Rick,

 

Thanks for the input on autopilots drives. Bill, from Amadon Light, has a
working Alpha drive unit and wants to match it up with new Simrad Robertson
electronics. The problem, as I understand it, is that the rudder feedback
mechanism on the Alpha is totally different than what Simrad uses. When use=
d
together and deactivating the Simrad autopilot the Alpha drive will want to
continue to steer and burn out the motor. The goal is to somehow get rudder
feedback data from the Simrad device to shut off the Alpha drive. At this
time it's doubtful this can be done but I am going to consult with a
knowledgeable marine electronics tech and see if there is any possibility t=
o
make these two components work together.

In the case of the installation on Gray Eagle - the hydraulic linear drive
,installed 6 years ago by a company now out of business, was supposed to be
bolted in and oriented so the mounting foot is located aft (less than 90
degrees) from the tiller arm. Instead of this it was bolted forward of 90
degrees which compound the mistake as it is almost 30 degrees off from
ideal. When the autopilot steers full lock so the tiller arm is on the port
side (drive piston retracted) it aligns the tiller arm with the ram piston.
Now, when the ram piston wants to steer back the other way it is pushing
against itself and any sea state at the time. The force generated is applie=
d
directly to the glassed in half height wall where the ram is mounted. Force=
s
generated over the years of trying to steer this way eventually cracked the
tabs where this wall is glassed to the hull. The fix and reinforcement is
not difficult as we caught it before any very serious damage was done but
the entire ram installation must be re-installed correctly. As I mentioned
in a previous email, the Simrad HLD2000L drive is not powerful enough to
drive a Baba 40 and never should have been specified for this boat.

 

As the project planning for correcting all this moves along quickly I have
ruled out a one shot purchase of all new equipment. Bill mentioned several
bigger boats using the same electronics I have, so the plan now is to chang=
e
all the hydraulic equipment and install this properly. Next spring I will
connect it to the existing AP-22 electronics and test the system. If all
goes well the problem is solved for much less money than the original deale=
r
estimate. I did consider a new W-H Autopilot but Casey and his electronics
tech friend, Andy made a trip over to look at the equipment for me and thei=
r
opinion nixed this idea, (what a great bunch of people on this forum). I
just downloaded information on a Raymarine hydraulic linear drive, (Type 2,
Model 81200) that can handle displacements up to 48,500 lb. and looks as if
it would fit the very restricted space available. I'll let you know how it
all turns out as I'm sure I will change direction on this a few more times
before winter haul out.

 

Rich Cassano

  

-----Original Message----
From: Richard B. Emerson [mailto:pavilion # pinefields.com]
Sent: Tuesday, August 02, 2005 8:42 AM
To: Baba, Panda and Tashiba
Subject: Re: [baba] More BlaBla on Baba Pilots

 

Throwing in my two cents worth, a dock neighbor has an Alpha a/p and the
electronics are, indeed, the pits. His drive failed while in the Caribbean
a few years back (don't recall why) and I had a chance to play with the new
drive. FWIW, it looked darn near bulletproof and the unit since has steere=
d
the boat (also a Perry design, as a matter of fact: Nordic 40 - lighter tha=
n
Gray Eagle).

I'd pass along whatever I can about the one Robertson hybrid installation
I've seen but the boat was sold and the owner has since "swallowed the
anchor" and moved to FL.

The comments about the drive being on an angle leave me thinking "gotta see
pictures to really get this" but on OWTW, our drive, with the rudder
centered, lies squarely athwartships. While I suppose, with the right
mounting, it doesn't matter that much, seeing the unit other than square to
the rudder and the ship would at least raise a flag - "now why is is that
way???" Clearly something is wrong or this thread wouldn't have been
created.

Rick Emerson
S/V One With The Wind, Baba 35
 


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Received on Tue Aug 02 10:04:58 2005