Oregon Star Party Telescope Walkabout, 2023, conducted by Mel Bartels, images by Barbara Bajec
I attended the 1994 RTMC (Riverside Telescope Makers Conference), winning a merit award for my 20.5 inch [52cm] F4.8 computerized telescope. But I was disappointed in the lack of access and amateurs' willingness to discuss their telescopes. I came up with the idea of walking from scope to scope as a group where owners are available to talk about their scopes and answer questions. Steve Johnson from Seattle helped develop the idea. The walkabout is not about winning contents or merit awards, instead it is about learning, sharing, collaborating and celebrating amateurs and their work. We are all capable of being our own judge, evaluating for our own purposes. As Rocky in Hail Mary would say, "Good good good." The Oregon Walkabout began in the 1990s.
We remember three amateurs who are no longer with us.
- Steve Swayze was a bold and creative telescope maker, culminating in his 40 inch [1 meter] F5 first shown 29 years ago at the Oregon Star Party in 1994. We attended the same high school, but did not know of our mutual interest in telescope making until meeting in the dark one night at a star party years later.
- Mark Cowan was working on the holy grail of telescope making, a robotic mirror making machine. He founded Obsidian Optics. A regular attendee, we miss his deep knowledge and precision.
- Albert Highe also attended the Oregon Star Party, writing the seminal book, "Portable Newtonian Telescopes" along with his later "String Telescopes".
I thank Ed Allen for the sound system.
We visited 10 amateurs and their scopes (along with one additional accessory that deserves its own mention). The temperature was searingly hot and quite uncomfortable. I deeply appreciate those who toughed it out. If you find mistakes or desire changes then please contact me.
In the order that we visited (which was dictated by location on the observing field):
- Seth Jeleu, Lake Oswego, Oregon, 17.5 inch F4.5 with interesting use of wood and truss.
- Zane Landers, Tucson, Arizona, 14.7 inch F2.9 fast portable scope.
- Sasha Demenko, Vancouver, Washington, 10 inch F4.5 ballscope.
- Matt Baker, Zionsville, Indiana, 12 inch F4.5 with wire spider and other features.
- Mel Bartels, Sisters, Oregon, 30 inch F2.7 thin meniscus with 3-axis mount.
- Dale Eason, St Paul, Minnesota, SkySolve, a camera based finder, shown by Mel Bartels.
- Howard Banich, Scappoose, Oregon, 30 inch F2.7 with Night Vision.
- (Richard) Miles, Olympia Washington, 16 inch F3.9 string scope.
- John Angle, Granite Falls, Washington, 8 inch F4.5, beautiful wood scope.
- Matt Vartanian, Portland, Oregon, 12 inch F3.9 on an equatorial platform.
- Bob Bjornstedt, Scio, Oregon, 17.5 inch F4.5 binoscope.
Seth Jeleu, Lake Oswego, Oregon, 17.5 inch F4.5 with interesting use of wood and truss.
- no bottom trusses: truncated upper ring and spider
- built from Baltic Birch plywood
- holds collimation well; mirror collimates on a pivot
- truss tubes are 1.5 inch shower curtain rods with Aurora Precision clamps
- Teflon bearings ride against aluminum strips
- altitude bearings have small blocks so the mirror box 'sits' on it allowing them to pop off, and then gently slide mirror box in like Steve Overholt's
- mirror lid folds.
- 90 pounds; fits into Prius.
- Finder finshed just before OSP.
- A Covid project. CAD designed.
- Galaxy mirror resting on a 18 pt back flotation with 2 pt edge support at 120 degrees separation.
Zane Landers, Tucson, Arizona, 14.7 inch F2.9 fast portable scope.
- super wide field of 1.7 deg with 21mm Ethos, a 30mm 2 inch ES is 2 deg field
- 3/4 inch thick quartz mirror with 20 minute cool down
- drum shell upper cage with curved spider
- minimum sized 3.5 inch m.a. diagonal with no P2 coma corrector intrusion
- equatorial platform for tracking (however set for Arizona's 32 deg latitude; trouble here in Oregon)
- aluminum rim bearings
- really compact, 60 lbs
- Heather shroud with Aurora Precision cell
- Steve Dodds mirror
- working on a 30 inch F5
- find him on Discord's observational astronomy here
Sasha Demenko, Vancouver, Washington, 10 inch F4.5 ballscope.
