Polarex – Unitron Model 900

This feature discusses the discovery, recovery, and restoration of a one of a kind Polarex-Unitron Model 900 that is located at Delft University of Technology, Delft, Netherlands.  To the best of my knowledge this is the largest refractor manufactured by Nihon Seiko…and the only one of its kind.  It is a 225mm diameter, 3300mm focal length pedestal mounted photo equatorial weighing about 1200 lbs.  All photos courtesy of the owner Alex Boot.  Alex works at UT Delft and is also the owner of 2.4″, 3″, and 4″ Polarex Equatorial refractors.

According to Alex,  “as I can remember, it was 2009. One of my Japanese students helped me set up my 4 inch pier model here outside for a look at a part of a solar eclipse. He told me his father worked at Nihon Seiko and told me there still was some equipment stored there that looked a lot as my 4 inch. I got the phone-number of his father, still working there, but not very willing to take a look in their basement storage. “If I was interested, I had to come to see for myself.”

Nothing to lose, I made the trip but expected nothing. Nevertheless I was kindly invited there to look around. The storage looked very desolated and forgotten, and was “subject to be demolished that same year”. Nobody was sure what really was stored there. On top of a large shelf, covered with a dusty blanket, I found this beauty, with lens apart in a wooden box and clamps in a carton box, all paint was chipped. But underneath I saw the unmistakable Unitron/Polarex quality. I spend 2 weeks there to make wooden boxes out of junk material and stayed at the site-managers home on the same spot. We agreed I should buy what they had and was “helped” to obtain some “easy” shipment documents (“samples without commercial value”)! I flew back with it, to be sure everything was kept together.  Six months after my treasure-finding, this storage area was torn down and all in-house materials scrapped.  Can you imagine this scope on a metal junk-yard?

It stayed here for some years in storage until I found a very suitable place to start repainting, polishing and fitting all parts together. Now it’s getting near the end of it and it’s time to find a good place for “its first light”, possibly Spain.”

The telescope is equipped with a 4 inch guidescope, and two viewfinders, a 60mm x 700mm and an 80mm x 500mm.  “Also included is the Super Unihex, an electrical drive with friction-coupling and hand-controller adjustable for various speeds forward and backward. I also found a 60mm astrograph, not meant for this scope but too nice to leave it there and I will fit it anyway, a “Duetron”, a micrometer-eyepiece, some very different eyepieces such as a wide-angle 32mm, and of course the huge 60mm.”

The telescope is still undergoing restoral and assembly at Delft University of Technology.

Some of the more interesting accessories included an 80mm x 500mm Viewfinder and an electric focuser:

Super Unihex and several eyepieces including the 60mm and a 32mm:

Additional photos will be added as they become available.