[C320-list] Fw: Linear autohelm

[Greg Arnold]

I lot of good information below.

But when I installed my drive, I just used a setup similar to that on
the bigger boats like the Catalina 380 and 400.  The tiller arm extends
to starboard from the rudder shaft.  The Raymarine linear drive is
bolted to the underside of the molded-in seat on the starboard side of
the bathing platform on the transom.  Fits perfectly, with the linear
drive arm just clearing the horizontal wood platform above the fuel tank.

To make this work, you have to use the long version of the Raymarine
Type 2 drive, as the seat on the bathing platform is too far aft for the
shorter Type 1 drive (I believe Jeff's reference below to the Type 2
drive is mistaken, pretty certain he used the Type 1 drive).  This means
you have to pay a premium of about $400 over the standard Type 1 which
only comes with a shorter arm.

Advantages:
1.  Due to the longer arm (14" throw rather than 10"), you don't have to
limit the rudder travel.
2.  Because the tiller arm extends to the side rather than forward, you
don't have to shorten it to clear the aft cabin bulkhead (I used the
Jefa 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 to
the right).
3.  Because you don't have to shorten the tiller arm, you can mount the
end of the linear drive further from the rudder shaft, reducing the load
on the electric motor.
4.  The seat on the swim platform is 3/8" solid fiberglass, so stronger
than 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 drive
to the underside of the swim platform with the custom large-head
mounting bolts you can buy from Catalina.
6.  The Type 2 drive has a bigger electric motor than the Type 1, so it
is just loafing on the 320.
7.  In heavy seas when the drive is working furiously, you don't have to
worry about the strength of the non-structural bulkhead on the aft side
of 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 the
tiller arm.
9.  Raymarine says you need a bigger electronic control unit with the
bigger drive.  That is true if  you are a typical Type 2 customer
putting the drive on a big boat.  But not true on the relatively small
C320, which puts only light loads on the control unit.

Disadvantages:
1.  You lose some of the starboard lazarette for storage, as the drive
is down there.

Greg Arnold
2005 C320 #1054
Pacific Corinthian Marina in Channel Islands Harbor, Oxnard CA


On 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
>
>