Author Topic: Raymarine auto pilot linear drive  (Read 1295 times)

Hooligan

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Raymarine auto pilot linear drive
« on: July 17, 2017, 08:19:17 AM »
 Has anyone installed a Raymarine linear drive autopilot?

SVJourney

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Re: Raymarine auto pilot linear drive
« Reply #1 on: July 24, 2017, 10:35:35 AM »
Garner has an excellent write up on installation with pictures on his blog.  http://www.sailingseadragon.com/AutoPilot.htm

Edit by Mod: See http://www.pearson365.com/forum/index.php?topic=1882.0 for Sea Dragon's Autopilot.
« Last Edit: February 25, 2019, 11:29:25 PM by p69Admin »
www.GalleyWenchTales.com is our cruising blog.  Stop in and see our 365 through over 17000 miles of cruising.

Nereid

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Re: Raymarine auto pilot linear drive
« Reply #2 on: February 25, 2019, 11:56:02 AM »
Has anyone Installed this on a 365?
I just ordered a new one and I am having a tiller arm fabricated..
Just looking for some tips because the starboard aft/lazeret bulkhead is pretty hard to reach from the aft side (manageable but tough boat yoga).
S/V Nereid, Hull #193
www.instagram.com/afloataboard/

stbtack1

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Re: Raymarine auto pilot linear drive
« Reply #3 on: February 27, 2019, 09:49:02 PM »
I am in the process of having one installed. If you have not actually having the tiller arm fabricated you may be able to save some money buying one from Edson. It is an off the shelf item. I am following Garners process.

Billy Ellis
Salty Dog 1981  P365 Hull 364

Nereid

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Re: Raymarine auto pilot linear drive
« Reply #4 on: February 28, 2019, 09:19:10 AM »
How do you reach the aft side of the starboard aft bulkhead?
I just bought some marine grade half inch 0.5" that I will tab with the bulkhead and to the hull.
Also I found it to be much much cheaper to have it manufactured.. 70-150$ rather than the 400-600$ for the Edison one.
S/V Nereid, Hull #193
www.instagram.com/afloataboard/

Nereid

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Re: Raymarine auto pilot linear drive
« Reply #5 on: March 07, 2019, 02:39:37 PM »
Has anyone done this on a 365? there is definitely a difference in clearance! between it and the 367
S/V Nereid, Hull #193
www.instagram.com/afloataboard/

Nereid

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Re: Raymarine auto pilot linear drive
« Reply #6 on: March 08, 2019, 10:43:43 AM »
Billy,
How far along are you on this?.. I have all but the drive installed
S/V Nereid, Hull #193
www.instagram.com/afloataboard/

Nereid

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Re: Raymarine auto pilot linear drive
« Reply #7 on: March 18, 2019, 11:09:23 AM »

Ok Billy I got your message, but I couldn't reply for some reason:

Hey I actually just finished it Saturday night!

So there i was looking at the photos of what Garner did and poking my head down there like 'No flippn way!'.
I think there must be at least 6" more clearance under the sole in the 367, than the 365!

I purchased and installed the Type 1 short (displacement of 12" & 650lbf).
Attached to the circular bit of the shaft, with the additional bit of the key made.
I had a tiller arm manufactured for me from a 1" thick piece of aluminum.
The whole set up has less than 1/8" of clearance at the lowest point between the cabin sole (aft under quadrant) and the top of the bolt I chose that connects the two arms (the total clearance between the top of my quadrant and the bottom of the sole is ~2.5").
Also, the tiller arm I had made is not 10", but is in fact ~11" from the center of the shaft to the autopilot connecting pin. I chose to do this because accessing the bolt/pin or attachments through the quadrant just isnt practical when there isnt even enough room to pull the bolt/pin out

The bulkhead attachment that Garner did (aft side of the starboard aft bulkhead) is tooo damn hard to do good glass work in, since you have to be on your back with just barely enough clearance to shimmy your way in (under the cabinsole/propanebox sole). So I glassed/tabbed the forward side of the bulkhead.. and it is strong as hell (I used 4 layers of fine woven cloth staggered).
I was thinking on posting my results and some photos to the thread.

Hopefully that helps?
S/V Nereid, Hull #193
www.instagram.com/afloataboard/

PeteW

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Re: Raymarine auto pilot linear drive
« Reply #8 on: March 18, 2019, 11:42:29 AM »
I bought my tiller arm from  Buck Algonquin. Cast bronze with the keyway cut. About $150

stbtack1

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Re: Raymarine auto pilot linear drive
« Reply #9 on: March 18, 2019, 11:54:03 PM »
Nereid, I am still sorting things out but I think I have the needed clearence using the square part of the post above the quadrant. I would love to see your pictures. Also how did you isolate the aluminum arm from the stainless post?
Billy Ellis
Salty Dog 1981  P365 Hull 364

