Richard Cassano wrote:

> 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 used 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 to make these two
> components work together.
>
Not knowing, past whatever I saw in the BVI (hazed by the consumption of
painkillers...), jack about the Alpha wiring, I can't comment on the
particulars. However, it seems it can be done and that the Roberstson
controller can be coerced into working with all manner of drives.
Sometimes just knowing something has been done or can be done is the
catalyst needed for a project. [grin]

> 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 applied directly to the
> glassed in half height wall where the ram is mounted. Forces 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.
>
Gotit. This is, of course, all very Not Good. I recently treated a
friend to a near vein-bulging rant about marine consultants (the guys
from out of town who charge you to tell you the time of day with your
own watch). Your experience at the hands of Those Who Should Know
Better is another facet of that rant. Cheer up. At least you have the
sense to know something's wrong and know of ways to fix it.

>
>
> 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 change 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 dealer 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
> their 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.
>
FWIW, we have a Type 2 linear drive (electric, not hydraulic). As I
mentioned earlier, there was a problem with the brushes but otherwise
it's worked well. The idea of the hydraulic drive was kicked around but
in our case I think we made the right call. At any rate, we're pleased
with the results. The rudder position sensor strikes me as a little
flimsy and you should include some time/money to see it's well protected
from flying stuff that could be in the area (e.g., fenders,
fenderboards). We also found the fluxgate took a few tries to get it in
the right place. We started near (too close, it turned out) to the
galley and wound up in a locker outboard, to port, of the mast.

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


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Received on Tue Aug 02 12:14:58 2005