ATM project around a Coulter 17.5" mirror COMPLETE with Intelliscope C.O.L Apogee 6" F8 refractor, CG-5 mount, Coronado P.S.T Criterion 4" F12 Dynascope
Brian Even a broken clock is correct twice a day
-DannyMy warehouseMy Channel
Quote:Can you have to stiff a spring on your collimation bolts? I ask because Iam using valve springs from a leftover engine head's valvetrain in my project. I thought it was a neat idea.
Quote:Quote:Can you have to stiff a spring on your collimation bolts? I ask because Iam using valve springs from a leftover engine head's valvetrain in my project. I thought it was a neat idea. My gut tells me it waaaaay overkill. Valve springs have rates measured in hundreds of lbs; Mirror cells need only rates measured in 10s of lbs.You'll need really strong fingers to collimate.... made even tougher with cold fingers at night.
The Cheapest Astronomer in the World gets excited by Jupiter. Builds dob, builds eq platform, arranges to borrow webcam...
AS of NSW
AS of Hunter Valley
Fact: I like reflectors and big ones. All the refractors I own are either finderscopes, binoculars, or riflescopes.
18"/F4.5 Obsession #1333 fully optioned (OMI Optics)
14"/F4.5 SDM #33 fully optioned (Zambuto Optics)
10"/F5.3 SDM #50 fully optioned (Suchting Optics)
Pentax XW's, T4 & T5 Naglers , UO HD orthos, 6mm Delos, 8mm Radian, 8.5mm Pentax XF, 13mm Ethos. 12mm Celestron Illum Astrometric eyepiece. Rainbow Optics Spectroscopic Eyepiece Set. Orion Optics UK 250 lpi Ronchi grating eyepiece. 2" Astronomiks UHC, OIII & H-Beta filters, 2" DGM Optics NPB filter. 2" Variable Polariser. 2" Hoya colour filters.
Leupold 10x42 & Pentax 16x60 binos.
Jc ATM 10" F6.1, 1/25th wave spec (max wavefront error +/- 1/12.6 in zone 4 of 6, sodium light ), 6" F7 spec, 127mm F9.4 achro Refractor, Criterion DX8, 10 x 50 bin, SP mount/Synscan goto. ETX80 (finder) Canon 20D, PST DSI 1, Butenschön 125mm F13.4 refractor, diy spectroscope and curiosity
Quote:This will be the only amateur scope, I know of, that you will need a torque wrench or rattle gun to collimate Cheers
Quote:Surely, springs from a Nova would be most appropriate...
20 inch f8 Chief Ed Jones designed and a 17 f9 Zanbuto Wide Band Chief Mike Jones designed .Both unobstructed telescopes .
<2 hour drive to gray/black zone “Contrast is not everything. Outside of aperture, contrast is the only thing” -Carl Zambuto
Refractors Reflectors Two Cats A few eyepieces
Quote:A friend has Fiat valve springs on his 13.5" cell. Works well, but stiff to adjust.I'd rather have too strong a spring installed than too weak.J
Celestron 8SE Dobstuff 13.1": Swayze refigured Coulter mirror, 6 pt mirror cell (2 pt edge support) and CF focuser board made by me StarBlast 4.5 ST80/PortaMount II Zhumell 20x80/Oberwerk 15x70 on a Seronik-style tripod boom mount Hubble Optics 18 inch F/4 mirror.
Quote:The cell shifting is the problem. I use push pull screws on the periphery for my cells. I would want at least 10 times the preload on the springs compared to the weight on the spring. springs are just not a positive way to locate a mirror. I have one PP cell that has locating goves for the push of the push pull screw. The unit came from an industrial laser.
Quote:That explains some of the comments I have seen over time that has puzzled me about collimation springs. That is - some cell designs are using the springs to hold the cell in position by gross pressure when the scope is tilted, in addition to their role in holding the cell against the collimation bolt stop.