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[LogoFreak]

Hello everyone,

I got the boat hauled out a week ago to do some bottom work and a few other projects. One of them is installing a new raymarine ev-200 below deck autopilot, I dropped the rudder today but couldn’t pull it out completely as the boat is just not quite high up enough. Removing the radial drive was a PITA, 3 out of 4 bolts snapped, was enough to release the pressure though and I got it out in one piece. Took it home to take it apart, got lucky and was able to drill out the 3 bolts that snapped. It shows a fair bit of corrosion but won’t know for sure if I’ll re-use it until i soda blast it.

I’m having a fab shop make me a tiller arm for the autopilot, 1” aluminum plate with the same bore hole as the radial drive and a coupe of 3/8in bolts should do the trick. Playing around with the idea of using the tiller arm as “clamp” around the radial drive, not sure I’ll bother with that idea though.

The second part of the equation is going to be glassing a mount to the hull for the linear drive to bolt on to, can’t start on that till the tiller arm is built though. Going to make a jig that will bolt on to the tiller arm at 90° on one end and the other end will have 4 holes on it to show me where on the hull I need to make the mount.

[Noah]

Did you check Edson for a tiller arm?  That is where I purchased mine. They are expensive—$400+ but are engineered for the purpose and your rudder post.
Also, make sure your hull mounting is super-solid/bulletproof. I have a Simrad (ex Robertson) electric/hydraulic autopilot that I am currently in the process of re-engineering and remounting after it self-destructed recently, ripping off the hull—after four years of use. My ram generates up to 750 lbs of torque—which was too much for the the old engineering/install to take. Hopefully, not this time around. I have beefed up the hull around the mounting location with a 1-1/2 in. solid oak landing pad sandwiched between 11 layers of biaxial fiberglass and epoxy— topping that with a stainless steel pedestal to mount the ram. I have completed the fiberglass work and the pedestal is at the welders. Once back up and sailing I will post pics. Good luck with your install.

[LogoFreak]

Yes I’ve considered the Edson tiller, overprice in my opinion. 1” thick plate cut to the right shape is all I need. As for the mount for the linear drive I’m 100% with you, making the shape of the block out of foam, placing a 1/2 plate on top of it and glassing the whole thing to the hull. It will be fully encapsulated from all sides and glass will extend a good 4~5” all the way around. Once cured I’ll drill and tap the aluminum plate under the glass and bolt up the ram.

[Noah]

How do you intend to attach your tiller arm to the rudder post?

[KWKloeber]

You might (or might not) find this thread interesting...

https://groups.io/g/Catalina30/topic/under_decks_autopilot_on_92/76086704

Especially the links in msgs Aug 24 #106722 and Aug 26 #106740 to the finished product

[LogoFreak]

How do you intend to attach your tiller arm to the rudder post?

1” plate water jet cut to the shape I show in the last picture.

[Noah]

Are you bolting to the radial quadrant or to rudder post? IMO (and Edson’s I believe who made the quadrant and C34 steering system) the tiller arm needs to capture/clamp around the rudder post and pin horizontally through/to it. Not vertically bolted up or down through the radial quadrant. Not strong enough.

[LogoFreak]

The way I have it pictured would be just as strong, it’s essentially bolted around the shaft, It’s just that it’s also clamping the radial drive. I’ll take a couple of other pictures as it’s hard to understand from the one I posted.

[KWKloeber]

Are you bolting to the radial quadrant or to rudder post? IMO (and Edson’s I believe who made the quadrant and C34 steering system) the tiller arm needs to capture/clamp around the rudder post and pin horizontally through/to it. Not vertically bolted up or down through the radial quadrant. Not strong enough.

Interesting but why wouldn’t the radial wheel be strong enough?  In what way do you mean?
If the steering wheel drives the post thru the radial wheel, why wouldn’t the radial wheel be strong enough to drive the post using the arm?

That said - belt/suspenders - my prior post shows the pics how to bolt to both the radial wheel and the post, and two vids of the finished assembly in action. Not located beliw deck, per se - but in the radial drive chamber on the 30 mk-III.  Same concept, just different location of the radial wheel.

[Noah]

I don’t know the engineering behind the “not strong enough” comment, that came from my previous conversations with Edson and their literature, as well my autopilot and other’s manuals that cautions against attaching directly to radial quadrant and tiller arm should be attached to rudder independently. Perhaps the casting is not beefy enough for continual sheer point loading, not flat enough??? Don’t know. Again not only am I not a mechanic, but not a mechanical engineer either!

[LogoFreak]

The radial drive isn’t strong enough if you’re only bolting the pin directly to a surface of the radial drive, it’s also not possible in my case as the linear drive wants to be 10in on Center between rudder post and its attachment point.

[Noah]

Got it! So solidly “sistering” your custom flat bar stainless arm to the top or bottom of radial wheel/quadrant itself, instead of independently to the rudder post, should probably mitigate the concern of attaching the ram directly to the radial wheel/quadrant.

[KWKloeber]

Sistering is a good way to put it.

https://share.icloud.com/photos/0QszbztMbClwMIfIi_wEbQQFA

[LogoFreak]

Small project update, tiller arm is made, just need to drill a few hole to final size and it’s ready to go.

[waughoo]

Nice!!  So i thought it was going to sister up to one side of the quadrant.  Does it now mount all the way around the rudder post?