do this for almost $zero$ with hydraulics... As in a few 'free' medicine syringes from CVS pharmacy and a bit of cheap tubing filled with oil.

a la...

https://www.youtube.com/watch?v=P2r9U4wkjcc

[Franziska]

Originally Posted by Dave_S

I am thinking of replacing my cable controlled outboards with drive by wire. It will need to change gears and adjust the throttle on two outboards.



The radius required for the cable is too small and the length of cable too long, it makes the controls very tight. Plus the controls are in a fixed location and rarely where you want them, it would be nice to be able to move around the boat with a remote.



I was thinking of stepper motors and program an Arduino type controller to a remote control that could even be used from the dock (hahahaha, not sure I would be game for that, just a thought) I shouldn't have thought of that, now I've got an image of the boat heading off without me



Has anyone done a DIY type conversion for this or for any other function on a boat (steering maybe) - successful or not that would be willing to share some advice. Salt water compatible ?

Resurrecting this. Did you ever get this to work?