Hunter 50 rudder shaft keyway size

[Gianni65]

Hello.

Anyone can tell me what the size of the keyway installed on the rudder shaft of an Hunter 49/50 (3" diameter)?

I'm few hours flight from by boat and need to commission second tiller lever to decouple autopilots and rudders draglinks.

thank you and warmest regards

GM

 

[artboas]

Hello.

Anyone can tell me what the size of the keyway installed on the rudder shaft of an Hunter 49/50 (3" diameter)?

I'm few hours flight from by boat and need to commission second tiller lever to decouple autopilots and rudders draglinks.

View attachment 235737

thank you and warmest regards

GM

I don’t have this dimension immediately available. Sorry
Question..
I’m curious about your comments about second tiller arm. Etc.
Could you kindly elaborate?

 

[Gianni65]

Sure.

I've 4 arms (draglinks), 2 from manual steering (port and starboard) and two from to autopilots that are configured in stand-by / active mode, manually selectable by a switch.

Packing all 4 rod ends in the same pin represent a single point of failure so I'm working on several ideas to divide pilot/manual steering or pilot/pilot, manual/manual; one option is to put an additional Lewmar TL10 upside down with respect to the existing one, second option is to machine a plate with 3 bores, one central for the manual steerings, to lateral for the pilots and divide the rod ends with manual steerings centered on the TL10

Today both pilots' rod ends are single AISI 316 M10 bolt which has already broken twice over 2 years, last one 10 days s ago about 30 nm from Casablanca with F6 sea.

Any idea how to reach redundancy is welcome !

With my warmest regards,

G

 

[artboas]

Sure.

I've 4 arms (draglinks), 2 from manual steering (port and starboard) and two from to autopilots that are configured in stand-by / active mode, manually selectable by a switch.

Packing all 4 rod ends in the same pin represent a single point of failure so I'm working on several ideas to divide pilot/manual steering or pilot/pilot, manual/manual; one option is to put an additional Lewmar TL10 upside down with respect to the existing one, second option is to machine a plate with 3 bores, one central for the manual steerings, to lateral for the pilots and divide the rod ends with manual steerings centered on the TL10

Today both pilots' rod ends are single AISI 316 M10 bolt which has already broken twice over 2 years, last one 10 days s ago about 30 nm from Casablanca with F6 sea.

Any idea how to reach redundancy is welcome !

With my warmest regards,

G

Hi there
I’m a bit confused
The 49 /50 Lewmar steering came with the ability to bolt on an integrated motor unit directly onto the starboard steering gearbox,
This is an incredibly solid setup with zero backlash
It sounds as though you are trying to integrate Raymarine linear pilot drives instead of the intended Lewmar solution.
I agree that loading up 4 steering arms onto one rudder link is not mechanically sound.
I suggest using the Lewmar drive I’m surprised you don’t have one already installed

 

[Gianni65]

Hello.

When I bough the boat, back in late 2022, it was equipped with a Raymarine actuator and I thought this was the standard setup.

Then in summer 2023 the bolt broke and with the service company we decided to decouple the autopilot from the manual steering system, as you can see in the picture (actually 2 Raymarine actuators in stanb-by / active setup).

Then 2 weeks ago, on the route from Gibraltar to Canaries, again: bolt broken, no more autopilot and had to repair in Morocco (now back to Spain).

That's why today I'm looking for a robust solution and I was insisting on the two Raymarine actuators, as you can see from the sketch here attached

And finally you you enlightened me: getting rid of Raymarine actuators and fancy workarounds to make the work reliably and install a Lewmar drive the starboard gearbox, leveraging on the standard H50 steering system. Thank you !!!

I would be very grateful if you could point me to the Lewmar motor you're referring; I've found this Mamba Drive but not sure since digging on the internet there are many options.

Warmest regards,


G

 

[artboas]

Hello.

When I bough the boat, back in late 2022, it was equipped with a Raymarine actuator and I thought this was the standard setup.

Then in summer 2023 the bolt broke and with the service company we decided to decouple the autopilot from the manual steering system, as you can see in the picture (actually 2 Raymarine actuators in stanb-by / active setup).

Then 2 weeks ago, on the route from Gibraltar to Canaries, again: bolt broken, no more autopilot and had to repair in Morocco (now back to Spain).

That's why today I'm looking for a robust solution and I was insisting on the two Raymarine actuators, as you can see from the sketch here attached

And finally you you enlightened me: getting rid of Raymarine actuators and fancy workarounds to make the work reliably and install a Lewmar drive the starboard gearbox, leveraging on the standard H50 steering system. Thank you !!!

I would be very grateful if you could point me to the Lewmar motor you're referring; I've found this Mamba Drive but not sure since digging on the internet there are many options.

Warmest regards,


G



View attachment 235817

Firstly, I’m glad that I was able to help. In all due respect, putting in 2 linear drives is not a robust solution
I now understand why you wanted a backup drive, as one would just be prone to failure

I’m going to ask you to PM me. Perhaps I can help further.
My best

Arthur

 

[Screen Saver]

Just to give context to my response , not to be some smart arse no it all I have H49 2008 from new, I have done roughly 130,000nm, been in 60 knots and 8m sea’s. Like I said I say that only do give prospective. So you mention about Tie rod ends and bolts. Just so Im clear its not the Tie rod ends that are breaking I assume and what you have mentioned about your changes doesn’t change that load on the tie rod end, unless Im mistaken ? So I assume you’re talking about the single bolt through the arm on the rudder shaft. On the H49 i believe this is 12mm not 10mm and its actually a stud where as yours (if original) has arms top and bottom. In itself that’s better than on the H49 where its all on the top. So yes that stud in the tiler arm sheared off on mine halfway on a 600nm passage I was doing solo. So yep I get your pain. That happened at about year 3 of ownership. When lewmar welded the stud in they cut a grove in the stud to give the weld something to hold onto. I understand that’s a standard engineering practice. Anyway it broke right at that point. I eventually drilled it out and replaced with a bolt, that would be the equivalent to the tie rod end. That was some 14 years ago and the only other problem I have had in that area, is the plate the gear box is mounted onto went rusty due to a fresh water leak. So yes there are a number of single points of failure, just like the tie rod end on car, these points don’t normally fail. If you have had that many break I would be wondering about the size of the bolt (from memory mine were 12mm not 10mm), and the angle its being driven at, and whether its hitting the end or limit stop. Some related story telling (not technical) if you're interested while you're having a beer follows.Oh shit what have I done | Screensaver and Home at last | Screensaver