Hi Paul, Thanks for the ideas, lots of good ones! > you wrote > * Edson sells a different radial drive which has a shorter height. Replacing an existing with one of these would be costly but it could free up shaft space for the tiller arm. One needs to check the specs for the shorter radials and see if that option is feasible.
This is one idea Edson engineering suggested to me today actually! Alden got back to me (after speaking with engineering) and has been very helpful. It would be a good deal of work swapping out the radial, and there are some subtle impacts to consider (I can't change the wire track height too much because if it causes steering cable chafe that will require shimming the idlers/sheaves). It also might require extending the rudder stop post. Flipping the existing offset-disc radial upside down doesn't help because it would still consume the same amount of rudder shaft space (nearly all of it, leaving no room for a standard tiller arm). Edson's other idea was to move the existing radial down by 1.75", bringing the concave portion of the disc closer to the rudder stock tube and freeing up enough space for the 1 5/8" tiller arm above the radial. This definitely requires idler/sheave modification though and rudder stop modification. In addition it's a very tight fit to the point where it might not work (1/8" clearance on cockpit floor and aft stern bulkhead). Your 3rd idea is quite interesting, no one has thought of reusing the radial drive hub thrubolts. The hub is contoured and has a ridge, so it would have to be quite a custom part to get a good fit. I've ruled out option B from my original email (Jefa quadrant with integrated tiller arm) because it turns out it too would require idler/sheave adjustments in addition to a custom rudder stop - basically complete steering system redesign. I'm focusing on option A now, which was to have a machine shop make an "offset tiller arm" or "drop" tiller arm. I discovered the term "offset tiller arm" when I found Buck Algonquin makes them (but not in the right size for our boat, and they're bronze castings so they can't do a custom one - they do 1000+ unit production runs). https://www.deepblueyachtsupply.com/89112-89000-series-offset-tiller-arm But having a machine shop make my own offset tiller arm seems doable, as long as I can find a machine shop willing to do it. -Patrick ---------- Forwarded message ---------- > From: Dreuge <[email protected]> > To: [email protected] > Cc: > Bcc: > Date: Tue, 5 Mar 2019 17:24:39 -0500 > Subject: Re: Stus-List Autopilot tiller arm on LF38 *without* bolting > Patrick, > > As you can imagine, I thought about this a bit, and while I choose to use > a radial rudder stop mount for my connections for several reasons. But > there are options one may consider which would utilize a traditional > autopilot tiller arms. Edson makes tiller arms in both Aluminum and > Bronze. To me, it makes no sense to opt for the Aluminum arm as I doubt > it's structurally as strong as using the radial rudder stop mount. A > Bronze arm (or even a custom stainless) is a good choice. > > * Edson sells a different radial drive which has a shorter height. > Replacing an existing with one of these would be costly but it could free > up shaft space for the tiller arm. One needs to check the specs for the > shorter radials and see if that option is feasible. > > * Alternatively, one may consider flipping the existing radial drive > upside down. It would be a challenging to reinstall and adjust the cables, > and who knows, it may actually make the reinstall easier. The rudder stop > can be installed either on top or below on a radial drive, so in principle > that can be mounted back on top, but since the radial plane would be > higher than existing, one may need to go with smaller steering idler > sheaves. While I though about this, I never actually measured for a fit. > > * A third option, and one I thought of after the fact, is to have a tiller > arm custom made so that it bolts onto the radial at the shaft using the > radial shaft bolts. One would need slightly longer bolts, but it would be > very robust. (inspired by the custom bracket mount for my rudder > indicator). > > Finally, with regards to radial/mount failures, I have heard of one where > someone drilled holes in the radial for installing a mounting bracket > rather than using the rudder stop bracket. The set up failed over time due > to dissimilar metal corrosion. I think drilling the radial is a huge > mistake. It makes it weaker and more prone to corrosion. Edson has > reported that over time the radial can corrode at the rudder stop due to > the dissimilar metals. This has been a common cause of rudder stop > failures. While Edson has redesigned the rudder stop, they contend that > failure is due to steering system neglect and lack of system system > inspection. Yes, we should all inspect more. I would like to add that > improper installation likely added to the haste of deterioration. (.i.e. > some Tef-Gel and some DMD electrical insulation paper goes a long way) > > > > > > - > Paul E. > 1981 C&C Landfall 38 > S/V Johanna Rose > Fort Walton Beach, FL > > http://svjohannarose.blogspot.com/ >
_______________________________________________ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
