Personality, Ingenuity, Oregon Star
Party style
2013 Telescope Walkabout, Mel Bartels, images by Barbara Bajec
Ingenuity and personality were on
exhibition at the 2013
Oregon Star Party Telescope Walkabout. The walkabout began Friday
afternoon
under increasingly gray skies. An excellent crowd walked from scope to
scope, hearing the builder discuss the design features, what is working
well and what needs improvement of his telescope. Encroaching thunderstorms scattered the crowd near the end.
Here I am waiting for the crowd to gather while storm clouds build.
First up was Bob Clements from North Carolina who showed an
equatorial table that changes latitude by adjusting a vertical bolt in the back along with a 10 inch [25cm]
scope with
ingenious repurposed parts. Here's the bottom plate and top plate of
his Equatorial Table with Bob discussing the details of the
rim that's driven by the stepper motor.
Here's Bob unpacking the equatorial
table and 10 inch from his RV and positioning the rocker on top of the
table.
Bob found his trusses at Home Depot
by repurposing a folding chair.
And finally, Bob assembling the top end which fits into the mirror box
for transport.
Next up was Chris Tribe with his ultralight 20 inch [51cm] f/4.5 with
an inch thick [2.5cm] quartz mirror by Zambuto. The telescope weighs 69
pounds and is made from carbon fiber over a balsa wood core. The 0.01
inch [0.25mm] wire spider uses guitar tuners though the wire is not
held at high tension. 'GoPro' camera mounts are used for the truss tube
connectors. Chris also brought his 14.5 inch [37cm] which was shown in
a previous walkabout.
Jerry Oltion showed his 2.5 pound foam upper end 12.5 inch [32cm] f/4.5
track ball scope, a ball scope that tracks with a simple roller
mechanism and DC motor. In order to keep the center of gravity reward,
he calculated that he had to keep the entire upper end including
structure, focuser, diagonal, diagonal holder and spider to 2.5 lbs. He
actually achieved better and had to add a couple of ounces of
counterweight. Sitting nearby was his first attempt at a foam upper end
but it proved too bulky for his tastes. His wife Kathy looks on.
Jerry also showed Chuck Lott's CloverBall scope, a design of Tom
Conlin's that ingeniously avoids the ball. Attached to the
rear of the fins is a
length of surgical tubing that stretches when the scope is tilted
downward; its tension is adjustable for different eyepiece weights.
Finally Jerry
shows that the ball need not be perfectly round by using a helmet for
the sphere.
Under threatening skies, Tom Conlin showed his ingenious SudiBall
design holding his 16 inch [41cm]. Here, the ball is replaced by three
curved wood members that intersect twice at at total of six locations
for maximum structural integrity. The wood pieces fit into a rim, in
this case, a cut down barrel from the local recycle center. The
telescope can be aimed easily anywhere in the sky with the eyepiece
rotated to the most convenient observing location. Like others, Tom
finished his scope the night before, getting a grand total of two hours
sleep before heading over to the star party. A smaller version sits
nearby. So finishing touches to come later! More at https://github.com/TomConlin/Sudiball
As lightning flashed closer, Brett Schaerer showed his ingenious 6 inch [15cm] 'WikiKea' travel
scope that he observes with in Hawaii, built quickly (the Wiki part) from parts found at Ikea (the Kea
part). Brit's scope features an upper end that holds the diagonal and
baffle in a circular member with a diameter smaller than that of the
primary mirror. He also uses a simple but effective sliding focus and
sliding balance mechanism.
Finally, just before the raindrops fell, I showed my 10.5 inch [27cm]
f/2.8 plate glass meniscus mirror that I finished two nights before. A
meniscus mirror is slumped from a flat piece of glass to the desired
focal ratio so that the mirror has the same thickness in the middle of
the mirror as the edge of the mirror. I also showed my star test rig that
I used to accomplish the final parabolizing. The star rig stands up on
an arm so that it is aimed at Polaris. A simple sliding mechanism
suffices for the focuser since the high power eyepiece has to be slid
back and forth numerous times to read the mirror's profile.
Personality and ingenuity on display at the 2013 Oregon Star Party!
A nice article on OSP '13 http://darkerview.com/wordpress/?p=10456
The OSP website https://www.oregonstarparty.org/oregonstarparty/default.aspx
eod