[SAS-BOD] telescopes via the local library

From: Nick Monkman <nmonkman@xxxxxxxxx>
To: sasbod@xxxxxxxxxxxxx
Date: Sun, 8 Mar 2015 23:30:00 -0700
As Debbie mentioned at today's board meeting, there is an interesting
article in the October 2014 issue of Sky and Telescope (p 66, "Check Out
This Telescope")

(if you don't want to read the wall of text below, check out the NHAS
website for more info: http://www.nhastro.com/ltp.php )

Here's a few excerpts, hopefully well within fair use :)

The Perfect Library Loaner Telescope

What instrument best fulfills the requirements of being highly portable,
simple to use, and relatively inexpensive — while providing steady, clear
views of the objects that novices want
to observe? Stowbridge and other NHAS members, resisting the temptation of
aperture creep, decided on Orion’s 4.5-inch StarBlast reflector. It
provides plenty of aperture in a compact, portable, easy-to-use package.

Then the library-telescope team opted to replace the two modest eyepieces
supplied with each StarBlast in favor of
a single 8-to-24-mm zoom eyepiece. It provides good eye relief and a
relatively wide true field, making it easier for the uninitiated observer
to locate bright sky objects.

This combination provides a 21⁄2°-wide view at low power (19×). That’s
enough to fit all of the Pleiades stars, the Double Cluster, and the Orion
Nebula in one wide field, each giving impressive scenes for excited eyes.
At 56×, the eyepiece’s other extreme, users can pick out lunar craters and
mountains, see hints of Jupiter’s cloud features, resolve Saturn’s rings,
and glimpse Venus’s crescent.

Making the Scope Library-Ready

Any off-the-shelf telescope, even the rugged little StarBlast, needs a few
modifications to withstand the rigors of unsupervised home visits — and to
make it as trouble-free and easy to use as possible.

Over time the NHAS library-telescope team has developed tried-and-true
upgrades that have worked well. Every few months the club holds a
“scope-modification party,” at which an assembly line of up to a dozen
volunteers (now led by Pete Smith) turns new StarBlasts into library-ready
units. Here’s a recap of the most important changes they make:

• Eyepiece focuser: The zoom eyepiece can easily be dropped, lost, or
mishandled. So it’s secured in the focuser tube with button-headed
setscrews that can’t be easily removed.
• Collimation knobs: A novice user might be tempted to fiddle with the six
shiny mirror-collimation knobs at the rear of the optical tube. So club
members remove the knobs and replace them with three locknuts on short,
spring-loaded screws.

• Dust caps: The plastic dust caps that cover the main optical tube and the
eyepiece can, and likely will, be lost in no time. So “Can’t Lose Strings”
are added to attach these caps to the scope. • Red-dot finder: The
StarBlast sports a 1× red-dot finder. When aligned with the main tube, it’s
quite sufficient for putting tar- get objects in the eyepiece view. But the
factory-supplied button battery dies in a few days if the unit is left on.
A much more durable solution is to replace it with an external plastic case
 holding two AA batteries. Another solution is to replace the red-dot
pointer with a notched alignment sight.

• Aperture reduction: The Moon is a popular nighttime target, but the
intensity of its light during gibbous and full phases needs to be reduced
for comfortable viewing. Many observers screw a neutral-density “Moon
filter” into the eyepiece barrel, but that could be easily lost. A solu-
tion that avoids the filter altogether is cutting a 2-inch- wide hole in
the optical tube’s end cap to block most of the moonlight entering the
telescope. The hole is covered with a small plastic cap, again anchored
with a string.

After making these changes, volunteers apply laminated, self-adhesive
labels to the main tube and mount. These labels provide a handy Moon map,
magnification and field-of-view charts, and a safety warning to discour-
age pointing the telescope toward the Sun. Club members complete the “kit”
by attaching a small pack containing a laminated 4-by-6-inch instruction
manual, National Audubon’s pocket guide to the constellations, and a strap-
on headlamp equipped with red LEDs.

(...)

  Like books that are heavily used by the public, these telescopes have
limited life spans — they won’t last forever. So the NHAS team pairs each
library loaner with a local “foster astronomer” who checks the telescope
periodically for damage, adjusts collimation, and cleans the optics if
needed. Stowbridge reports that none of the NHAS telescopes has been
damaged due to mistreatment and that no problems have been reported —
except for complaints about the weather!

A Great Community Project

Clearly, the NHAS is onto something, and other clubs across the U.S. (and
in other countries) have initiated library-telescope programs of their own.
To make the startup process easier, the website nhastro.com/ltp.php has all
the details you’ll need — including parts lists, detailed modification
instructions, and downloadable labels.

The StarBlast 4.5 telescope normally retails for $200, but the zoom
eyepiece and other accessories bring the total cost to about $325. Aside
from an outright donation by your club, you can raise funds by asking
library patrons, partnering with “Friends of the Library” groups, and
seeking sponsorships from local businesses.
[SAS-BOD] telescopes via the local library

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