UPDATES VARIOUS

Thanks to Dave Berkstresser for the response to yesterday's question about
aluminum teflon anodizing... I'll call for literature. Dave wrote:

>Tufram is the name that General Magniplate gives their aluminum coating
>consisting of a hard anodize with teflon pore fill.
>
>General Magniplate California
>2707 Palma Drive
>Ventura Ca 93003
>(805)642-6262
>
>Further, any generic plating shop should be able to give you the
>same thing under the name "Everslide."

In kayak/ama/float news, I received word today that Current Designs is
willing to create two custom kevlar hulls at a materials cost of $300 each.
Drew at Nelson/Marek confirmed that this is a very good deal but did raise
the caution that, "Since we haven't even begun to calculate the stability
needed for the Microship, we don't know the volume needed in each kayak..."
Prior to committing to the hull order (delivery estimated at 3-4 weeks),
therefore, I've put them in touch with each other to discuss this issue.

I do believe we can achieve higher than normal "absolute flotation," since
we can define deck height and will, in any case, have a substantially
raised coaming and deck to accommodate the pedaling envelope. My initial
rough calculation of 1570 pound bouyancy may therefore be on the low side.
The problem here is the transfer function between immersion and bouyancy:
if the hull has to be sunk well below the surface to achieve sufficient
resistance to heeling moment, then the cross sectional shape is all wrong.
What I'm calling "absolute flotation" is nowhere near as important as
achieving adequate bouyancy when fine hull lines are all that's in the
water -- not when we're churning along, dragging akas and deck fittings
through rushing froth. (Disclaimer: This whole paragraph is coming from a
hydrodynamics neophyte, and there are doubtless formal names for these
phenomena that better express what I'm trying to say!)

Incidentally, the specifications of a stock Current Designs Libra double
sea kayak including a standard deck configuration are:

Length: 21'8" (6.6 m)
Beam: 30" (76 cm)
Weight: 84 lbs (38 kg) (or 74 lbs for the kevlar layup)
Depth: 15.5" (39 cm)
Volume: 184.4 g (691 l)
Cockpit: 16x31" (41x79 cm)
Hull design: Fish form, shallow vee soft chine



WATERPROOF POINTING DEVICE

Tonight, I went over to the apartment of Frank Araullo and Dave Yao after
they spent a couple of hours working here at the lab on the Linear (more on
that in a moment).

Before my arrival, they installed the DOS driver software for the Interlink
DuraPoint, the ruggedized pointing device based on force-sensing resistors.
After playing with it for awhile, I've concluded that it's worth pursuing
further: next step is to create a Macintosh ADB interface for it. Such a
thing MAY be available off the shelf -- Frank pointed out that at least one
commercial joystick comes with a patch to make it work on a Mac, though
unfortunately that one ties up a serial port instead of using ADB. In any
case, we should pursue this, since a mouse/trackball replacement that can
be operated while immersed in seawater is not an easy thing to find.

The feel is not as nice as traditional devices, of course, though it's more
sensitive than I expected. The two buttons could stand to be lighter, and
we brainstormed about ways to get a better grip on the .9-inch diameter pad
(concluding that gluing a golfball to it might be a good experiment). But
I think we have found an acceptable solution that will not require any
special packaging effort, which is a big step forward! In use, we will
want BOTH Mac and DOS functionality, with a nearby switch selecting which
machine I'm controlling at the moment.

This is not yet a cancellation of the pointer project based on the same
company's XYZ force-sensing resistor array, though starting with an
established product is a definite time-saver. Now that I've had a chance
to try it, I'll follow up by talking with the vendor about both options.

Again, thanks to Frank and Dave for the help on this.



OTHER ACKNOWLEDGEMENTS AND UPDATES

Anthony Wei is here at the moment doing the Weipoint extraction from my
first Motorola TRAXAR handheld GPS receiver, giving us an entertaining
starter database of real locations for navigation practice. This is the
nature of an information junkie: I collected that data, by golly; no way
am I going to delete it just because I have to return that unit in exchange
for the new model. In case you're wondering, my lab in the engineering
building is at Latitude 032deg 52' 48.67" North, Longitude 117deg 14'
06.42" West. The other 72 waypoints from a drive around the US are in a
Mac text file if you really want to know where my friends live.

Dave Yao and Frank Araullo completed the Linear Recumbent setup and test
this afternoon. We took it out for a ride -- it felt fine, with good
steering geometry and surprising comfort. I've never been a fan of long
floppy chains on long-wheelbase recumbents (preferring the stiffer but more
complex crossover drive), but it seems to stay under control. The decision
now is whether to incorporate this in at least one of the amas. Because of
weight, size, complexity, and likely corrosion issues, I'm tending toward
saying no on this and instead using a small glassed-in pedal/generator
assembly. For land excursions, the Dahon Mariner (a 32-pound folding
bicycle) will be adequate and much less of a spectacle. We'll keep this
recumbent around long enough to be sure, however, so let me know if you
want to try it sometime!

Andrea Woo has volunteered to pick up the HELLO tags for the party/meeting
Nov 6, as well as the scale to help with weight summaries.

Trang Luong has volunteered to pick up the folding tables for the same
event (he has a 4x4, which in my experience is a quick ticket to
popularity! ;-) He has also offered to help with lab clean-up next week
after mid-terms, as have Jeremy Heath and Isaac Chu.

Finally, I did some FTP site maintenance today (ucsd.edu/nomad), dumping
some obsolete files and installing the new Microship overview file
(microship.gen). There's still work to do: updating READMEs, making ASCII
copies of the last four nomadness notes and installing them, and cleaning
up the general organization a bit more. But Fetch on the Mac makes it
quite painless...

Cheers!