Belowdecks linear drive installation on CD33

[alemon]

Preparing to embark on this project in the near future. Looking at the raymarine linear drive unit. Has anyone done a linear drive install on a 33 that would be willing to share install pictures or advice? Thanks!

[bottomscraper]

You might be interested in this older thread on CD36 drive installations:

http://www.capedory.org/board/viewtopic.php?f=1&t=36046

[alemon]

You might be interested in this older thread on CD36 drive installations:

http://www.capedory.org/board/viewtopic.php?f=1&t=36046

Thanks! Thats helpful. I'm just trying to figure out how to even access my quadrant and rudder shaft. Only access is through a small opening in port locker but there hoses running through it and a battery bank partially blocking it. This will be an undertaking no doubt! Curious as to how others may have accomplished this.

[Paul D.]

Femme came with a 1980's Benmar Cetek rotary below decks autopilot which worked for me a few years then lost the plot completely. After a few years trying to fix it (this issue was the old non-hunting CPU and compass) I went with a new Raymarine EV-200 with rotary drive. Our boats are on the heavy displacement side of their WheelPilot working properly and I figured I could use the original connection to the quadrant.

It was immediately apparent that the Raymarine rotary drive was not designed nor strong enough to drive with the quadrant, only the steering wheel sprocket using the purchase from the steering gear to power the rudder. A Raymarine tech confirmed this. I sent the drive unit back and figured out a way to connect the new display head, compass and CPU to the old Benmar rotary drive. It was a surprisingly simple solution and this hybrid arrangement has worked very well in all conditions.

33's have very limited room for a linear drive. My brother installed a Garmin/Jeffe linear drive autopilot in his CD36 and it works well. I think the only way it would work on a 33 would be similar. Mount the drive unit athwartship to the rudder post. Make a hole in the separating bulkhead between the rudder post and the port cockpit locker, mount the drive motor in the aft section of the port locker and run the ram to a rudder post autopilot tiller arm through the hole. It may not have enough length for the ram as the hull curves up in at cockpit area and lots of other stuff is in there. It may not fit in the lazarette either (which is where my rotary motor is attached by chain to a bronze rack and pinion gear aft of the quadrant). I can't imagine you could get a straight (level) shot to the quadrant, but maybe you could if it was offset.

I'd check to make sure the linear drive would be strong enough for a 16,000lb displacement and focus on the measurements and angles needed for the ram to rudder post fitting. And spend some quality time in the hole with a tape measure and a patient, engineering-minded friend. If you don't think it will fit, you may see if Raymarine has a rotary drive strong enough to go directly to a fitting on the post. Or maybe pick up an old Benmar rotary drive, pull out the circuitry and just wire up the motor and clutch to the new CPU. The challenge here I reckon would be connection to the independent tiller arm on the rudder post again. You would have to line up the chain drive and find a rack and pinion to rudder post casting, and I have never seen another one of those, so mine may have been custom made from one of these

https://edsonmarine.com/products/sailbo ... -steerers/

It also is fixed to a glassed in mounting shelf under the lazarette.

This reply may not be entirely encouraging but good luck!

[alemon]

Femme came with a 1980's Benmar Cetek rotary below decks autopilot which worked for me a few years then lost the plot completely. After a few years trying to fix it (this issue was the old non-hunting CPU and compass) I went with a new Raymarine EV-200 with rotary drive. Our boats are on the heavy displacement side of their WheelPilot working properly and I figured I could use the original connection to the quadrant.

It was immediately apparent that the Raymarine rotary drive was not designed nor strong enough to drive with the quadrant, only the steering wheel sprocket using the purchase from the steering gear to power the rudder. A Raymarine tech confirmed this. I sent the drive unit back and figured out a way to connect the new display head, compass and CPU to the old Benmar rotary drive. It was a surprisingly simple solution and this hybrid arrangement has worked very well in all conditions.

33's have very limited room for a linear drive. My brother installed a Garmin/Jeffe linear drive autopilot in his CD36 and it works well. I think the only way it would work on a 33 would be similar. Mount the drive unit athwartship to the rudder post. Make a hole in the separating bulkhead between the rudder post and the port cockpit locker, mount the drive motor in the aft section of the port locker and run the ram to a rudder post autopilot tiller arm through the hole. It may not have enough length for the ram as the hull curves up in at cockpit area and lots of other stuff is in there. It may not fit in the lazarette either (which is where my rotary motor is attached by chain to a bronze rack and pinion gear aft of the quadrant). I can't imagine you could get a straight (level) shot to the quadrant, but maybe you could if it was offset.

I'd check to make sure the linear drive would be strong enough for a 16,000lb displacement and focus on the measurements and angles needed for the ram to rudder post fitting. And spend some quality time in the hole with a tape measure and a patient, engineering-minded friend. If you don't think it will fit, you may see if Raymarine has a rotary drive strong enough to go directly to a fitting on the post. Or maybe pick up an old Benmar rotary drive, pull out the circuitry and just wire up the motor and clutch to the new CPU. The challenge here I reckon would be connection to the independent tiller arm on the rudder post again. You would have to line up the chain drive and find a rack and pinion to rudder post casting, and I have never seen another one of those, so mine may have been custom made from one of these

https://edsonmarine.com/products/sailbo ... -steerers/

It also is fixed to a glassed in mounting shelf under the lazarette.

This reply may not be entirely encouraging but good luck!

Thanks. This is what i'm thinking. The raymarine type 1 linear drive when mounted extends 30.6 inches from midline of the boat to most lateral point of the base. It is mounted at a 90 degree angle from the plane of tiller arm movement. I think there should be enough room to mount the drive unit in the port cockpit locker with the drive arm extending through an opening in the port locker wall. Looking at buck-algonquin tiller arms. I'll get down to the boat and mock up the geometry to see how it will all fit.

[Frenchy]

Thinking about this, I like the idea of a hydrovane controlled by a tillerpilot when motoring.
The tillerpilot will consume fewer amps than a below deck unit and when sailing, the hydrovane uses none. This
wind vane is free-standing; has no connections to the steering system and can be mounted off center.
It's a relatively simple solution, versatile (it can even steer your boat if the rudder is damaged), but
unfortunately, expensive. The below deck unit will be costly too though, adding in the hours
sorting out the mechanics and the actual work. - Jean


https://hydrovane.com/faqs/

[distand]

I’ve been looking into a Type 1 Linear drive on my CD330 as well. I did reach out to Edson to see if they had any records of their autopilot tiller arm being installed on a CD330 but they could not provide any examples. I have not figured out whether it’s feasible yet. Will post if I find out anything useful

[K Chiswell]

I had a short tiller arm made at a local machine shop for our CD330 to hook up a Cape Horn wind vane (clearly the installation is not complete). It should work fine for a below deck autopilot if you modify the attachment where the blocks are attached.





I am happy to share my drawings.