Building the Ritchie Telescope
This page contains an historical journey through the stages of telescope installation and reconstruction. The Ritchie Telescope is a Newtonian reflector with a 27.5 inch zerodur mirror.
The telescope was inside the large observatory presentation room when these first two pictures were taken. The telescope control software and the drive hardware were being tested prior to the scope being placed inside the dome.
The telescope was placed in the dome on December 11, 1997! The crane in place to begin hoisting:
Click here for a "slide show" of the telescope base being hoisted up into the dome (145k animated gif).
Or here for a "slide show" of the telescope truss and mirror being hoisted up into the dome (126k animated gif).
Once the telescope was placed in the dome, an observing platform was constructed (shown in the image at lower left). The edge of the telescope is visible to the right. The computer screen is covered with a rag at lower right.
The right photo is a closeup of the altitude gear and motor. We've decided that this gear is undersized which is leading to some vibration. This gear and stepping motor have given us the greatest amount of trouble of anything related to the telescope.
The next two photos are of work on the telescope gears (photos by Robert von Bereghy), showing John Rudolph, Dave King, and Dan Caster.
The telescope was able to be used visually at a number of public events in 1998 and early 1999. The lower left picture is of taking the dust cover off the main mirror (photo courtesy of the Seattle Times) and the telescope in operation (photo by Robert von Bereghy) with Paul Below and Polly von Bereghy.
In mid-1999 we began the second round of construction. This involved rebuilding the rotating ring to improve stability and shortening the trusses to allow the use of the CCD camera. While we were at it, we rewired the telescope to run all the cables inside to be out of the way. A new desk was constructed, finderscopes were mounted, and other miscellaneous improvements were undertaken.
The next two images show the secondary mirror and ring at the top of the scope near the top of the dome. The ring rotates, allowing the eyepiece to be moved into the best postion for viewing. The dome hatch motor is visible at the top.
The left image shows the ring prior to the 1999 rebuild, the right image is the year 2000 result. The truss tubes were shortened to allow digital imaging. The focuser was installed inside a sliding plate to allow easy installation of the CCD camera. The rotation of the ring was motorized. In the "before" picture, a small counterweight is taped to the top of the secondary ring. An Orion EZ finder is visible at right center in both images, it was mounted to allow us to easily locate the alignment stars at the start of a viewing run. The new connection box for all the controls and power is visible in the "after" image, directly under the ring.
The next picture is the dome interior as it appeared in early 2000, following the second major round of construction. The observing platform is on the left, the new custom-built desk is in the foreground. A new 90mm refractor that holds the Vidicon video camera is mounted in the center. The wires for the rotating ring drive await permanent installation. This picture is a mosaic by Rik Shafer.
The final image on this page shows the Vidicon (low light level video camera) mounted on a 90mm rich field refractor. The refractor can serve as a remote finderscope, and the video cable is connected to internal wiring allowing images to be shown in the meeting room on the ground floor. A couple of other items visible include the new counterweights (shiny lead plates bolted to the bottom of the main telescope) and the break that was installed on the altitude gear (friction clamp that holds the gear in place to allow for maintenance work to be done without damage to the gear or drive motor).
All photos by Paul Below, unless otherwise noted.