Last Updated 8 August 2000
Page 6 of 7
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Routine Maintenance: The Mount
DGM Optics
OA- Series
Dobsonian style mount offer some of the smoothest
tracking and most comfortable viewing possible with a Dobsonian mounted
telescope. The optical tube assembly is set in DGM Optics
Split Yoke
. The
Split Yoke
allows the tube to be balanced and rotated for comfortable viewing
of any portion of the sky.
All bushing, bearing and trunion parts are custom made using Teflon (TFE) and
Ultra-High Molecular Weight Polyethylene (UHMW). These materials feature
excellent friction coefficients with high chemical and temperature resistance. The
wood is a beautiful, high grade, Atlantic Birch triple coated with a clear
polyurethane finish that will last for years. The finish can be cleaned and
polished with any commercial wood preserving products any time you want to
bring back the "new finish" shine.
As for Teflon (TFE) and Ultra-High Molecular Weight Polyethylene (UHMW)
components, they need only to be kept free of abrasive materials, which may
inhibit the Alt-Azimuth motion(s) of the mount. Cleaning these components by
wiping the surfaces with a clean cloth that has been lightly dampened with
acetone or alcohol.
Note:
It is recommended that chemical resistant gloves be
worn when using such solvents. Also, the vertical bushing/bearing assembly
should be periodically treated with machine oil such as WD-40, or similar
products, to inhibit corrosion of the machine screw and double nut locking
assembly.
The OA-Series
mount utilizes a black anti-static Ultra-High Molecular Weight
Polyethylene (UHMW) disc on the large base plate with the small base plate/strut
assembly riding on Teflon (TFE) pads. Periodically the base plates can be
disassembled and cleaned of any debris, and then treated with WD-40 to
increase the smoothness of azimuth motion. The
OA-4.0
mount features,
believe it or not, vinyl LP records as the surface the Teflon pads ride on.
The
OA-4.0
is now offered with a "Teflon strap clutch". This simple,
inexpensive, device is built in to one of the struts and applies controlled friction
to the trunion bearing and prevents the tube assembly from "falling down" when
various eyepieces are used. This device requires no special maintenance.
However, a thin coat of WD-40, or machine oil, can be applied to the assembly
where the components contact, the trunion bearing, and the Teflon strap. When
additional clamping is applied, the smoothness of the altitude motion is
enhanced. Also, the "Teflon strap clutch" is available with any of the OA- Series
telescopes, and can be easily retrofitted to your scope if you need more friction
with the altitude bearing motion. Contact DGM Optics
for more details.
