Fitting a tiller arm for autopilot in a tight space

[Tessellate]

I'm hoping to install a below-decks autopilot on a C&C Landfall 38, which has very limited space on the rudder stock.

The attached picture shows the space below the Edson radial drive. I have 0.4" straight-edge clearance and 1.9" available rudder shaft (but 1.5" of that is within the concave disk of the Edson radial drive). The Edson tiller arm is 1 5/8" vertical and the Jefa one is 60mm / 2.36" - so neither one fits.

The radial drive has no room to move up, only about 0.25" clearance above with cockpit floor.

Through a lot of research it seems my options are:

A) Custom tiller arm that uses a 90 degree bend, probably stainless steel to increase strength. I haven't been able to find any designs for this except for one picture here: Connecting a new Raymrine linear drive to a steering quadrant - Page 2
(post #13 by knuterikt who I believe is in either Denmark or Norway).
2nd photo attached, and more on his website: Galleri — LP Yacht

B) Removing my near new Edson radial drive (only 3 years old) and replacing with Jefa 270 degree quadrant with integrated tiller arm (~$900). This would be more work and a shame because the Edson drive is in like-new shape and worth $500 (but perhaps I could recover some of that on the used market).
https://www.jefa.com/steering/produc.../quadrants.htm

C) <I've ruled this out>: mounting ram direct to quadrant. Some people have done this but it's not super safe and Edson calls it a "likely catastrophic failure", so I don't want to do this option.

Option A would be easier and cheaper (maybe?), but I don't know of a proven design that is strong enough to handle the linear drive load (Raymarine EV-200). So option B is starting to look better.

Any have any more info (particularly blogs or pictures) of autopilot installs in tight spaces, without attaching it direct to the quadrant?

[RaymondR]

Why is attaching a tiller arm to the quadrant a "recipe for disaster"??

[Tessellate]

Originally Posted by RaymondR

Why is attaching a tiller arm to the quadrant a "recipe for disaster"??

Because Edson says so? It's cast aluminum, and they say it's not designed for point load pushing forces which is what an autopilot does. It's designed for pulling forces (through the cables). A type 1 drive delivers 650 lbs peak thrust and a type 2 can do 1050 lbs.

Many people do so anyway (the fwd rudder stop bolt hole is very enticing!), and most seem to get by fine, but I found one account of someone whose Edson radial exploded (with autopilot arm attached). It took 15 years, but still isn't a risk I'd like to take.

I wish Edson had thought about this in the design (left more room for a tiller arm - their radial drive uses up 3.5" of rudder shaft space), but what's done is done. Mainly I'm curious whether anyone has worked around this some other way, because I find very few reports of anyone using the Jefa integrated tiller arm or a custom tiller arm.

[B-Baysailer]

Buck Algonquin makes a offset tiller arm don't now if that would work for you the 1 1/2 is #89150

[Tessellate]

Originally Posted by B-Baysailer

Buck Algonquin makes a offset tiller arm don't now if that would work for you the 1 1/2 is #89150

I had looked at those, but didn't realize they have more designs than the initial one I found (the kind that isn't a split shaft coupling and requires dropping the rudder). Now I see they do have split shaft ones and the offset one with a descending arm could be just what I need.

Unfortunately they have predrilled shaft sizes and don't go up to 2 3/8" (what I have). And their offset tiller arm doesn't have a split head (requires dropping rudder).

I'm calling them now... No luck - their pieces are all bronze castings, which means they can't make a one-off casting easily. He said it'd be very expensive, they have to make a new mold, do production test runs, etc. He gave me two other companies to check out though - Croix / Marine Associates, and Marine Hardware.

The Buck Algonquin catalog is here FYI in case anyone else wants it (from 2011): https://www.jamestowndistributors.co...log_9_2011.pdf

[B-Baysailer]

Lewmar has some with a split hub and offset to one side might have to cut down the hub some

[Matt Johnson]

Originally Posted by Tessellate

Because Edson says so? It's cast aluminum, and they say it's not designed for point load pushing forces which is what an autopilot does. It's designed for pulling forces (through the cables). A type 1 drive delivers 650 lbs peak thrust and a type 2 can do 1050 lbs.