PeteW

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Re: Raymarine auto pilot linear drive
« Reply #10 on: March 19, 2019, 10:15:00 AM »
There is a bushing below the steering quadrant pushed into the wooden quadrant stop cross beam. I have pictures of it posted if you follow my link from earlier post. Here it is again.

http://www.pearson365.com/forum/index.php?topic=1366.msg7873#msg7873

My quadrant stop beam was rotted so I needed to make a new one. This clam shell design made installation simpler.

http://www.pearson365.com/forum/index.php?topic=1366.msg7519#msg7519

 From a mechanical engineering point of view this bushing is where all the linear forces for a below deck autopilot drive need to be resolved. What I'm saying is the Linear Drive needs to be firmly attached to the quadrant cross beam. Attaching the drive to the bulkhead will introduce flex into the bulkhead and hull. And for the same reason the tiller arm should go below the steering quadrant.

The beam is wood. It can be drilled and metal brackets attached. I would not trust glassing anything to the hull. Its going to delaminate eventually.  Also attaching the tiller arm to the top of the rudder post will introduce an undesirable torsional force on the rudder post.

The way you can determine if your installation is solid is to engage the autopilot so that that the drive is immovable. Then pull on the wheel while you are down below. If there is play in the wheel it will become obvious when the linear drive attachment points flex in relation to the tiller arm attachment point. On my installation since the drive is oriented perpendicular to the rudder, I found I needed to add cross braces (angle aluminum) to keep the aluminum uprights  that Pearson installed, that the quadrant beam is attached, to keep from flexing. These braces goes from the quadrant beam down to the weighs built into the hull at a 45 degree angle.  I would assume that if your linear drive is oriented to be inline with the rudder (forward-aft) this side to side flexing would not occur. 

In hindsight I believe orienting the linear drive forward-aft is the desired orientation from an engineering viewpoint. This would mean accessing the drive through the aft sail locker with the primary attachment point being the wooden quadrant stop beam.
« Last Edit: March 19, 2019, 11:40:08 AM by PeteW »

Nereid

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Re: Raymarine auto pilot linear drive
« Reply #11 on: March 19, 2019, 02:40:58 PM »
I would agree that mounting the arm under the quadrant is a better location to reduce the bending deformation under load. However it would make since for the linear drive to be mounted on the lateral axis (starboard to port) since the resultant torsional force acts 90 degrees and therefore impose a force alighned with the cross beam.
S/V Nereid, Hull #193
www.instagram.com/afloataboard/

Nereid

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Re: Raymarine auto pilot linear drive
« Reply #12 on: March 19, 2019, 02:43:24 PM »
Some photos
S/V Nereid, Hull #193
www.instagram.com/afloataboard/

PeteW

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Re: Raymarine auto pilot linear drive
« Reply #13 on: March 20, 2019, 11:33:54 AM »
Here's something else to consider with your autopilot installation.

Rudder angle from stop to stop on the beam is something you need to measure. Typically it should be +/- 30 to 35 degrees. I'd measure it in your boat to see what it is.

 Also I'm assuming you have a Type 1" linear drive. Pretty sure that model drive has 12" of stroke. Raymarine specifies that the drive needs to hit the hard stops on the beam before the drive hits it internal stops. If not it will strip gears.

That said the linear drive must produce rudder angles that exceed the hard stop rudder angles. Where you drill the hole in the tiller am becomes critical. The math for this assuming 35 degrees of rudder angle from 6" stroke is:

2Pi R 35 /360 degrees = 6". Solving for R in this example means the radius of your tiller arm should be 9.8".

Pretty sure the Edson radial wheel is 10" in diameter. Your tiller arm looks a bit long maybe 12" meaning the best you can do lock to lock is +/- 28.6 degrees. If you have done the math my apologies for butting in.

Nereid

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Re: Raymarine auto pilot linear drive
« Reply #14 on: March 20, 2019, 04:57:23 PM »
Hey Pete,
No worries.. I have done the math and that is close to the angle that I get (and yes the rudder stops were installed after those photos were taken..). The design choice was to make the arm 11" and not the ~10 that they call, so that the pin could be removed without having to drill a hole in the quadrant, not to mention the pin has to be removed from the bottom due to the lack of head space (installing the arm under the quadrant would be a nice design change though).

The downside of having a longer tiller arm means the time per rudder degree change is slower at max drive speed, and the degree change/deflection of the rudder is smaller by about 7 degrees.
The positives are that I can remove the pin with ease for maintenance and the effective maximum torque of the motor imposing on the rudder has increased (by 65 ft lbf). And using the same rating system Raymarine uses for their boats increases the 'rating' of the autopilot to steer a boat that is 26k+ pounds rather than 24k pounds it is originally, which effectively translates as the maximum roughness of the sea that the autopilot can handle.
Therefore 1 extra inch= 1 Ton extra boat weight..
That said if I were to do it again I would mount the tiller arm closer to the cross strut, below the quadrant.
S/V Nereid, Hull #193
www.instagram.com/afloataboard/