DFM Engineering was contacted by the University of Oregon to repair
the Right Ascension and Declination secondary drive assemblies for their Boller and Chivens Telescope,
originally built in 1967, located on Pine
Mountain east of Bend, Oregon.
The telescope was tracking beautifully, however, there was excessive gear and other noises when
the telescope was slewed between stars.
We disassembled the drives, checked the bearings and gears, and measured the wear on the R.A. worm.
We found less than 0.0005 inches of wear on the RA worm. We found one small bearing to be
nearing its useful life and replaced it. One of the RA secondary helical gears was also replaced with a
used but unworn gear removed from another B & C 24-inch telescope which we had replaced all of the secondary
gearing on when we retrofitted out control system to that telescope.
The Boller and Chivens telescopes are very well made and require very little maintenance.
However, the electric clutches that are used to switch between the track and the slewing gearing are no
The service life of these clutches may be extended by performing a machining operation on them. Sometimes
the flexible member of the clutch fatigues and breaks. We can fabricate new flex members and service the
clutches. We also have several used clutches in stock along with other secondary drive parts.
Of course, we recommend having us update the Boller and Chivens telescopes with our control system retrofit.
With our Telescope Control System (TCS-Sky) installed, the
already excellent tracking is complemented by the excellent
pointing provided by our computer corrected pointing model and optimized control system.
We shipped the cleaned and refurbished drives back to the observatory within one week of receiving them.
Mr. Mark Dunaway, the Observatory Manager, said he was pleased he could find someone qualified to work
on their telescope.