From: dwl@watson.ibm.com (David W. Levine)
Newsgroups: rec.boats
Subject: Recursion commissioning
Date: 13 Apr 92 22:49:58 GMT
Reply-To: dwl@watson.ibm.com
Organization: IBM Thomas J. Watson Research Center
Disclaimer: This posting represents the poster's views, not necessarily those of IBM

Saturday:

Well, the yard did their bit and we were greeted by a boat floating in the
water at the work dock, with a mast in it and the rigging in some vague
approximation of the right places. 

We had a good turnout, of six folks for the day, and more than enough
work for all of us. I spent a good chunk of the day working on our
major instrument system install, a fluxgate compass and interface to
the nav computer. This was your typical three part job. Two mechanical
installs, and then some wiring. 

The way Ockam's instruments work is that there's a main computer box, with the
CPU, a collection of display modules and a collection of "interfaces"  The
basic approach is that all the parts are connected b  RU/58 coax, which
supports
a simple time-division LAN. (Yes, a bloody LAN) each possible type of interface
has a an address assigned to it and puts its value on the LAN in turn. The
computer calculates values and puts them on the LAN. Display units are generic
LCD displays which are "programmed" with a little snap in card which tells it
which value to pick up from the LAN. Quite elegent, in many ways.

Adding the fluxgate compass consisted of mounting the compass, the interface
and wiring them together and into the LAN. After some time spent looking and
thinking, we figured out where the parts were going. The compass sensor
wants to be low in the boat, and basically as close to the center of turning
as possible. We discovered that we could mount it in the upper part of a locker
under our navstation. I spent about 1/2 hour convincing myself that this was
possible (measuring, making sure there weren't any large ferous masses
nearby and
then figuring out where the wires could run. 

While I was chasing this, Bill and Jeff got the lacing lines run forward.
(simple cross lacing on the life lines, to make jib takedowns and lashings and 
flakings easier. Sue chased some of the parts that we needed for various
projects. John showed up and got chased to remounted a set of four cabin top
cam-cleats that needed replacement. (We pulled them last week and discovered
that we also needed to replace some of the mounting hardware) 

Jeff got to inspect all the lights on our lifejackets and replace the
batteries (And lubricate all the zippers) He then checked all the harnesses
and finished stowing them. We got the engine going and checked out a number 
of minor problems. In the meantime, we re-installed the nav computer (It got
pulled last week to get it's proms updated) We fired it up and discovered it
wasn't happy. (Four hackers all scowling at a little Z-80 based motherboard)
Dave went off to collect the old proms and some more parts.

We went on and did the second part of the mechanical install, mounting up
a rubbermaid box against a chunk of bulkhead and then mounting up the
velcro inside it to secure the interface within. We then did the wiring,
which was
midling nasty. The fluxgate needed an external 12V line and we wanted it
to hang off
the nav system switch, so we ended up taking a line off the power input to
the instrument system, running it to the terminal block inside the
sealed box and then out to the fluxgate. 

In the meantime, on deck, we got the last of the running rigging setup
correctly, re-installed the loran antenna and did the first bits of static 
tuning for the rig. The nav computer parts showed up and we put it back
together,
discovering along the way that we didn't need the new proms. Well, the old
proms worked fine and we all muttered something about hardware (Mostly being
software people) 

We finished the install and discovered that it all worked on the first time.
A definite credit to Sue, our one hardware type, who's dilligent wiring and
crimping generally works on the first try. 

Our sails then showed up, all in nice sailmaker folds, so we re-packed about
half of them, spent about an hour loading various odd ends and cleaning 
up the boat. 

Sunday:

We finished some more setup, folding sails, measuring the rig and folding
sails. We also did most of the stereo install, (Amazing how time 
consuming wiring is when you are doing it inside a hanging locker)

We offloaded a bunch of work supplies, flaked a few more sails, loaded
the last two crew-members and did something really scary. We went out
sailing!  We got in about three hours of very sloppy practice, discovering
that the rig was still a bit off, the boatspeed in the instrument
systems was very confused and...

We got to set the both of our new spinnakers and practice sets, takedowns
and gybes. Uffh. Sloppy, sloppy stuff. Oh, well, that's why we go out
and practice.  

When we got back on the dock, we found a floating ground on the boatspeed
sensor hookup. Aha! We also lost some calibration numbers in the system
when we muked about with the install, so we re-did those and also
discovered the headstay was still about 1 inch too long, so we took 
that up. 

We'll probably do a boatspeed calibration sometime this week, along with
some more rig checking. Still, it's looking a lot like sailling season.

				- David



David W. Levine      -- IBM Thomas J. Watson Research Center
dwl@watson.ibm.com   -- (914) 784-7427 

My Opinions, IBM's hardware. --