Autopilot for Hunter 356

[Jerry Clark H356 SV Persi]

Chuck: You are right about the amont of room for the cross arm. I had a loose connection with the steering quadrant and removed the cover behind the helm and the space is very limited in there as shown in your photo where you removed the emergency tiller cover. I tightened it up and used locktight and haven't had anymore problems. I will be back on my boat in about 5 weeks and the first decent weather day, I'm going to take the top off my box and photograph my drive mount.

 

[seadaddler]

OK I see the difference with the rudder stock but I saw a photo of a early 2006 36 rudder
post that was not the solid post like my 36 and it was hollow like early Hunters and it had a plate that went on top of the rudder steering arm that was drilled and tapped mounted.
What has me puzzled is Jerry's photo is showing a box low in the cockpit where the linear drive up against the back bulkhead and the documents I had gotten from Hunter has the linear drive at the very top of the bulkhead.
Nick

 

[Neil Spooner]

Hi,
I have offered up the Linear Drive to the under-floor area of the 356 and it looks a good option. A recess will have to be created for the LD as it is too tight without. but this should not be a problem as there is plenty of room under the "bottom" floor for a recess. The LD link would be welded to the side of the drag link from the helm to the rudder arm. A mounting would need to be 'glassed onto the floor for the LD mounting.

This is a view of the under-floor area showing the rudder tube from the floor, and the raised floor to be fitted with the recess just to the left.

I don't think that the water/weather should get to the LD very much to a be a consideration.

Regards,

Neil

 

[Ken Archer]

Hi everyone
Thanks for all the feedback. I certainly look forward to seeing Jerry's photos when he can get them.
I have been trying to collate all the information I have gathered on this issue, including your posts, and have put together a summary of where I am at. I certainly haven't fully resolved how to install the LD, but at least think I have identified the main problems and issues which need to be considered. I attach what I have come up with. It is a bit long and wordy, and some of the things are a bit difficult to describe succinctly, but I hope you can get the gist of what I am trying to describe. I welcome any feedback, especially where I have made some obvious errors!
Cheers
Ken

 

[Dan_Y]

Our 36 has a raymarine s1 wheel pilot from 2008. Works great inshore when pointing and reaching as long as sails are trimmed and balanced. Steers a course better than I can. But on a broad reach in decent sized following seas the AP struggles and can have 20 deg deviations in heading. The fix, which is no longer available from raymarine, is to add a yaw gyro. If you are handy, you can build one for about $100 or less and from what I have read, makes a great improvement. Building and installing the yaw gyro is my spring project.

 

[Al Miller]

I have done the modification on my 04 H36 which is one of the very first ones after the H356. The key is to replace the tiller arm with either the double arm one made by Edison or get the new double arm from Lewmar that was made for the 05 and newer h36s. The 356 and the 04 h36s used a larger diameter rudder shaft that the arm was pined to. The newer h36s use a smaller rudder shaft and it is keyed. I purchased the Lewmar unit (drawing attached) and had a shop bore it for the larger diameter shaft. Then they bored the hole for the pin to get the same angles as the old arm for the arm which the draglink attaches to. If anyone is interested I will post pictures of the modification. The AP has over 15000 miles on it now as we cruise full time.

 

[Ken Archer]

Hi Al
Thanks, this is very useful information. It seems I may have made a false assumption on the length of the tiller arm used as your drawings indicate that the arm joining the AP is 250 mm. I was just going on the photos and it looked as if both arms were the same length. I would also be very interested in any pictures you could post, and any further information on where and how you mounted the linear drive. As previously discussed on the forum, it is uncertain how the 356 and 36 may differ in layout under the cockpit. Nevertheless, I would appreciate any information you can provide on this issue.

 

[dfriha]

I have recently purchased a Hunter 356 and want to install an autopilot. I have been informed that the Hunter 356 is on the borderline recommended displacement weight for a wheel mounted autopilot (such as the Raymarine EV100), and that I should probably fit an inline drive model (Raymarine EV200). Evidently the only option fitted to new 356 models was a wheel mounted autopilot. I have found instructions to mount an inline EV200 model on the Hunter 36 but the under cockpit structure is different to the 356, and I might have to cut into the aft port side locker to fit the inline drive in place. Can anyone advise me, firstly of any experience they have with a wheel mounted autopilot on a 356 (ie has it performed OK especially at sea), and/or if they have fitted an inline model, and how they went about doing so.

This is an option. Look at a CPT autopilot website. It is a simple above deck belt drive.

 

[Ken Archer]

Thanks, I have looked up the CPT website and it looks interesting. Have you had any personal experience with it, especially on a Hunter yacht? Also, this system is very much a stand alone AP, and doesn't interface with GPS, wind instruments etc. I have not had an AP on a boat before so am wondering if this is a major limitation. How much do people just use their system to navigate by compass bearings even if they have interface with other systems? Also, the newer systems on Raymarine etc seem to be capable of adjusting for sea conditions etc. The CPT would certainly resolve a lot of installation issues for a linear drive, but I did see a reference to the CPT being a bit more difficult to install on a Hunter 356/36? I would appreciate any further comments/experiences with the CPT system, especially on a Hunter 356/36.

 

[Stu Jackson]

Here's some earlier discussion about this:

http://forums.sailboatowners.com/in...topilot-for-c30.169964/&highlight=interfacing

CPT are the people to ask about your Hunter. Have you read their website? They have a very detailed section on doing measurements on your boat before you order so they can get the right partas for your particular boat.

I'll betcha that they've done yours in the past and will know, but they still need them to confirm no one has done anything, well, uhm, weird, to your boat! Not you, of course.

The CPT guys are super nice and helpful, among the best in the industry.

Good luck.

 

[Franklin]

Well, if what they say is true, that the CPT has 86 fl/lbs of torgue, then that is much more than my Type 1 Rotary drive which by my calculation is 56 ft/lbs when including the gear sizes. Mine does just fine on my Hunter 376 which is loaded down to about 18,000-19,000 lbs now, even beating into rough 10' seas or taking 10' steep seas on the beam. So if their claim is correct, then power isn't an issue.

It doesn't sound like it has any kind of gyro on it so input into the calculations like healing motion will not be used and that is a big part of the equation for a Hunter. I know because when I had the settings for that wrong she didn't react fast enough to healing motion and would round up a lot on beam reaches in gusty conditions.

My understanding on how the Raymarine system works is you can set the level of response really low to save energy usage but if you have the Heal setting on high, as soon as it heals over it reacts immediately to the gust no matter how the response setting is. I kind of like that.