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Everything posted by perrin6
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From the album: 200mm F6 backpack scope
Breaks down to fit in medium-sized bag. Optics; GSO via Bintel, Australia. For use with light eyepieces only eg plossls, orthoscopics, RKEs etc Optimised for high contrast with minimal diagonal size (31mm), guitar string (.23mm) wire spider and v. low profile push-pull focuser made of plastic drainpipe lined with milk bottle plastic. Computer fan mounted on rear powered by 8 AA batteries. Optical tube Assembly weight; 11 pounds, Mount; 1.5 pounds. -
My eyepiece case (the middle one):-
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From the album: Non Astro
This is where I keep my eyepieces (The middle one). -
cell, mirror box & beginnings of upper cage assembly
perrin6 posted a gallery image in Member's Album
From the album: 200mm F6 backpack scope
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From the album: 200mm F6 backpack scope
parts cut out of 3 mm ply (BCB quality). This was done so I could cut circular parts without having to buy a router. All cutting was done with a stanley knife, circles made with a makeshift circle cutter employing a stanley blade. 4 layers of 3mm are used for the mirror box and mount. inner 2 layers of mount and inner 3 on bearings, will be skeletized to reduce weight, should still be strong enough. OTA will be about 11 pounds and consist of 7inch high mirror box, 35inch truss (12mm aluminium tubes cut in halves) and upper cage 1.1 pounds. I am mad enough to use a piece of pvc drainpipe with inner layer of milk bottle plastic as a simple push-pull focuser. This works fine on my 150mm F8 scope but will prove tricky to focus on an F6. Just couldnt find a low enough profiled focuser for the 31mm diag mirror to produce large enough fully illuminated field. (4mm - good enough for 6mm ortho which will be my main high power @ x200) -
150mm F8 planetary scope (GSO mirror)
Images added to a gallery album owned by perrin6 in Member's Album
Have had great views of Saturn, moon & double stars with this high contrast scope. Interestingly, although 100% field of illumination is only 8mm & light fall off is steep outside this, I had a v. good view of the great nebula in Orion, lots of contrasty knots and detail (using orthoscopic & RKE eyepieces) despite observing from North Adelaide. .23mm-wire spider & 22.5mm diagonal produces about 2.8% obstruction of main mirror by area and faint diffraction spikes only on stars & planets brighter than 1st magnitude. -
From the album: 150mm F8 planetary scope (GSO mirror)
15% obstruction (by diameter) of primary. .23mm wire spider produces visible on only the brightest of stars and the bright planets and spikes are quite unobtrusive -
From the album: 150mm F8 planetary scope (GSO mirror)
.23mm (.009 inch) electric guitar wire and 22.5mm edmund optics diag mirror (reflective diameter 20.5mm) -15% diameter obstruction of main mirror. Area obstruction of main mirror by diagonal plus wire is about 2.8%. Wire is attached to bits of old circuit board which is strong & I assume effects little abrasion on the thin wire as otherwise why would it be used to hold delicate circuitry !. The diagonal mirror is quoted as having 1/8th wave accuracy which isn't as good as other makes claims. I initially ordered a quartz mirror from Protostar but this company seems to have problems fulfilling orders as it took my money but provided no evidence of posting and I never received it nor any reimbursement despite polite requests by email and letter. -
From the album: 150mm F8 planetary scope (GSO mirror)
10mm wide, 1mm walled aluminium truss tubes provide sufficient stiffness to keep collimation. -
From the album: 150mm F8 planetary scope (GSO mirror)
150mm f8 GSO mirror. Quite good images of the planets and moon with v. faint diffraction spikes vis. on stars & planets brighter than about 1st magnitude. Good views of Saturns rings but little detail in atmosphere apart from orangish equatorial belt and dusky polar region. Good detail and contrast on moon with University optics 6mm orthoscopic at 200X. Have seen 12.7 magnitude stars and glimpsed 13+ mag under city (Adelaide) skies. Good on double stars too. Star images are close to refractor-like with this scope. -
350mm (13.8 in.) F5 home-made single-pole telescope
Images added to a gallery album owned by perrin6 in Member's Album
Have since added an in-lightpath kydex baffle.-not ideal as this reduces contrast but only option with this design. Left with brother-in-law in Perth (Australia). -
From the album: 350mm (13.8 in.) F5 home-made single-pole telescope
This mirror had a very poor figure when I purchased it from a well-known optical company and I was able to produce a big improvement with my first ever attempt to figure a mirror although it still has a fairly wide turned-edge and planetary detail is best seen with it masked to 320 mm (12.6 inches). -
From the album: 350mm (13.8 in.) F5 home-made single-pole telescope
Borg helical focuser is very light enabling balance point to be low, keeping mirror box & rocker box short & light. This also enables the rocker to have very short, stiff sides keeping flexing to a minimum. The Borg provides enough focusing movement for my range of eyepieces (19mm - 4mm). Finder is made using old boots 8 X 40 binoculars and shows magnitude 8 stars easily in my moderate-light polluted sky. -
From the album: 350mm (13.8 in.) F5 home-made single-pole telescope
Home made steel mirror cell to Kriege & Berry design. -
From the album: 350mm (13.8 in.) F5 home-made single-pole telescope
Quick and easy breakdown for transport (2 bolts), 2 inch diameter tube with 1/16th inch (1.5mm) inside wall diameter. Mirror box - Russian birch. -
From the album: 350mm (13.8 in.) F5 home-made single-pole telescope
New build in 2012 (inspired by Ross Sackett). Although there are many problems with this build I have no regrets at doing it because of the convenience of quick and easy setup and lightness. Problems include; Image wobbles for 5 seconds in a moderate breeze and after focusing or moving scope ; Extraneous light reduces contrast of faint astronomical objects although some kind of light baffle could be rigged up (my next project) . -
From the album: 222mm (8.7 in) F 7.3 home-made single-pole telescope.
Curved vane spider made of stainless steel 12 inch ruler from Clas Ohlsen. Primary is a Fullerscopes c1983 with 'B' grade optics Hilux recoated. I think this rating was supposed to indicate 1/8th wave optics. Whether it has or not I don't know but I'm very happy with it's performance. -
From the album: 222mm (8.7 in) F 7.3 home-made single-pole telescope.
Focuser is plastic with metal eyepiece holder but surprisingly good with very smooth movement and no mechanical vices whatsoever. Lightness of the focuser / diagonal assembly enables low balance point, small light mirror box and short rocker box keeping everything light & flexing low so only 'play' in the movement comes from the aluminium tube which is low anyway although image wobbles a little in moderate breeze and immediately after focusing.