Dome Replacement Project – 2025

January – Membership votes to move forward with replacement of the existing dome at Hidden Valley Observatory.

    Ash Dome in Plainfield, IL, is selected as the manufacturer.

Rick at Ash Dome. Trailer loaded for the return trip to Hidden Valley Observatory

  
 
June – The new dome is ready for pickup! Rick, Observatory Director, and Kip, Deputy Observatory Director, pull a trailer to Plainfield, IL, to transport the completed dome from Ash Dome manufacturing to Rapid City.

The dome is packed as a kit for assembly upon arrival at the observatory.

Before departing, Rick and Kip tour the manufacturing facility to see step-by-step how custom domes are created.

 
 
 

    June 24 – The new dome has arrived!
    Kip and Rick, our weary transport team, arrive home safe.

Hidden Valley Observatory

    June 29 – Prepping for assembly

Rod and Rick reviewing the pieces for assembly

Unpacking the smaller bits and pieces

The instruction manual for assembly – with pictures!


    June 30 – Assembly begins!
    The pieces of the dome support ring are fit together. With round shape and level assured, the rollers and skirt were added with no issues.

The ring of the dome base comes together

The skirt

A good days work! Pictured: Kip, Jim, Rick, Rod, Richard, Hank


    Shell pieces of the dome are slid into place. The upper rolling and lower hinged doors are added and checked for secure closure.

Rick guides for Richard and Hank

Don and Rick testing the doors.

Doors close snuggly.

A last night with the original dome.

 

    Steel workers are brought in to swap out the domes. An extension is welded to the to the original support ring to raise the height of the dome.
    By raising the height of the dome, the lower, hinged door will clear the wall of the upper roof when the door is open for observing.

Lifting the original dome away

Extension added to ring base for height

The new dome lifting into place
 
 

    1. A significant upgrade is the motorization of the dome.

The doors of the original dome had become very difficult to open. Perched on top of a ladder, wiggling and shoving would slowly move the doors open or closed. Additionally, a careless finger could be pinched when spinning the dome.

Power to the dome!

    With the dome height raised, the pier that the observatory telescope sits on also needed to be raised by adding an extension.
    The observatory telescope is a 12″ Meade LX200 Schmidt-Cassegrain on an iOptron CEM120 equatorial mount.

A higher dome opening

Measuring for 33″ pier extension

Mike, Rod, and Rick installing the telescope
 

    1. This is the second dome for Hidden Valley Observatory.

Nearly all of the work to build the observatory was completed by club members. To help decide the best design for the dome, several scale models were constructed from cardboard by member Ivan Crown. Member Ed McBride negotiated with Rapid Tank, Inc. for fabrication, transport, and crane installation.

Pictured here, members Clark Johnson and Ed McBride assist employees of Rapid Tank, Inc with Byron Painter on the ground, to maneuver the dome into position. Members Bill Lehmann and Ron Dyvig are standing on ladders inside the observatory. The dome is coated with a red primer.

Member Ron Divig wrote an article about the new observatory and its dome that appeared in the February, 1967 issue of Sky and Telescope magazine.

HVO Dome No. 1

Then and Now – A few finishing touches and the new dome will be ready for the next many decades to come.

    July, 1965

    July, 2025

 

 

Origin story – History of the Hidden Valley Observatory, and the club members that built and have run the observatory over the years, can be found on the History page. In addition to written histories are photos, newsletters, newspaper articles, magazine articles, and miscellaneous documents.

 

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