Rotary vs linear drive for autopilot

The IP35 I purchased 3 years ago came with an old autohelm wheelpilot that is way beyond its useful. the new Raymarine wheelpilot is only rated for 16k displacement, and everything I have read indicates that is overly optimistic. I will replace it with a below deck unit.

My 35 still has the between the legs rack and pinion steering. It looks like a rotary unit could be installed in the housing under the helm seat and the steering sprocket attached directly to the rudder post. The 1/2" key-way on the top of the post looks long enough to accept the sprocket key. The chain would be very short, but the rotary drive would be very accessable.

Has anyone installed a rotary drive on the rack and pinion steering like the IP35? Any thoughts would be appreciated.

We added a shelf and used a ram pilot. This is very powerful and it has worked well since 2002. If I were doing it again, I would do the same install. One key aspect is to cut an access hole in the stern to work on your pilot and the cockpit drain hoses. You can see my full detailed installation photos and all other jobs on our ip35 here.

fhayden.com/rockhallfleet/islandspirit/b_&_g_pilot.htm



Hayden

I'm in the process of replacing wheel unit with a a rotary type 1, there is a bracket that goes beneath the rack and pinion and a sprocket to the aft end of the wheel shaft between gears and transom. I have the parts, used , and am working on installation, looks like it should work fine. Check photos I've got it up and running , most excellent. QUIET and powerful.

I have an IP 35 #78?
My autopilot is identical to yours as shown,
except the rudder sensor is mounted just under the teak seat
It's a Type 1 rotary drive , and 7000 autohelm control head.
All replacement parts ie. The motor,replacement control head and computer are all available from Raymarine

It shook a little at first, which I attributed to prop wash on the rudder, and/or a lose lower shoe on the rudder....
It took me a while to get used to it, and adjust the rudder gain properly
Now the more I use it, the better I like it.
Ed

Could you share some info on the suppliers of the sprocket and bracket? Also was it difficult to fit the sprocket on to the shaft. Thanks

Sorry. No. I cant help you there...
The. 7000 series autopilot! Chain drive sprockets and chain drive
Were installed on the boat long before I purchased the boat....

Ed