Outboard Trim and Tilt Up Limiter

[smallribber]

Because of the layout of my boat I need to stop/limit the power tilt up before it reaches its max position. I cant rely on my letting go of the rocker switch

I only need to do this from the throttle tilt switch not the one on the engine

I recon I can do this in 2 ways:

1) Locate the thin wire from the tilt switch to the relay in the engine, cut this and extend to a waterproof car bonnet type push switch mounted somewhere on the engine that will disconnect the circuit at a particular point in the up tilt,

2) Or do this in the up wire from the relay to the tilt motor. This will be much thicker wireing.

I prefer method 1. Can you see any disadvantages with this method

[smallribber]

This is the relay I have

https://www.ebay.co.uk/itm/285354887...RoCZgMQAvD_BwE

And this is where it is located - (Part No 36)

[smallribber]

Switch I have in mind is somthing like this but mounting will have to be worked out

https://www.ebay.co.uk/itm/364437147...hoChX0QAvD_BwE

I think the spec is:

Normal, Closed Momentary push button waterproof switch. Been searching around and not finding many

[User name]

Originally Posted by smallribber

Because of the layout of my boat I need to stop/limit the power tilt up before it reaches its max position. I cant rely on my letting go of the rocker switch

I only need to do this from the throttle tilt switch not the one on the engine

I recon I can do this in 2 ways:

1) Locate the thin wire from the tilt switch to the relay in the engine, cut this and extend to a waterproof car bonnet type push switch mounted somewhere on the engine that will disconnect the circuit at a particular point in the up tilt,

2) Or do this in the up wire from the relay to the tilt motor. This will be much thicker wireing.

I prefer method 1. Can you see any disadvantages with this method

Is it because of some physical obstruction you want to do this?

Does your trim/tilt relay setup have over-current protection? You can test by holding it all the way down and see if the relay clicks out after a couple of secs when it has bottomed out (just like an electric window in a car).

If it does have it then you only need to physically limit the trim and the relay will cut out itself. You could do that with a steel cable and a carabiner, chain, nylon webbing etc. Basically anything that resists the motor and trips the relay. Am I understanding the problem correctly?

[Orwell boy]

Try checking out honeywell limit switches and microswitches on RS catalogue ,you should find something for the duty with gold contacts or similar which should be pretty rugged for your application ,probhably with the right sort of actuator /roller

[smallribber]

This is the issue I have. The power of the motor will easily break something if I don't release the switch in time. Hence want to cut it off at the appropriate time

[Fenlander]

Don't think I'm being unkind but I'd have that seat swapped or altered by a GRP specialist.

[Davie]

Make a collar the same idea as a 19mm shaft anode from the chandlers. Unscrew the end cap from the centre tilt ram. Clamp collar round the tilt ram to act as a spacer at your chosen height.

[Nasher]

Originally Posted by Davie

Make a collar the same idea as a 19mm shaft anode from the chandlers. Unscrew the end cap from the centre tilt ram. Clamp collar round the tilt ram to act as a spacer at your chosen height.

Surely that will stop it going down as far as it should, not limit the upward movement?
Unless you propose putting it inside the ram body?

It's not that clear in this old image, but I have exactly the same issue with my RIB, and it's actually worse with the 225 Opti I now have fitted.

I've always meant to do something about it, but over the years just remained vigilant when powering it up, and made sure I told anyone else who might do it.

You have prompted me however to have a look at the sender on the Opti to see if I can fool it into stopping early.

[Davie]

Spacer goes in the oil between end cap and piston to dead end the travel on the upstroke.

[smallribber]

Originally Posted by Fenlander

Don't think I'm being unkind but I'd have that seat swapped or altered by a GRP specialist.

I am happy with the seat and its location was where it had to be for the rest of the layout of the Rib. It actually works ok. I may alter it myself and have a plan on how to do it. I am mental busy at the moment and that might have to be next year. It works fine with me stopping holding the trim switch and the amount of up trim is fine for towing. but if I forget one time the power of the motor will break something. I know I chose the wrong seat but it was £1,000 so need to work with it. The switch idea will be quite quick and will work once I can get around to it. Just need a bit of time as my 'part Time work' has gone a little mental at the moment.

[smallribber]

Originally Posted by Davie

Spacer goes in the oil between end cap and piston to dead end the travel on the upstroke.

This sounds very interesting but I am being a little thick and cannot grasp what you are meaning. Is a simple sketch possible ?

[User name]

Originally Posted by smallribber

This sounds very interesting but I am being a little thick and cannot grasp what you are meaning. Is a simple sketch possible ?

Essentially what he's describing is a spacer inside the ram. Rams have end stops on both ends of travel that dictate the max/min travel, and if you add a spacer inside on the full extension side, it'll limit the amount of travel it can do in that direction, but It won't effect the opposite direction.

[smallribber]

Originally Posted by User name

Essentially what he's describing is a spacer inside the ram. Rams have end stops on both ends of travel that dictate the max/min travel, and if you add a spacer inside on the full extension side, it'll limit the amount of travel it can do in that direction, but It won't effect the opposite direction.

That helps but that will involving taking the Ram to bits correct ?

[User name]

Originally Posted by smallribber

That helps but that will involving taking the Ram to bits correct ?

Yep, but they're fairly basic in their assembly so it's not a hugely technical job.

I'd go with a strap, cable etc if you don't fancy getting too involved, but you've done basic carb maintenance on here previously so the ram will be straightforward.

[User name]

I just did a quick google image search for rams while I'm doing nothing.

Excuse the terrible drawing, but I added in blue a crude attempt at drawing a C-shaped spacer. This causes the ram to bottom out earlier, essentially short-stroking it (I had to do exactly this with the boot of my car so it doesn't hit the roof box). You can measure what size of spacer you'll need by marking the ram at the max you want it and then between that point and full extension will be the thickness of your spacer.

[smallribber]

That is an interesting solution. I think I will try the bonnet type switch on the up wire to the solenoid first though. Seems much easier and can easily be removed

[Nasher]

The internal collar is a good idea, but I'd want to check a couple of things on each engine I'd consider using it on.

1) Is the up movement limited by the piston hitting the end of the barrel at the moment?
Or is it electronically limited?
You might end up blowing a seal powering the piston against a stop.

2) In the same way really, the piston might rise until it uncovers a relief valve stopping the movement, with the same danger as above if that valve doesn't get uncovered.

If it simply stops by hitting the end of it's physical travel as standard you are good to go.
I believe this is the case on most engines by the way.
.
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[User name]

Originally Posted by smallribber

That is an interesting solution. I think I will try the bonnet type switch on the up wire to the solenoid first though. Seems much easier and can easily be removed

Just be cautious you're not interrupting the flip-flop circuit or you might find that the limit switch will also lock out the down movement too. Take detailed pics before you start so you have something to fall back on.

[tinker]

Some cylinders have a cushion circuit built into the final part of the stoke, this collar would disable that cushion, it would also displace some of the hydraulic fluid on the up stroke, but the fluid would be needed for the down stroke , which needs more fluid as it hasn't got the rod in the hydraulic circuit.

Far better using a N/C limit switch in series with the raise switch. Just make sure the switch is upto the job of being exposed to at least IP67.