|
Carbon
Fiber Secondary Mirror Assembly - 24" Dream Astrograph |
|
|
To the right is a portion of the carbon fiber secondary
mirror assembly for the 24"
Dream Astrograph. |
|
The assembly as shown weighs 224 grams. It will hold
the 7.75"
minor axis cellular secondary mirror, which weighs 2.7 lbs. |
|
The assembly is fabricated with the same method and
materials as the rest of the Optical Support Structure: carbon
fiber, high temperature epoxy, vacuum bagging and a specific
cure (oven) cycle. |
This part therefore matches very closely to the CTE
of the mirror that it supports. |
|
|
|
|
|
|
|
The yoke (mirror cell) design allows a great deal
of air to the back of the cellular mirror. This will help this
optic follow ambient temperatures. |
|
A raw stainless steel spider vane can be seen in the
background on the top of the photo to the left. |
|
To the right are the cellular 7.75" and 5.75",
for the 16" and 24" Dream Astrographs. |
|
|
|
To see additional views, click on the rendering to
the right. |
|
|
|
|
|
To the right is the carbon fiber secondary mirror
assembly for the 24"
Dream Astrograph. |
|
The assembly as shown weighs 812.3 grams (1.8 lbs).
It will hold the 7.75"
minor axis cellular secondary mirror, which weighs 2.7 lbs. The
two carbon fiber subcomponents weigh just under 250 grams each.
Together they represent just over 1 pound. |
|
The assembly is fabricated with the same method and
materials as the rest of the Optical Support Structure: carbon
fiber, high temperature epoxy, vacuum bagging and a specific
cure (oven) cycle. |
You can see the two controls that project out of the
left side of the assembly. These are the free (gross) adjustment
of rotation and the micrometer adjustment of rotation, which
are indepedant of tip/tilt and axial adjustment. The micrometer
allows rotation adjustment as fine as 1/60th of a degree or 1
arc minute. |
|
|
|
|
|
|