Steering Help Pls

[Fanie]

Hi Guys,

I have desined an electrical steering for a boat. The positioning and control is sorted, but what I need is some kind of a mechanical realese so that if the motor or rudder is forced sideways that it can temporary release without damaging the steering mechanism but continue to function when the side force is removed. Like say when a side wave crushes on the motor or rudder.

The steering mechanism is a motor with a rack and pinnion that drives a push-pull cabe steering the motor or rudder. The mechanical system as is is not forgiving and if forced something could break.

I was thinking of using a spring that will push in or stretch if the motor or rudder is forced. It could work, but the steering may be 'soggy' and will have some loose play sideways. I don't know if this would be a problem.

How can I make a steering that will release under force but that won't disconnect or break the steering mechanism.

Lastly, is this something I should be worried about ? I have never had any damages or steering problems, so if this is not an issue I will use the system as is.

Greatly appreciated.

[cthippo]

Could you use a worm gear drive instead of a gear drive? Then a sudden rudder input would put force on the worm bearing instead of transmitting it to the motor.

Also, what part do you expect will break?

Another though...

What about some kind of electrical clutch that locks the shaft unless the motor is running?

[Fanie]

Hi Cthippo,

It is a worm driven motor I'm using already, only I have a rack and pinnion setup on the output shaft. I can probably push 30 to a 100kg's with it although I haven't tested it yet.

Tbh, I don't know what can or will break, I was hoping any one with such an experience could suggest the weak point.

I will give the electric clutch some thinking over, but the motors may not always be running - it needs to work when sailing too and act as an autocruise. Good idea though, I haven't thought about it. An electromagnet can hold harder or softer as a function of the current through it. If the plunger is a certain length it may reset itself by plunging back into the coil. Drawback is it uses additional power.

[cthippo]

You could also try a spring loaded coil that pushes a block into the gear when not energized. I'm not explaining that very well, but hopefully you get the idea. Do you have a drawing of how this is supposed to work?