Autopilot drive mounting question - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 
  #1  
Old 06-18-2009
Junior Member
 
Join Date: Jul 2000
Posts: 8
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
jvisser is on a distinguished road
Autopilot drive mounting question

(I'm cross posting this from another site; I'm the author; trying ot get more input).

The orthodoxy of below-decks autopilots is that the linear drive be connected to a separate tiller arm that is attached to the rudder post, and not to the existing radial drive.

For those of you not familiar with this setup, I am referring to boat that have vertical rudder posts that are steered with Edson wheel steering, using a circular, cable-driven fixture called a radial drive - like a quadrant that simply goes all 360 degrees.

Edson's recommended bronze tiller arm is a whopping $417! That's the direct price, and for the C-36 unit with 2.860" bore for rudder post, there is no machining charge.

Edson warns against attaching to the radial drive, but gives no compelling reason.

"In no case should the autopilot be attached directly to the quadrant or radial drive wheel!"

I think it's just because they want to sell tiller arms! One purported reason for the tiller arm is that in the event of a steering system failure, the autopilot provides a backup. But, with the linear drive on the radial drive, which is directly connected to the rudder post, there seems to be nothing in the path to break except the radial drive itself, which seems quite robust.

I can only imagine that the radial drive is strong enough to be driven by the linear drive, especially since Edson puts a rudder stop right on the top outside edge of the drive, which can presumably absorb the rudder force in that condition.

As a matter of fact, that rudder stop might be a good place to attach the linear drive, and then make an alternate rudder stop solution.

So, my question is, what are your thoughts on just connecting to the radial drive, and skipping the separate tiller arm?

Thanks,

jv
Reply With Quote Share with Facebook
  #2  
Old 06-18-2009
DwayneSpeer's Avatar
Old Fart
 
Join Date: Oct 2003
Location: Pasco, WA, USA
Posts: 514
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 11
DwayneSpeer is on a distinguished road
It should work but it also puts the drive as the critical piece in the system overall. If you do it you should be sure to inspect it carefully first and if you drill a hole in it that may weaken it.

I had a separate tiller arm fabricated at a local shop for my autopilot and as I recall it wasn't too expensive. You might consider that first.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


Hey, can one of you guys pass me a crab?


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #3  
Old 06-18-2009
Senior Member
 
Join Date: Apr 2008
Posts: 476
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 7
negrini is on a distinguished road
Send a message via AIM to negrini Send a message via Yahoo to negrini Send a message via Skype™ to negrini
Same here, I built a separated tiler below designed to support involved forces. When you push your quadrant using an autopilot, the tremendous force is, mostly times, aplied to where it was not designed to. In special at a distance from the rudder post where the force-arm is shorter, pushing it even harder. I had this arrangement before, and faced a problem just once, when the attachment post on quadrant got loose, enlargening the original hole I did.
__________________
Nave Rara
Beneteau Oceanis 43
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #4  
Old 06-19-2009
Junior Member
 
Join Date: Jul 2000
Posts: 8
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
jvisser is on a distinguished road
Tiller arm?

Do replies count in "post count" so I'll be eligible to send pm's?
Reply With Quote Share with Facebook
  #5  
Old 06-19-2009
Junior Member
 
Join Date: Jul 2000
Posts: 8
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
jvisser is on a distinguished road
Quote:
Originally Posted by jvisser View Post
Do replies count in "post count" so I'll be eligible to send pm's?
Answer = yes.
Reply With Quote Share with Facebook
  #6  
Old 06-19-2009
Junior Member
 
Join Date: Jul 2000
Posts: 8
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
jvisser is on a distinguished road
...and this should be "5," so I can use private messages. Silly.
Reply With Quote Share with Facebook
  #7  
Old 06-19-2009
DwayneSpeer's Avatar
Old Fart
 
Join Date: Oct 2003
Location: Pasco, WA, USA
Posts: 514
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 11
DwayneSpeer is on a distinguished road
Quote:
Originally Posted by jvisser View Post
...and this should be "5," so I can use private messages. Silly.
Sneaky, very sneaky. Anyhow, if you'd like I'd be glad to send you a pic of the tiller arm I had fabed but It'll take a few days as I'm a few miles from my boat.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


Hey, can one of you guys pass me a crab?


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #8  
Old 06-19-2009
Junior Member
 
Join Date: Jul 2000
Posts: 8
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
jvisser is on a distinguished road
Quote:
Originally Posted by DwayneSpeer View Post
Sneaky, very sneaky. Anyhow, if you'd like I'd be glad to send you a pic of the tiller arm I had fabed but It'll take a few days as I'm a few miles from my boat.
That would be great, thanks.

jv
Reply With Quote Share with Facebook
  #9  
Old 06-22-2009
Senior Member
 
Join Date: Oct 2007
Location: Beacon Falls CT USA
Posts: 310
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 7
Pub911 is on a distinguished road
I had the same reaction to the 'single tiller is forbidden' language in the Simrad manual, reiterated by the Simrad tech I spoke to (frequently). I ended up putting a 2nd tiller arm in, but I did it without the hassle of dropping the runner. In my case, the key-way (for the original quadrant connection point to the rudder post) was cut with about 1.5" exposed just beneith the quadrant's fix point. This allowed me to install a Buck-Algonquin 2-part tiller arm - also keyed.

If your concern is the hassle/effort required in dropping your rudder (vs. just the expense of a 2nd tiller arm), carefully examine your rudder stock just below where your quadrant/tiller is attached. You may be pleasantly surprised by an exposed, usable, key-way.
Reply With Quote Share with Facebook
  #10  
Old 06-23-2009
Junior Member
 
Join Date: Jul 2000
Posts: 8
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
jvisser is on a distinguished road
Quote:
Originally Posted by Pub911 View Post
I had the same reaction to the 'single tiller is forbidden' language in the Simrad manual, reiterated by the Simrad tech I spoke to (frequently). I ended up putting a 2nd tiller arm in, but I did it without the hassle of dropping the runner. In my case, the key-way (for the original quadrant connection point to the rudder post) was cut with about 1.5" exposed just beneith the quadrant's fix point. This allowed me to install a Buck-Algonquin 2-part tiller arm - also keyed.

If your concern is the hassle/effort required in dropping your rudder (vs. just the expense of a 2nd tiller arm), carefully examine your rudder stock just below where your quadrant/tiller is attached. You may be pleasantly surprised by an exposed, usable, key-way.
Thanks for the reply. I would not have to drop the rudder in any case: the recommended Edson tiller arm opens on the big end so it can be installed with the rudder shaft in place. And, the rudder post is a stainless steel tube (it's a Catalina 36), so, no keyway. The radial drive wheel is clamped on, then "pinned" via a through hole and nut and bolt. Edson requires that the tiller arm be pinned as well.
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Keel/ballast Question?? Plus Extra Credit Question ;) stephenronning General Discussion (sailing related) 2 03-20-2009 07:25 AM
Robertson AutoPilot (AP 100 DL) Linear Drive (LD100) CurtisWood Irwin 1 08-29-2008 08:46 PM
Question about mounting a cheek block on a mast or boom jaschrumpf Gear & Maintenance 11 05-11-2008 07:08 PM
Cabin top winch mounting boards larsfis Gear & Maintenance 1 03-03-2003 05:10 PM
Hydraulic Drive davidk Gear & Maintenance 1 02-27-2002 12:15 PM


All times are GMT -4. The time now is 06:51 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.