[C320-list] Fw: Linear autohelm

[Jeff Hare]

The installation on our C355 is exactly as you describe.  Installed that way, it doesn't have as much turning radius as we got on the 320 with the Type 1 (as you correctly pointed out the typo).  But that's because the bulkhead is closer to the rudder post. So, there are many factors that come into play here.   On the 320 we lost less than about 5 deg of total turn each way and the boat can still be hand steered to turn circles pretty-much in its own length, which we could do before.  So almost no noticeable loss.One benefit of this install aside from a less expensive ram, is that it is compact, strong and you have almost no chance of stuff tangling in the linear drive.  We are always having to be careful of things in that locker on our 355. Of course, ram driven tillers are always throw-limited to much less than 180 deg due to the straight tiller arm and and a decent sized rudder post. The geometry simply doesn't allow for the rudder to be *driven* to the maximim/minimum amount without putting a huge amount of stress on the Ram gears regardless of how you position the ram. It's intended to drive a tiller normally within the middle range of its throw, not the extremes where the torque requirements become very high.We added stop blocks just as an extra degree of safety to not drive the ram close to its limits when hand steering and to protect the rudder pos sensor.Also remember that when you go to the very maximum or minimum throw that the geometry allows, that is very far outside of the range that the autopilot should ever steer when it's navigating.  Manually steering yes when maneuvering, but never with the ram driving the tiller for many reasons.  Ie, what conditions would you ever want the autopilot to run the tiller hard over? In any seastate that would require that, I'm hand steering and most sailors are in the pub. For that reason, we always configure the autopilot controls to limit the amount of turn to the maximum you'd *trust* the system to auto steer, maybe 45 degrees either way or so. But certainly never maximum. Typically you configure it in software to be much less than you'd ever steer manually when manuvering.  Just something to consider.So either install works. 👍 I chose this because it's very compact and strong, and tucked up out of the way. Nothing extra has to be removed to take out the fuel tank or other systems back there.  The 320 has a highly responsive elliptical rudder that seems to take less force to turn than other boats this size I've sailed and this config is pretty effortless in all sea states we have sailed in.But as nearly everyone who has installed the EV linear drive on the 320 would agree, it's awesome.Cheers!Jeff
-------- Original message --------From: Greg Arnold via C320-list <c320-list at lists.catalina320.com> Date: 9/28/24  12:38 PM  (GMT-05:00) To: C320-List at Catalina320.com Cc: Greg Arnold <greg-arnold at gmx.com> Subject: Re: [C320-list] Fw: Linear autohelm I lot of good information below.But when I installed my drive, I just used a setup similar to that onthe bigger boats like the Catalina 380 and 400.  The tiller arm extendsto starboard from the rudder shaft.  The Raymarine linear drive isbolted to the underside of the molded-in seat on the starboard side ofthe bathing platform on the transom.  Fits perfectly, with the lineardrive arm just clearing the horizontal wood platform above the fuel tank.To make this work, you have to use the long version of the RaymarineType 2 drive, as the seat on the bathing platform is too far aft for theshorter Type 1 drive (I believe Jeff's reference below to the Type 2drive is mistaken, pretty certain he used the Type 1 drive).  This meansyou have to pay a premium of about $400 over the standard Type 1 whichonly comes with a shorter arm.Advantages:1.  Due to the longer arm (14" throw rather than 10"), you don't have tolimit the rudder travel.2.  Because the tiller arm extends to the side rather than forward, youdon't have to shorten it to clear the aft cabin bulkhead (I used theJefa tiller arm, which may be very slightly shorter than the Edson unit,and it does come close to the bulkhead when the rudder is all the way tothe right).3.  Because you don't have to shorten the tiller arm, you can mount theend of the linear drive further from the rudder shaft, reducing the loadon the electric motor.4.  The seat on the swim platform is 3/8" solid fiberglass, so strongerthan the non-structural bulkhead on the aft side of the aft cabin.5.  You don't have to fabricate any backing plates, just bolt the driveto the underside of the swim platform with the custom large-headmounting bolts you can buy from Catalina.6.  The Type 2 drive has a bigger electric motor than the Type 1, so itis just loafing on the 320.7.  In heavy seas when the drive is working furiously, you don't have toworry about the strength of the non-structural bulkhead on the aft sideof the aft cabin.8.  A mechanical nincompoop like me can do the entire installation,because there is no fabrication of backing plates or shortening of thetiller arm.9.  Raymarine says you need a bigger electronic control unit with thebigger drive.  