Figure 1 shows Dan Watson (left) and Mike Watson hard at work cutting out pieces for the telescope enclosure in the driveway.
This starts a new series of notes which will show progress on the design and development of the Mark IV and other projects. st stands for "Show and Tell". Anyone who has had a small child in the school system knows what this means. Mostly pictures and a few words to show what is going on. Note, that as always, I do not "Own" st notes. Anyone can make one up and is encouraged to do so.
This will show hardware progress, most of which took place in June.
Figure 1 shows Dan Watson (left) and Mike Watson hard at work
cutting out pieces for the telescope enclosure in the driveway.
Figure 2 has Dan and Mike up on the third floor observation deck
putting together the base enclosure.
Figure 3 shows them painting the enclosure sliding roof. You can
see the holes intended for the opal glass screens. The more distant
part of the roof is the light box.
Figure 4 shows Mike (left) and Dan standing proudly by the
finished enclosure. It is shown with the roof in the full open
position.
Figure 5 shows me standing by the compleded enclosure in the
fully closed position. Because of the color scheme we picked, I call
it the "Dead Barney" enclosure. One can picture Barney lying on his
back.
Figure 6 is the telescope mount. It will help a lot in making
sense of this picture to look at
Figure 1 of TN-42.
I have mounted a
135mm f/2 lens in one of the positions, and the Orion telescope in the
other. These are both much smaller than the lens assembly that is
being built in China. The two rods going up and to the right are the
"trombone" focusing slide. The camera is at the bottom right.
Further bottom right is the linear focusing motor. It moves the
camera on the trombone slide in steps of 0.001. The wide separation
of the bearing rods and the rigid construction of the camera back
should keep the CCD at a good right angle to the lens axis as the
focus is moved.
Figure 7 is another view of the mount more from the top. The
declination drive motor can be seen at the center with its wiring
hanging loose. This is a better view of the Orion.
Figure 8 shows the declination chain drive motor between the two
lens cages.
Figure 9 is a close up view of the camera head on its trombone
slide. The shutter motor is sticking out toward the viewer. The
focus drive motor it to the right. The two water cooling tubes and
the desiccant tube can be seen coming off the bottom of the camera
head.
Figure 10 shows the screw and string RA drive. The two brass
blocks move together on a lead screw. A stainless steel wire goes
from the left block, to the right around the wheel section, over the
pulley and through a tension spring to an anchor point. A second
string starts at the right brass block and goes to the left, around
the wheel section, around a pulley, and to the anchor point. The
motor drives the two brass blocks together right and left. The
mechanical design is such that the wires are tangent to the wheel
section. As one wire winds around the wheel section, the other
unwinds. In each block the cold rolled stainless steel thread engages
a full inch of thread. This is intended to average out any thread
variations. I have used this type of rolled thread before on a
plotting table and have found them to be remarkably uniform. The two
brass blocks ride on a 1/4" bearing bar. This design gives a little
so the next version will have two 3/8" bearing shafts with the screw
between. Bert the cat is an interested observer.
