Free play in steering.

[Leighb]

We have wheel steering via "Teleflex" type cable, I don't know the make of the helm unit or the cable. Only marking on the Helm unit is "MKII Made in Sweden". Boat is a 1978 Storebro.

The wheel is 55cm diameter and there is around 10cm of free play at the rim. This seems to me excessive altho' apart from a couple of sailing boats which would probably have had a different mechanical system I have no experience of wheel steering.

There is no apparent backlash where the cable connects to the tiller arm on the rudder head, and at the helm end the "free" end of the cable moves with the wheel, so am I correct in assuming that the free play may be due to wear in the gearing inside the helm unit?

Is it likely that the only way to improve things is to fit a new helm unit and steering cable?

TIA

 

[PCUK]

If the cable moves with the wheel then any gearing must be OK. Is the outer cable securely held to the helm unit as I cannot see any other place for play to occur if the aft end is secure. Well worth dismantling and checking everything from wheel to steering arm.

 

[BruceK]

If it has a tilt mechanism to it I may have an answer to that as I recently fixed mine which now has less than a cm play in it. Let me know and I'll post up the details.

 

[Leighb]

If it has a tilt mechanism to it I may have an answer to that as I recently fixed mine which now has less than a cm play in it. Let me know and I'll post up the details.

No tilt mechanism but thanks.
PCUK thanks I will check for any relative movement at the helm end. The cable is firmly clamped aft and no movement between it and the tiller arm.

 

[scottie]

Think it's a teleflex uk i.e. Morse D260 and possibly original . Cables came in two options 8" & 12" stroke 12" only for rudders but 8" for drives and ruddersSo as the outer spiral may be worn which along with inner gear and drive shaft slop any play multiplies.
I don't think that the 12" D320 cable has been available for many years now and the D335 would need the connection at the tiller modified and the load would increase you might be better thinking of upgrading to hydraulic at some time!

 

[zt260]

If it has a tilt mechanism to it I may have an answer to that as I recently fixed mine which now has less than a cm play in it. Let me know and I'll post up the details.

I would be interested in your fix as I have a tilt mechanism with play in it

Regds. Ash

 

[Leighb]

Think it's a teleflex uk i.e. Morse D260 and possibly original . Cables came in two options 8" & 12" stroke 12" only for rudders but 8" for drives and ruddersSo as the outer spiral may be worn which along with inner gear and drive shaft slop any play multiplies.
I don't think that the 12" D320 cable has been available for many years now and the D335 would need the connection at the tiller modified and the load would increase you might be better thinking of upgrading to hydraulic at some time!

Thanks, I am curious to know why you think it is a Teleflex uk, as it is marked Made in Sweden?
I will have to do some careful checking to see what exactly moves with the wheel rim, and what only when it reaches the backlash point, will need two of us, one moving the wheel and watching/feeling movement at the free cable end and the other in the lazarette watching the tiller arm end.
I will also measure the stroke.
Would fitting hydraulic be a major exercise? I know nothing about the subject, all my previous boats were tiller steered.

 

[scottie]

Thanks, I am curious to know why you think it is a Teleflex uk, as it is marked Made in Sweden?
I will have to do some careful checking to see what exactly moves with the wheel rim, and what only when it reaches the backlash point, will need two of us, one moving the wheel and watching/feeling movement at the free cable end and the other in the lazarette watching the tiller arm end.
I will also measure the stroke.
Would fitting hydraulic be a major exercise? I know nothing about the subject, all my previous boats were tiller steered.

Teleflex like a lot of pre WW11 UK companies was a world wide entity that sold off the foreign companies in this case the US company which traded as Teleflex Inc this causes confusion as both marked steering systems of virtually identical design
The Swedish company was retained by the UK organisation.
Morse bought out the UK company in the 60s but they in turn were merged into a group that included both Teleflex lines and TX the other major control manufacturer sometime in the 2000s.

 

[About Time]

Leighb does not say if this is a thing getting worse for him.... The Morse D260 is known to have 7-10cm slip in the steering wheel. This is a common thing with old cable steering. The newer generations of steering hubs with rotary planetary design (made by both Uflex and Teleflex) are much better (less slip). You can google rotary planetary design or look up a video on youtube. In fact I started another thread about this topic as I am about to change my D260 Morse system in my Windy 37 to a Uflex T91 as the slip in the D290 makes me crazy.

 

[BruceK]

I would be interested in your fix as I have a tilt mechanism with play in it

Regds. Ash

Apologies to OP for a bit of thread wander but for Ash's benefit:

If you have a height adjustable steering wheel on Teleflex cable with hydraulic assist there is a (for want of a better word) a UJ clamp that has 2 screw in bolts. 1 tightens to the stub on the rotary mechanism and the other round the steering stub. These can work loose and increase play

You can see the "UJ" in the centre here

The two bolts that need adjusting

Remove steering wheel cap.
Undo bolt and slide steering wheel off being careful not to loose woodriff key.
Slide bezel off.
Remove housing cover.
Rotate steering shaft until the bolt screw heads are visible underneath.

Balance tighten both. I.e if one is over tightened the other will be loose when tightened.