.

Get out of my head! I had a response written that was verbatim to yours [emoji106].


Personal, with the limited distance you have on the shaft to mount a secondary tiller arm, I'd fudge the "rules" and mount the linear drive to the quadrant. I've worked on a few boats with the same setup and nobody has had an issue... Some with circumnavigations under their belts.


Matt

[Matt Johnson]

By the way... Any machine shop can make you a split tiller out of aluminum for less then the Edson arm. I had two 9" tillers for a 3" shaft made for something like $300 out of 1" aluminum 6061. The first was around $250, but the second was just material cost since setup was already done.

Matt

Edit:. Here is one I had made a few years back for $200 http://www.cruisersforum.com/forums/....php?p=1971216

[RaymondR]

Originally Posted by Tessellate

Because Edson says so? It's cast aluminum, and they say it's not designed for point load pushing forces which is what an autopilot does. It's designed for pulling forces (through the cables). A type 1 drive delivers 650 lbs peak thrust and a type 2 can do 1050 lbs.

Many people do so anyway (the fwd rudder stop bolt hole is very enticing!), and most seem to get by fine, but I found one account of someone whose Edson radial exploded (with autopilot arm attached). It took 15 years, but still isn't a risk I'd like to take.

I wish Edson had thought about this in the design (left more room for a tiller arm - their radial drive uses up 3.5" of rudder shaft space), but what's done is done. Mainly I'm curious whether anyone has worked around this some other way, because I find very few reports of anyone using the Jefa integrated tiller arm or a custom tiller arm.

Sounds a bit nonsensical to me. If you welded the tiller bar onto a piece of 3/8" quadrant shaped plate and fastened it to the quadrant with 1/4" cap screws in say six places it would not only transfer the torque but also reinforce the quadrant.

[SailRedemption]

That Jefa unit would work fine. It's not cast and is made for supporting a ram of some sort.

Also, to second Matt's response, our boat came with a Type 1 or 2 linear drive attached to an Edson full circle quadrant(or whatever the term is for the full round ones) so the PO had success for a long time. We took that out and are going with a hydraulic ram mounted to a custom tiller arm made by our machinist.

Your third option being one made by a welder or machinist. This is what we are doing because no one makes tiller arms that aren't custom for 4" rudder shafts. We also needed a split collar type. Here is a picture of ours in the process of getting made. It's 3" thick aluminum for more grip since we can't/won't thru bolt it. It's clamped together with 4 x 1/2" socket head bolts. It has a 1" plate welded to it for the tiller.

[Jim Cate]

Looks good! But be really sure to goop up those clamping bolts with LOTS of anti-seize when you assemble it. Guess why I make this suggestion...

Jim

[stormalong]

If you are worried about point loading the Edson quadrant why not re-enforce it with some aluminum plate through bolted to spread the load. You could even do two plates, top and bottom.

[SailRedemption]

Originally Posted by Jim Cate

Looks good! But be really sure to goop up those clamping bolts with LOTS of anti-seize when you assemble it. Guess why I make this suggestion...

Jim

Oh, definitely we will! Was going to coat them in loctite so they don't budge and prevent corrosion.

[Jim Cate]

Originally Posted by SailRedemption

Oh, definitely we will! Was going to coat them in loctite so they don't budge and prevent corrosion.

I'd be worried about ever getting them out using loctite with that much bury length, and with so much mass that heating the tiller to release the loctite might be iffy.

But I'm only going on instinct here... perhaps a more knowledgeable person might advise on the matter.

Jim

[stormalong]

Originally Posted by Jim Cate

I'd be worried about ever getting them out using loctite with that much bury length, and with so much mass that heating the tiller to release the loctite might be iffy.

But I'm only going on instinct here... perhaps a more knowledgeable person might advise on the matter.

Jim

Use Loctite blue and only one drop per bolt.