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Telescopes
I build custom reflector telescopes on alt-az mounts. I enjoy
experimenting with new designs and materials. Contact me to discuss your
goals and pricing. I'd be happy to build a scope tailored to your needs
and preferences. Below are examples of my work.
Medium to large portable "light-buckets"
Small "grab-and-go"
Airline travel scopes
Award-winning,
unique three strut design is lightweight yet rigid, assembles and disassembles
quickly without tools, and collapses into a small package for safe and
convenient transport and storage. 
Enjoy transporting and setting
up a scope whose weight is much less than scopes the same size and often
less than even much smaller scopes.
Why risk damaging your precious
primary mirror by moving it in and out of your mirror box? In the Mark
III, the primary always stays protected in its lightweight mirror
box.
Each telescope is tailored to
your personal specifications.
The Mark III is being made by Custom
Telescopes by Plettstone. Please contact them for availability and
pricing.
Features
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The Mark III
ultralight
design is approximately 1/3rd lighter than most scopes of
equivalent size.
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The heaviest
component is the mirror box which is approximately half the weight of mirror
boxes of scopes of equivalent size. |
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In order to
minimize weight and cool-down time, we use thin custom primary mirrors
1-1/2" thick or less. |
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Each primary
is supported by a lightweight, low profile, floatation
mirror cell. |
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Assembly and
disassembly takes approximately 10-15 minutes. |
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All scopes
are made with
Finnish Birch plywood - the best available.
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Metal components
are made from corrosion-resistant alloys such as aluminum and stainless steel.
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The altitude
bearings can be repositioned along the parallel struts, allowing the
user to rebalance the scope when accessories are later added. |
| If heavier
accessories require additional counterweights, they can be hidden
inside the struts. |
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Mark III - 12.5"
f/5 ultralight
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| The original award-winning
scope. Weighs less than many 10" dobsonian reflectors. Most people
can observe with both feet on the ground.
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Specifications
Primary: light
weight
< 1-1/2" thick primary mirror by Swayze Optical with
standard aluminum coating (90% reflectivity)
Mirror cell:
6-point floatation
Secondary
mirror: 2.14" with enhanced aluminum coating (94-96%)
Secondary holder
and spider by Protostar or Novak
Focuser: 2"
JMI DX2 with 1-1/4" adapter now standard
Truss pole
diameter 1-1/2"
Mirror box
weight: 18-22lbs (depends on thickness of primary)
Upper ring
assembly weight: 4.5lbs
Rocker box
weight: 15-18lbs
Total weight:
50-55lbs
Eyepiece height
at Zenith: 62"
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Mark III - 18" f/4.3 ultralight
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 The
12.5" scaled up to an 18" version very well. The 18" weighs less than many 15"
dobsonian reflectors. The 18" also includes a unique feature. The
three struts have different diameters, so that they nest within
each other for transport.
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Specifications
Primary: light weight 1-1/2" thick primary
mirror by Swayze Optical with standard aluminum coating
Mirror cell:
18-point
Secondary
mirror: 3.1" with enhanced aluminum coating (94-96%)
Secondary holder
and spider by Protostar or Novak
Focuser: 2"
JMI DX2 with 1-1/4" adapter
Truss pole
diameters: one each 2", 1-7/8", and 1-3/4"
Because of the
small f/ ratio, the struts are usually cut to accommodate the additional
in travel of a coma corrector (not included).
Mirror box
weight: 45lbs
Total weight:
92-96lbs
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Components
When building a lightweight
telescope, the primary must be placed as low as possible in order to minimize or
eliminate the need for counterweights. However, the cell must also hold
your mirror securely while maintaining its figure and proper orientation. These
cells have been designed to provide optimal performance for the large, thin
mirrors typically used in portable dobsonian telescopes.
 Six-point floatation cell optimized
to support 12.5" diameter mirrors between 1" to 1-5/8" thick.
Lightweight cast aluminum body with stainless-steel components (mirror support pads, fastening
hardware, leveling bolts, springs, wing nuts, and washers). Mirror is held
securely in place using a thin layer of silicone caulk (not provided)
between each pad and mirror.
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Last updated July 29, 2006
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