- hexapod ballscope
- wire spider from guitar 'E' string with guitar tuners for tightening
- 3D printed parts from ASA, aluminum tubes, carbon fiber upper end
- twisting truss tubes in pairs to align: upper ones adjust the diagonal alignment, the bottom ones adjust the primary alignment
- Coulter primary sits on 120 degrees separation rollers (ballscope allows tube assembly to rotate)
- the ball is a polycarbonate sphere; heavy eyepieces are OK
- 17 pounds of counterweight behind the mirror to balance, 26 pounds weight overall, scope itself is only 8 pounds
- mount is a bucket filled with rocks and dug into the ground
- planning to add boundary layer fans
- takes one seat in the car
- working on a 26.25 inch mirror along with a 9 inch F2.6 RFT which will also be a hexpod ballscope
Matt Baker, Zionsville, Indiana, 12 inch F4.5 with wire spider and other features.
- Orion primary
- wire spider
- single ring upper end
- truss tubes are shower curtain rods
- working on a 32 inch mirror
Mel Bartels, Sisters, Oregon, 30 inch F2.7 thin meniscus with 3-axis mount.
- 30 inch F2.7 x 5/8 inch thick meniscus plate glass primary mirror that is home silvered; made two mirrors at the same time for very little more effort than a single mirror
- mirror thinness not a problem; primary challenge the 64 waves of parabolic correction
- mirror thermally equilibrates in moments but can suffer if front and back sides are not kept in thermal balance
- 3-axis mounting double flex rocker: alt-az when pointing more horizontal, alt-alt when pointing near vertical
- wire spider and hub are built aligned along with the focuser, there are no collimation adjustments
- 97 pounds overall weight
- no ladder but do need a step stool sometimes; can be used in high winds
- for more, see Mel's webpage.
Dale Eason, St Paul, Minnesota, SkySolve, a camera based finder, shown by Mel Bartels.
- camera based finder uses plate solving software that sends center of image to SkySafari on smartphone
- Raspberry Pi processor, camera and lens
- 3D printed parts
- For more see the May 2023 Sky and Telescope article and the groups.io SkySolve.
Howard Banich, Scappoose, Oregon, 30 inch F2.7 with Night Vision.
- 30 inch F2.7 thin meniscus (twin mirror of Mel's) that is home silvered
- 1.15 deg field of view
- scope originally housed a 28 inch F4 Kennedy Optic; the mirror cell and box reused for the 30 inch; new upper end
- wire spider
- uses Ed Allen's ventilation system
- uses Night Vision device with stunning Hubble like views thanks to the fast silvered mirror
- For more on Howard's scopes, go here.
- for more on the home silvered that Howard helped pioneer, see the January 2020 issue of Sky and Telescope, also go here for the webpage.
(Richard) Miles, Olympia Washington, 16 inch F3.9 string scope.
- Mark Cowan made quartz mirror; blank won at the 2009 Oregon Star Party door prize
- string scope
- 18 pt mirror cell with no collimation bolts (thinking here is that having adjustments just means more adjusting)
- upper end aligned by adjusting lengths of poles by twisting them
- the mirror box is behind a second short box that holds the trusses
- model airplane wood for upper end (marine plywood)
- scope will work with just 2 poles
- 23 pound maximum component weight
John Angle, Granite Falls, Washington, 8 inch F4.5, beautiful wood scope.
- Scope began in 1971 as a Cave scope with mirror made by Tom Cave
- Chuck Dethloff made scope; tube in the style of Steve Swayze; all that remains is the mirror and cell
- tube rotates
- 1.5 deg field of view
Matt Vartanian, Portland, Oregon, 12 inch F3.9 on an equatorial platform.
- Steve Swayze mirrors with Aurora Precision truss tube components
- first scope was run over and the 2nd scope was stolen leaving only the truss tubes behind, hence this scope that uses these truss tubes
- scope painted with a blue stain
- equatorial table finished at the Oregon Star Party
- welded rebar feet: 4, not 3 for more stability and less likely to tip over
- $14 1 rpm DC motor with speed control; drive wheel is from a model radio controlled car
Bob Bjornstedt, Scio, Oregon, 17.5 inch F4.5 binoscope.
- 4 1/2 year project uses 1989 Coulter Optics
- views are inspiring; favorite objects include the Veil Nebula and M42
- T frame aluminum structure sits on a pedestal
- upper flying end slides up and down the main square stack to focus ala a sled focuser
- uses Ed Allen ventilation system (CVS) that's designed to sweep off the mirror's boundary layer, cooling the primaries and sending the warm air spinning upward for the secondary to bask in
- used Eric Royer and Mel Bartels software to design the binoscope
- all adjustments and focusing along with IPD adjustment are motorized and operated through a game controller
- one side of the optics is silvered
- drawback is zenith viewing: somewhat uncomfortable to lean over the scope
- continues tradition of a binoscope on the Walkabout
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