your telescope tube without drilling holes into it. Custom designed
to fit telescope tubes up to 14" O.D.
Clamshell rings close using thumbscrews fitting though the side of
the top clamshell board and screwing into a 1/4-20 insert in the abutting
board. Loosening the thumbscrew allows movement of the tube forward
or back, or turning it for convenient eyepiece position. Rotating
rings are contained in a clamshell ring and are essentially the same
as the clamshell, but provides very easy smooth rotation of the tube
for convenient/comfortable eyepiece and finder positioning. Rotating
rings do not allow forward or back movement of the tube. Rotating
the tube is advantageous when observing low to the horizon; rotating
the eyepiece upward. When near zenith, turn the tube and position
the focuser toward the side to avoid leaning out over the telescope.
Clamshell Rings Only:
For Equatorial Heads.
will match your mouting hole size and center to center dimensions.
Clamshell Rings With Altitude Bearings:
For Dobsonian Mounts.
with altitude bearings to match dimension between mount side boards.
Requires 1.625" minimum space between tube and side boards..
Clamshell Rings With Internal Rotating Rings:
With And Without Altitude Bearings.
bearings on an equatorial head, or with beairngs on a Dobsonian
mount. Combine a clamshell ring and an internal rotating ring. The
rotating ring spins freely inside the clamshell rings. A nylon screw
through the top front outer ring (see hole in right photo) tightens
against the inner ring to preferred friction, or locks rotation
Additional Ring Sets:
Mount Smaller Tubes In Same Clamshell.
equatorial or Dobsonian mounts. Add additional smaller telescope
tubes in the same set of clamshell rings. Quickly attach/detach
with four socket head bolts. Left photo: one half of additional
ring set removed (shown on ground) and 1/4-20 threaded insert visible
in the larger diameter clamshell ring. Right photo: second set of
smaller inside diameter ring segments installed.
All parts included, wooden parts are rough sanded with 80 grit, holes
predrilled. All parts dry-fitted before shipping. Kits may be shipped
What you'll need: Philips screwdriver, sandpaper, wood glue.
Materials: CNC precision cut 3/4" Baltic
Birch plywood. Anodized heavy duty aluminum piano hinge. Steel wood
screws. Clamshells open and close using a 2-1/4" thumb screw
that passes through one of the top boards into a 1/4-20 brass threaded
insert in the abutting board. Rings are cut 1/8" larger than
tube circumference. 1/16" cork/rubber lining material included.