 

[Leighb]

Teleflex like a lot of pre WW11 UK companies was a world wide entity that sold off the foreign companies in this case the US company which traded as Teleflex Inc this causes confusion as both marked steering systems of virtually identical design
The Swedish company was retained by the UK organisation.
Morse bought out the UK company in the 60s but they in turn were merged into a group that included both Teleflex lines and TX the other major control manufacturer sometime in the 2000s.

Thanks scottie that is most interesting and informative.

About Time, The free play has not changed in the year I have had the boat, but I think I am getting more irritated by it!! Also I am thinking of installing an autopilot system and one of the options may be a replacement hub with an integral autopilot motor, hence I am trying to find out more about the existing system.
I need a Simrad autopilot to work with my chart plotter.

 

[About Time]

If you do not have tilt steering and it has not gotten any worse over the years I am sorry to say that this is normal for the old D290 steering hub. Take a look on youtube about the new planetary gear design.

https://www.youtube.com/watch?v=Xs-tYV0eNvg

I will change my old Morse D290 to Uflex T91 (see this link) during winter.

http://ultraflex.ultraflexgroup.com...-high-performance-rotary-steering-system.html

T91 seems to the best cable steering available just now - at least from what I have found. The only 'thing' is that the D290 has a 3.3 turn from Lock to Lock and the Uflex has 4.2 turns from Lock to Lock. I asked if this means anything for my daily use of the boat in a separate thread....

 

[zt260]

Apologies to OP for a bit of thread wander but for Ash's benefit:

If you have a height adjustable steering wheel on Teleflex cable with hydraulic assist there is a (for want of a better word) a UJ clamp that has 2 screw in bolts. 1 tightens to the stub on the rotary mechanism and the other round the steering stub. These can work loose and increase play

You can see the "UJ" in the centre here

The two bolts that need adjusting

Remove steering wheel cap.
Undo bolt and slide steering wheel off being careful not to loose woodriff key.
Slide bezel off.
Remove housing cover.
Rotate steering shaft until the bolt screw heads are visible underneath.

Balance tighten both. I.e if one is over tightened the other will be loose when tightened.

Thanks for that

Regds ash

 

[Leighb]

I have been doing a bit more checking of my system.
The stroke at the tiller end appears to be 12" so presumably I would need to get a replacement with the same stroke, or I would lose some steering angle, would this actually matter that much?
There are 4 turns of the wheel lock to lock, which does not agree with it being a D290?
On more careful checking there is a tiny amount of movement of the cable at the helm end, perhaps a mm or two?

The Simrad autopilot unit that would replace my existing helm unit is said to be "based on the Morse D290" it might therefore suffer from the same free play problem, although perhaps with a new unit and new cable it would be minimal at least for some time.

I am starting to consider replacing with hydraulic, but that looks pretty complicated in terms of what items to get. Any pointers on which firms to consider. I have found a couple of US ones and Phoenix in the UK, the latter has some helpful info on their website but some choices seem vague, for example it asks if the boat is planing or displacement, the semi-D variety not mentioned, it seems to define a planing boat as one with a max speed of 18 knots, the Storebro 31 should manage a bit more on a good day. , so which do I choose?

Hoping for further good advice.

 

[PCUK]

Hydraulic steering is dead easy to fit. Look at Vetus. They supply everything you will need.

 

[Leighb]

Hydraulic steering is dead easy to fit. Look at Vetus. They supply everything you will need.

I had a look at the Vetus website, but found it totally uninformative, just a list of components but no information about what would be needed for a particular application.
Fine if you know precisely what you need, otherwise useless, unless perhaps I am looking in the wrong place?

 

[scottie]

When the torque necessary to manoeuvre a boat is not specified by naval architect nor
by the shipbuilders yard, it can be calculated as follows:-
It must be known that the torque necessary to manoeuvre a boat depends on:
• the speed of the water flowing on the surface of the rudder at a certain angle;
• the rudder size;
• the total sweep of rudder (& a part of the boat) when rudder shaft is not perpendicular;
• the compensating surface;
Torque calculation for a maximum speed about 25 knots:
T = S x [(0.4a) -b ] x V
2
x k
T = Torque in kgm
S = Total surface space of the rudder in m
2
(h x a)
h = Height of the rudder in m
a = Width of rudder in m
b = The value of the compensation in m
V = Speed of the boat in knots
k = Coefficient according to the total angle of rudder
- Port to starboard 50° k = 10.84
- Port to starboard 60° k = 13.01
- Port to starboard 70° k = 15.89
- Port to starboard 80° k = 17.80
- Port to starboard 90° k = 19.52
Straightening according type of boats:
- For boats equipped with jet engine T x 1.3
- For power boats with two engines and one rudder T x 0.5
- For sailboats T x 0.5
- For twin rudders T x 2
Example: Assume a rudder with a height of 0.5m(h), an overall width of 0.35m(a) and a
balance of 0.10(b). Maximum boat speed = 22 Knots. Port to starboard = 70°.
The maximum torque on the rudder blade is given by:
T = S x (0.4a-b) x V
2
x 15.89
T = (0.5 x 0.35) x ((0.4 x 0.35) - 0.10) x 22
2
x 15.89
T = 0.175 x 0.04 x 484 x 15.89
T = 53.9 Kgm Assuming twin rudders maximum steering torque = 107.8Kg
LittleSister
This is one I prepared earlier
You will need to move the mounting for the hydraulic ram nearer to the rudder stock and mount it at 90' to tiller arm