Manual Trim and Tilt Design

Hi fellas, my last boat had a 25hp outboard with forward steering. One feature I always missed was trim and tilt. I am making a boat at the moment that will likely run an 8 and/or 25hp converted to forward steering. I have been thinking on implementing remote tilt and trim with in a manual until that is also solid and reliable

I have access to 3mm plate stainless steel of a very high quality. I am wondering about making a motor mount bracket like I have drawn up with. Also making a lawn mower height changer levery into sloty thingy (sorry down know what that mech is called) and connecting the two units with a tie rod made from the same steel



Of course the dimensions and lengths of lever/fulcrum points and tie rod length well be optimised to extract ruggedness and balanced with minimal weight design

Would like to hear your thots on this and also if anyone has implemented anything like this and your results, thanks

 

I should mention that I am making a low tunnel box thingy joining my console to the rear deck and this and the control/steering cables will run through that. I dont want to run things under the sole as want that as a sealed unit while still being able to service the cables and such. Much like the transmission and drive tunnel in RWD car

 

If anyone with awesome CAD skills find any merit in this, can you please render a 3D image of this?

 

The tie rod goes through the transom ? Won't you have water ingress ? Your motor swivels, how do you cater to that ?

 

The slot in the transom would be high up above the water line and its a high sole and self bailing. Also a boot from a car rack can be used

Existing motor mount on the motor to be bolted onto this mount. Just like any aftermarket power trim/tilt unit. Why would the motor swivel be affected? That doesnt make sense to me?

 

OK, now I understand, you are making a tilting bracket, and the motor will fit to that.

 

Thats the one! Would really appreciate some help from those in the know to troubleshoot and refine the concept. Especially some curious overthinking bugger like myself but who has easy access to scrap and metal cutting equipment and plenty of time on their hands to make a mockup to see if it works. For me I can do it but it will be painful as I am not equipped for metal work

 

Too big a job to be fabricating something like that from scratch, I am not sure why you need it.

 

Another thing I was looking at is a hydrolic jack, one of those little red thingys used to change tyres. maybe I can fit that to actuate the motor plate and the tie rod can then simply be used to pump and not need any locking and such

I have only driven one boat with power trim and was very impressed with the ability to adjust to prevailing and load conditions on the fly. I have looked at getting one of those CMC units but too pricey and heavy so shipping will be very high. Wont give up on the feature unless it proves to be too difficult to implement

 

The concept will work but:
You have the control rod working in compression and that will be a problem. If you put the pivot at the bottom, the thrust will be on that and tension will be on the rod at the top where it can be handled more easily.

Some more thought may turn up a better system but this is a starting point. I like the ability to remotely tilt a smaller motor also.

 

Probably a cam to make the movement will take all the pressure off the control rod and the cam can then be at the bottom as you now have it laid out. You would need a spring to maintain the bracket in its proper place and allow for reverse.

 

Almost all outboards come with a tilt mechanism built in, why not design a cam that will fit into the existing system?
Harbor Freight or Grainger catalog has a huge selection of hydraulic goodies that you might be able to use in order to eliminate the cumbersome mechanical actuator/linkage.

 

Why bother with that mechanism? The motor already has a tilt adjusting system. Find the right one for whatever the boat load happens to be. It is then a matter of selecting the appropriate pin hole. The experiment that reveals the right tilt angle will take maybe an hour of experimentation. That is a lot less time than will be required to build some sort of auxilliary device.

OK if you are hooked on gadgetry, then go ahead with your idea. It'll work. But why?

If you might use a big motor then maybe the 3mm plate is not quite enough. Good enough for the 8 HP motor but getting a little chancey for the 25.

 

Agree. Plus, my hydraulic bottle jack clearly states "use in upright position only". This may be to prevent fluid leaking.

 

That hydraulic jack would stand up well to salt water, NOT !