Hunter 420 below deck autopilot install...

[knowclew]

Originally Posted by deblen

Is pic looking down on emergency tiller attachment?
If so,could you make a rudder stock extension shaft that is notched to fit over that crosspin & have your ram & new tiller arm in that upper compartment?
Attachment 288008

Yes, that's exactly what that is.

I thought about that, essentially extending the rudder shaft length just long enough to allow for a proper auxiliary tiller arm to be fastened. I only need another inch or so of rudder shaft length to accomplish that. A couple of considerations however:

1) The extension would have to allow the emergency tiller to still engage. Seems easy enough, but then I'm not a mechanical engineer.

2) I remember reading somewhere that AP connection to the rudder shaft should be between the upper and lower bearings/bushes otherwise those parts would wear prematurely. I wonder if being so close to the upper bearing.bush in this instance what the real impact might be.

Love the out of the box thinking!

[knowclew]

Originally Posted by deblen

I don't have any personal experience with this,but it appears to turn a steering wheel?
https://trionics.com/comnav-29010009...able-steering/

This particular model seems to be for smaller sailboats. My 420 might be a wee bit large for this one, but yeah, this is the idea... and within the budget!!

Thanks for the research.

I'm sure there's a reason Lewmar can get $7k for their drop in replacement.

[deblen]

Originally Posted by knowclew

Yes, that's exactly what that is.

I thought about that, essentially extending the rudder shaft length just long enough to allow for a proper auxiliary tiller arm to be fastened. I only need another inch or so of rudder shaft length to accomplish that. A couple of considerations however:

1) The extension would have to allow the emergency tiller to still engage. Seems easy enough, but then I'm not a mechanical engineer.

2) I remember reading somewhere that AP connection to the rudder shaft should be between the upper and lower bearings/bushes otherwise those parts would wear prematurely. I wonder if being so close to the upper bearing.bush in this instance what the real impact might be.

Love the out of the box thinking!

If you mount the back end of a ram to the hull and the piston end to a tiller arm (or quadrant as a tiller arm)-the ram pushes/pulls on the tiller arm connection which tries to rotate the rudder. The rudder has water pressure against it,& effectively "fights" being turned.The result is that the ram pressure will try to push/pull the rudder stock "sideways". This puts extra stress on the rudder stock "bearing/bushing"& could cause excess wear or even breakage,usually at the thru hull point-(read leak.)
One solution is to mount the ram to a 5000 or 6000 series marine aluminum plate. Holesaw a hole in the plate to fit snugly over the rudder stock. Now the push/pull of the ram is balanced by the opposite forces of stock going thru hole in plate. See pics in my post 8.


Your rudder stock appears to be SS tubing. Get a short piece of SS tubing or shafting that will fit snugly in existing rudder stock. Remove the white donut first. Notch this extension to drop down over emerg tiller pin.
Mount ram/plate assy with new extension coming up thru hole in plate.
Don't forget about having extra ext.length for rudder sender/follow up arm & a new pin/bolt for emerg tiller. Put donut in top of ext.


Cheers/Len

[knowclew]

Winner, winner chicken dinner!!

When I'm ready to go the linear actuator route, this is most certainly, the way to go.

To be honest, I didn't notice the genius of what was going on, in your post 8 pics, but now that you mention "..the push/pull of the ram is balanced by the opposite forces of stock going thru hole in plate.", it's quite the elegant solution. And the extending of the rudder seems to be quite forward as well.

The only show stopper at this point is that the ole girl is sitting in a marina so I can't realistically drop the rudder to remove the quadrant at this time.

But this solution is where I would like to end up eventually.

In the meantime, I'm going to explore the wheel solution as this can be done while she's slipped up. It could very well be that I end up with a backup AP system at least on the actuator end of things, should I end up implementing both.

WTG Len, thank you! I have what I consider to be a solid plan for this option going forward.

[deblen]

Originally Posted by knowclew

Winner, winner chicken dinner!!

When I'm ready to go the linear actuator route, this is most certainly, the way to go.

To be honest, I didn't notice the genius of what was going on, in your post 8 pics, but now that you mention "..the push/pull of the ram is balanced by the opposite forces of stock going thru hole in plate.", it's quite the elegant solution. And the extending of the rudder seems to be quite forward as well.

The only show stopper at this point is that the ole girl is sitting in a marina so I can't realistically drop the rudder to remove the quadrant at this time.

But this solution is where I would like to end up eventually.

In the meantime, I'm going to explore the wheel solution as this can be done while she's slipped up. It could very well be that I end up with a backup AP system at least on the actuator end of things, should I end up implementing both.

WTG Len, thank you! I have what I consider to be a solid plan for this option going forward.

Yea. Mounting the ram on a plate,with a hole in the plate for the rudder stock,is a simple way to remove push-pull stresses from the rudder stock and from the ram to hull fastening. Glad I helped.


I learned what is stronger /better from my install/servicing experience on the local commercial fishing fleet.
If it will stand the daily abuse of a barn door rudder, power steered up to 55 deg. ,3 turns HO-to HO , hundreds of times per day ,on a several hundred HP lobster boat-a pleasure boat is not likely to cause it much grief.
https://www.sbmar.com/articles/marin...ering-systems/


Cheers/Len

[FlyingScot]

Any room for a Jefa DD1 or Navionics rebranded DD15? Very compact. Works great on our 40 foot cat.

[jsanton]

I have a 03 hunter 356. Hunter redesigned it to create the Hunter 36 for a few reasons. One being they couldn’t figure out how to put a below deck autopilot on her.
I did.
Some pictures
Raymarine T1 and follow the directions.