cable steering question

[grafozz]

I replaced the twin cable steering helm and cables on a twin rudder cat last winter as there was around 35 degrees of play in the system and it was playing havoc with the autopilot .
I am finding almost the same amount of slack appearing now in the new system . I have been right through all the clevis pins , cable mounts, bases , everything , and its all in excellent shape .
So it has me wondering where this play could be ?

At present the cables enter the rotary helm on opposing sides , now , by transposing one of the rudder arms to the other side off the rudder stock , which is possible , it would allow BOTH cables to enter on one side of the helm and make one push and one pull as it does at the moment with the cables entering on opposing sides .
The theory behind this is that the play would only be on one side at a time and cut the play by 50 % ?
Am I getting too desperate ? or can cable steering work in this way too ?

Help !

 

[scottie]

When you refer to a cable system pushing I assume that you mean a teleflex spiral wound system as a wire system must be pull only!
The teleflex system is more efficient also if it's pull pull.
Do you have twin rudders if so do you have a tie bar?
You should be able to tension out the slop with the tie bar
So more info please!

 

[grafozz]

cables

Scottie , thanks .
The boat has twin rudders being a cat , one cable 7.2 M the other 4.2M long .
One pulls while the other pushes as it is a twin cable helm .
The cable ends go straight on to rudder arms which clamp onto the rudder posts. no tie bar its all inside the hulls
This gives me no areas of adjustment , I can see the inner cables moving in / out of the outers , showing the play .

 

[nimbusgb]

Play in the cable inners? Check out the runs of the cables with a load on and see if the whole cable is moving about significantly. Locking the outer cable in place may help.

Also the end piece that locks the cable outer to a bulkhead or tang somewhere may be pushing/pulling through the fitting

 

[whipper_snapper]

May I hijack this slightly?

My cat has a very ugly, high friction steering system using rope round a drum on the wheel to pull on two tillers linked with a tie-bar.

Without the rope system hooked-up, the tillers are feather light. With it they are horribly stiff.

I need an alternative arrangement! Wire systems look attractive, how are they 'driven' at the wheel end? Can anyone point me to suppliers and possible system designs ?


Thanks

 

[nimbusgb]

Lewmar, Goiot(?) Vetus, Ultraflex and Morse for a start

For a cat I'd think the very simplest would be an hydraulic system. ( expensive though )

 

[scottie]

So what you have is two separate steering systems working in tandem with a common operating shaft and drum each attached to its own rudder ?
Is it a teleflex system with a splined shaft running inside a splined drum?if so you may find that removing the cables and rotating the drum so that when back in the mid travel position the shaft is working on the opposite portion of the drum which may be less worn than original area of wear.
Was the whole system replaced or just the cables?
The only thing you can do with the cables it to ensure that the runs are as straight as possible with short bends rather than a long sweep which increases drag etc
if the cable sags then support it with a tray if you can
You may be able to take some backlash out by adjusting the the toe in /out to put some load on the tillers but this would take experimentation to see how it was affected by speed.
I suspect that you may improve it but curing it may not be the end result.
Other option is tho contact other owners builder etc.

 

[whipper_snapper]

Lewmar, Goiot(?) Vetus, Ultraflex and Morse for a start

For a cat I'd think the very simplest would be an hydraulic system. ( expensive though )

Hydraulic would be OTT - I think - for a 35' Wharram.

It looks like the systems you mention are intended to drive wheels on vertical rudder shafts. Because of the rudder design our only option is to push-pull on the tillers or linker. Maybe the teleflex sytem referred to here could do it.

Sorry OP! I am messing-up your thread. My needs are similar to yours except that the rudders are linked which makes life easier.

 

[scottie]

Teleflex system may be obsolete and hydraulic not much more expensive option.

 

[bigwow]

Hydraulic would be OTT - I think - for a 35' Wharram.

It looks like the systems you mention are intended to drive wheels on vertical rudder shafts. Because of the rudder design our only option is to push-pull on the tillers or linker. Maybe the teleflex sytem referred to here could do it.

Sorry OP! I am messing-up your thread. My needs are similar to yours except that the rudders are linked which makes life easier.

If you want to loose all feel go hydraulic. Easiest for you would be a sprocket and chain behind the wheel then wire to your tiller cross beam. IMHO