Assembled scope
After all parts were finished and tested, the telescope was finally assembled.
Two sets of counterweights (lead rings) were needed for the altitude axis. The roll shell rotated about a point near the secondary mirror, so the roll shell needed a counterweight to balance out the weight of the pitch assembly at the front end of the shell. Initially, the aft shell was strictly to support a counterweight that would balance out all the mass attached to the front end of the scope, but it later became quite useful for camera protection and as a mounting point for finder telescopes.
During lab testing the scope was rolled about on a cart to various test locations where it could look out windows, or across rooms, to various targets. On this particular day I had a small finder scope attached and also a hand paddle for motor control.
The pitch mirror and the pitch turn mirror were brought to parallelism using the hall-of-mirrors effect.
A housing for the mercury mirror was prepared using all plastic or rubber components.
The pitch assembly was tested next to the scope electronics.
Here is a detail of the pitch stepper motor drive showing the stepper control chip and the gearing. The stepper drives a worm and worm wheel to rotate the pitch mirror. The pitch mirror (on the underside of the plate) was actually mounted on an extension of the encoder shaft.
Testing the alignment LED. The spherical top of the LED had been sawn off and then polished flat. The LED light was sent out of the scope optics, via a pellicle, as a collimated beam, which hit a retroreflector, and returned through the pellicle to the camera. Note that the square silicon LED die and the die feed wire were visible.
A dew shield was built to protect the electronics from falling parts and dew. It was fun to learn how to work acrylic plastic.
Most of the pieces in place.
Final assembly with annotations.
And installed into the observatory in June 2020. About 14 months, from first paper concept to installation.