That is true if  you are a typical Type 2 customerputting the drive on a big boat.  But not true on the relatively smallC320, which puts only light loads on the control unit.Disadvantages:1.  You lose some of the starboard lazarette for storage, as the driveis down there.Greg Arnold2005 C320 #1054Pacific Corinthian Marina in Channel Islands Harbor, Oxnard CAOn 9/28/2024 3:50 AM, wdoc1--- via C320-list wrote:>   Shipmates- forwarding this email with detailed instructions/photos with permission from Jeff Hare. I installed a linear autohelm using this guidance in 2022, and have been very happy with results.> I spent many hours curled up in the port-side aft compartment measuring, installing the shortened Edson tiller arm, installing backing plates on either side of the bulkhead, adjusting the position of the linear drive to get the "throw" just right and fabricating/installing a mount for the rudder sensor. Once the linear drive and rudder sensor were in place, a local marine electronics guy installed the rest of the system. So far it has worked flawlessly!> Bill>     ----- Forwarded Message ----- From: Jeff Hare<catalina at thehares.com>To:wdoc1 at aol.com  <wdoc1 at aol.com>Sent: Friday, September 27, 2024 at 10:15:33 PM EDTSubject: RE: Fw: [C320-list] Linear autohelm>   Thanks Bill,> Feel free to forward that to the group or the person looking to do this.  Or even take that info, combine it with your experiences and write it up.> You can use any of the pics in the photo albums that help.> I'm not looking for credit or anything, just trying to help out. 👍> Cheers!Jeff> -------- Original message --------From:wdoc1 at aol.com  Date: 9/27/24 4:50 PM (GMT-05:00) To:catalina at thehares.com  Subject: Fw: [C320-list] Linear autohelm>   Jeff-there is a linear autohelm inquiry today in the C320 list.I searched through my old emails and found this incredibly helpful email from you.I used your invaluable guidance to install a linear autohelm on my C320 and have been super-happy.> I thought about forwarding this email back to the group, but thought since you compiled all the information it would be better if it came from you.> Thanks,> Bill McConnellDIVERSION2000 C320 #714>     ----- Forwarded Message ----- From: Jeff Hare<catalina at thehares.com>To:"C320-List at Catalina320.com"  <C320-List at Catalina320.com>Sent: Monday, August 22, 2022 at 08:44:57 PM EDTSubject: Re: [C320-list] Linear autohelm>   Hi John,>> I have quite a lot of information on installing the Raymarine EV-200 system on the C320. I'd be happy to chat with you and answer any questions you might have. I used information from Scott Thompson, Allan Field, and others and refined the process quite a bit.  This installation approach keeps it out of the way, without interfering with access to the aft locker and only minimal reduction in lock to lock steering.>> My photo album with a ton of pictures and measurements here.> https://photos.app.goo.gl/KyYK2v2nJy9eU7idA>> As you can see, the aft wall is sandwiched between an aluminum plate inside the aft locker and with a finished stainless steel plate inside the aft cabin to create a solid mounting point for the base of the Linear Drive unit.> https://photos.app.goo.gl/gBPkaJZq7FEDLV1P7> https://photos.app.goo.gl/gHa8KBLrrcWXVN4s8>> Here is the tiller arm I modified and the set of backing plates I fabricated for Bill Culbertson. The brushed stainless steel plate is on top of the heavy aluminum backing plate, and has the protective plastic on it in this picture.> https://photos.app.goo.gl/HVGNA44qzMPkRFrp6> https://photos.app.goo.gl/Rj8YjT7W1p3JfpXr9>> The standard Edson tiller arm 926-10-610-MKII is a great tiller arm for this application. While it is too long out of Edson factory, the place where the linear drive bolt attaches for this boat allows for the excess tiller length to be removed without compromising the tiller so that it clears the aft cabin bulkhead. The bronze bushing made to fit in the tiller arm gap is a pretty important detail. This protects the drive bolt from being stressed and prevents the channel from being deformed when the nut on that bolt is tightened. I have pictures of a Catalina factory install where they didn't use a bushing so you could see what happened over a 10 yr span. Not critical and unlikely to fail, but not ideal.>> My advice is that if you can afford the EV200 system, you won't be disappointed and it should be quite reliable and perform well in conditions that would challenge you more than you'd like. Like I said earlier, the electric Type 2 linear drive with the ACU200 has proven to be very reliable and a great fit for the C320.>> -Jeff Hare>> -----Original Message-----> From: C320-list<c320-list-bounces at lists.catalina320.com>  On Behalf Of John Meyers> Sent: Saturday, August 20, 2022 5:49 PM> To:C320-List at catalina320.com> Subject: [C320-list] Linear autohelm>> I am thinking about putting in a linear autohelm. Haven't been on a boat with it. Not finding much written about this especially on the 320 unless I am looking in the wrong place.>> Any advice? Go for it? Avoid it? Which brand/model is good?>> Thanks>> John Meyers> Muskegon, MI> WInd Chime> 1997 #406>>