homemade rudder steering problem

[portacruise]

Sometimes a flexible sheathed SS push-pull cable has solved close quarter and sharp angle issues for me, in addition to some above suggested methods, or separately. Just an idea, discard if not useful.

 

[tropostudio]

Not sure what your bolt size is, but this place has options for SS high misalignment rod end bushings:

Rod Ends / Heims > Rod Ends

Browse our selection of Rod Ends / Heims here at Figspeed High Performance Speed & Marine Parts Shop.

www.figspeed.com

SImilar options from McMaster Carr:

Ball Joint Rod End Inserts

Ball Joint Rod End Reducers

Maybe tolerances don't matter much, but would it be worth using shoulder bolts instead of standard bolts? Standard bolts will be a sloppy fit in a tie rod end, and stuff you don't want moving and wearing may do so. If you use a high-misalignment washer or bushing with a standard bolt, keeping them concentric with the rod end insert will be difficult. Same-size thread shoulder bolts from McMaster Carr:

Same-Size Thread Stainless Steel Hex-Drive Shoulder Screws

 

[philSweet]

@tropostudio beat me to it. Here's another - high angle rod ends.

But there are other problems here and I think you need to rethink the tiller heads. The bolts through the tiller end should be nearly parallel to the rudder pivots. The tiller heads need to be modified to accommodate this and also provide sufficient clearance. Raising the height of the steering rod connection on the tiller would help. I'd fabricate new tiller heads to accomplish all of those things. And don't try to use 100% of the rod end's published angle compliance. If you lessen, but don't zero, the angle of the bolt axis wrt the rudder pivot, you need to compute the misalignment angle at +40 degrees rudder, 0 degrees rudder, and -40 degrees rudder and make sure you can accommodate those.

But as others have already said, I don't like the mechanical arrangement. You should have a single, bulletproof tie rod that connects the two tiller heads with high rigidity. The tiller heads should have an Ackerman angle relative to the blades. And if you continue to use rod ends, make the tillers twice as long and use bigger rod ends. It looks as though it was originally designed for hydraulics. I'm also curious what sort of manual backup steering system you have. You need to be able to fit about a seven foot long manual tiller directly to a tiller head for emergency steering..

 

[Barry]

SolGato nailed this.
So the interior rotating piece, which looks like a ball bearing with two horizontal surfaces. The horizontal surfaces protrude outside the rod end or there would not be any movement when the rod is moved.
So you could buy some washers whose outside diameter is about the same diameter as the outside diameter of the "bearing flats" and put a couple on each side of the rod end
I think that a brass/copper oil drain washer might work or would be close. You can google this to get an idea
If not you would need to machine some (SolGato called it a stand off) ID slightly larger than the bolt, the OD the diameter of the flat diameter on the bearing.
The ball bearing system that Montero suggested may also work but they are limited for angles as well.

Another option would be to use an Allen Head bolt which would reduce the size of the head and possible permit more angular movement.

Alternatively, you could have the aluminum inserts that go into the pipe changed out and new ones re-machined The shape could be the same but the hole that is treaded to take the heim joint would not be co axial with the pipe. Figure out what angle the threaded hole would need to make the heim joint face parallel to the tiller arm face

 

[tropostudio]

@philSweet - Pretty sure the boat is a Kurt Hughes CM design that @jdory built decades ago and is getting back into service. Critiques of this modifcation may be warranted, but he's also working around existing kick-up rudder cassettes and shafts. I'm guessing the rudders are pretty well balanced, he knows the stall limits, and can adjust Ackermann angle by changing strut length and clamping position of the tiller heads . I would have suggested high-range tie rod ends, but don't know of any in SS.

Good luck finishing the project!

 

[SolGato]

This is effectively what I was describing in option 3 of my post.

This joint is oversized and accepts stepped stand-off sleeves that fit the ID of the joint reducing the pivot bolt size and allowing for more articulation.

If the joint is just barely binding, you might be able to simply get away with a sleeve spacer top and bottom.

This would be easy to mock up and test with other materials (like washers as suggested) before committing to finding/fabricating solid 316 bushings.

There is a supplier in CA that I use for 316 bushings like this.

For what he charges, it’s typically not even worth uncovering my lathe to make my own unless I can’t wait for some reason and already have material on hand.

 

[Barry]

This is effectively what I was describing in option 3 of my post.

This joint is oversized and accepts stepped stand-off sleeves that fit the ID of the joint reducing the pivot bolt size and allowing for more articulation.

If the joint is just barely binding, you might be able to simply get away with a sleeve spacer top and bottom.

This would be easy to mock up and test with other materials (like washers as suggested) before committing to finding/fabricating solid 316 bushings.

There is a supplier in CA that I use for 316 bushings like this.

For what he charges, it’s typically not even worth uncovering my lathe to make my own unless I can’t wait for some reason and already have material on hand.

Thanks for the picts. I have never seen these sleeves before

 

[wet feet]

A couple of thoughts;a part of the problem is the height of the central track,could it be lowered to reduce the angle at the rod ends?Secondly,I'd get some lock nuts on the threaded portion of the rod ends to keep everything secure.

 

[SolGato]

Thanks for the picts. I have never seen these sleeves before

I missed that Tropostudio had offered links above to the reducers.

For some reason the links do not open in my McMaster App, they just take me to the home/start page.

 

[Smj1]

A couple of thoughts;a part of the problem is the height of the central track,could it be lowered to reduce the angle at the rod ends?Secondly,I'd get some lock nuts on the threaded portion of the rod ends to keep everything secure.

My thoughts as well, but a lower track may get in the way of the outboards?

 

[gonzo]

My thoughts as well, but a lower track may get in the way of the outboards?View attachment 209456

Instead of lowering the track you can raise the bar. There are several ways of doing that. The simplest is a bar with curves.

 

[tane]

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

a lot of Minitransat boats use "diabolos" from windsurfing masts

 

[montero]

Scavenging marine parts is the way to go . I have 4 of windsurfing masts that I intended to use for crab claw sails.

 

[montero]

a lot of Minitransat boats use "diabolos" from windsurfing masts

Mini Transat Race - Wikipedia

en.wikipedia.org

at the rudders ?

 

[montero]

Thx for this . It's game changer for me.