C.A.L.D.
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It
takes a lot of trial and errors for an amateur astronomer to find or build his
"ideal" telescope. Dobsonian mount made of light wood, azimuth bearing made with 3 roller bearings riding on a polished steel plate, and a center teflon glide bearing for that little friction needed. Tracking planets at high power is much easier this way than with a conventional Teflon - Formica az bearing |
Computer Aided Lightweight Dobsonian
Overview and specifications:
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Pictures taken at early
stages of construction | ||
The Mount
Standard
Dobsonian mount with a few add-ons
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The Optical Tube
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Plywood mirror cell with 3 collimation
counter screws and 3 rubber feet. Still to install: a 12V fan into the 80 mm opening Threaded rods for primary mirror collimation are easily reachable while looking trough the focuser. Collimation is not turning the right bolt in the wrong direction or turning the wrong bolt in the right direction any more ![]() |
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Finder
scope is made from a 50 mm binocular objective,some plumbing parts, screws
and a 20 mm Kellner eyepiece. Materials for the cross hair were found on my sisters hairbrush ![]() |
Focuser is a modified
"Meade" 2" plastic focuser. In its original state its very sloppy and too
tall. I have shortened it for about 20 mm , and fixed the sloppiness by
adding 2 thin teflon strips between the draw tube and focuser
body. |
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A binoviewer comes
to focus without the need of a barlow lens or path corrector. Just loosen
the tube bolts, shorten the OTA for about 100 mm and no problem.Same with
SLR camera |
Full flash
directly into the mirror, the tube obviously needs a anti reflection
treatment... This is the old spider and old finder scope in the
picture... |
Computer
aid
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leveling feet detail |
finderscope "alt-az" mount
detail |
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Homemade eyepieces: Left: 30 mm 6 element 2" 70 deg AFOV Right: 24 mm 2" 7 element 75 deg AFOV |
Homemade 2x Barlow, 19 mm Plossl (45 deg AFOV) and 13 mm 6 element (60 deg AFOV) It is much nicer to look trough them than at them ![]() |
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Comercialy made 15 mm Plossl, 10 mm RKE, and a 10 ![]() |
10x50 binoculars (don't leave home without them ![]() |