homemade rudder steering problem

[jdory]

Home made boat.

I've got a tiller that turns a quadrant up in the cockpit. The quadrant has dyneema leads to a car mounted on a track on the back bulkhead of the catamaran. From there, rods go to the tiller arms on the rudder shafts. I'm hoping I can make this work.. but as the rudders are turned, the arms on the rudder shafts rotate a bit and bind up on my attaching hardware. Images can explain better. But if I tighten down the rod to tiller hardware (forget what those with the captive ball are called), it limits the travel of the rudders because it binds up. One image shows the bolt with threads showing on the bottom at neutral, then the other image shows the bolt tight when turned. If I tighten the bolt at the neutral position, it binds earlier in turning.

Perhaps I could get a longer bolt and capture it top and bottom of that tiller arm with a nut on top and one on bottom of the arm, with enough free shaft of bolt above to allow non-binding. That increases the strain a bit on the rudder arm bolt hole, but maybe ok.. I don't know.

One image shows how much the rudder can turn as is.. which might be enough? Again, I don't know. (I'm a complete newb here). That is when it binds on the arm.

Question is if folks can think up a better solution given what I'm trying to do.. could be something very simple I'm overlooking. Hate to do a complete redesign.

I'll be traveling this coming week so may be a bit quiet if anyone has questions.. I'll look again later today and tomorrow, then I'm heading out of town.

 

[HelmutSheina]

I only have a phone here so my lines were drawn by finger. I am trying to demonstrate how the angle between the bolt and rod end are too extreme, hence binding at hard to port.

If a perpendicular bracket were fitted to the tiller where the rod end is (eg short piece of aluminium 90° angle) so that it could rotate, and the rod end fixed to that with a horizontal bolt, it might work.

 

[montero]

How does this arm make such a large angle?
Is the axis of rotation vertical or canted?
There are large-angle joints, but they're expensive off-road toys.

I would connect both arms horizontally with a single rod. I would add a central pivot. But you probably want a motor there...

 

[jdory]

How does this arm make such a large angle?
Is the axis of rotation vertical or canted?
There are large-angle joints, but they're expensive off-road toys.

I would connect both arms horizontally with a single rod. I would add a central pivot. But you probably want a motor there...

The rudder shaft is canted.

 

[jdory]

I only have a phone here so my lines were drawn by finger. I am trying to demonstrate how the angle between the bolt and rod end are too extreme, hence binding at hard to port.

If a perpendicular bracket were fitted to the tiller where the rod end is (eg short piece of aluminium 90° angle) so that it could rotate, and the rod end fixed to that with a horizontal bolt, it might work.

That is something I can probably mock up and give a try.. see how it goes. Thanks for the suggestion!

 

[montero]

You can also use ropes and pulleys, then you have more freedom of angles.

 

[montero]

That is something I can probably mock up and give a try.. see how it goes. Thanks for the suggestion!

But you still need ball joint rod end . What about salt water ?

 

[jdory]

But you still need ball joint rod end . What about salt water ?

They are stainless steel.

 

[HelmutSheina]

I have to give Montero Engineering credit for this idea, which might just give you enough movement.

Best of luck

Ball Joints - Stainless Steel - Shop Now Zip Pay | Tamar Marine

Stainless steel ball joints with a spring loaded ball receptor provides quick release.

tamarmarine.com.au

 

[gonzo]

What is the reason not to have a straight bar between the tillers? If you connect them with a single bar, the dyneema lines can be attached at any point.

 

[jdory]

I have to give Montero Engineering credit for this idea, which might just give you enough movement.

Best of luck

Ball Joints - Stainless Steel - Shop Now Zip Pay | Tamar Marine

Stainless steel ball joints with a spring loaded ball receptor provides quick release.

tamarmarine.com.au

I'll have to look into how these are used.

 

[jdory]

What is the reason not to have a straight bar between the tillers? If you connect them with a single bar, the dyneema lines can be attached at any point.

An earlier launch with a different steering system that I was trying to avoid because of the inability to access the newer transom hatches. But it shows why no bar across.. the outboards.

 

[jdory]

 

[SolGato]

There are a few ways you may be able to increase articulation.

You can use a larger joint, undersize your current pivot bolts and sleeve your existing joints, or if you only need a little bit, make a stand-off for the top and bottom so that the corners of the hex head and the lower mounting surface don’t interfere with the heim joint body before the OD of the pivot bolt does.

It’s hard to tell from the photos how much additional articulation you need.

 

[gonzo]

An earlier launch with a different steering system that I was trying to avoid because of the inability to access the newer transom hatches. But it shows why no bar across.. the outboards.

You can still use a single bar. It will need to have some curves to get around the outboards though.