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Paladin

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About Paladin

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    Nebula

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  • Gender
    Male
  • Location
    South-east Essex, UK
  1. Hi Steve, I’m afraid I can’t give you any information on present day mirror supplies, but thought I would post, as your mirror making history nearly echoes that of my own. I constructed my first telescope, a 6 inch f8 Newtonian, when I was a teenager in the mid-nineteen-fifties. I had to save up the money from my holiday job to buy the mirror assembly from Brunnings of High Holborn in London for £5.0s.0d! I constructed the scope and mounting out of wood, but did not make a very good job of it, as it did not perform as well as I had hoped, so I soon lost interest and eventually sold the
  2. Chris: You mention that the classic Dob uses Teflon and Ebony Star for bearings, a system set out by Kriege & Berry in The Dobsonian Telescope, which I assume is the source of your statement. However, you are wrong to suggest that no polish should be used, as after experimenting, they concluded that it could help in achieving the optimum ‘stiction’. Chapter 13 of the book describes building a simple 8 inch Dob, and was a huge influence on the design of my own scope: http://stargazerslounge.com/topic/255887-8-inch-dob-finished-at-last/ The following is a direct quote from that chapter: "
  3. Thank you all for your kind comments. Merlin: "It will be interesting to see how the material stands up to our humid climate". All wooden parts received 2 coats of Cuprinol wood Preserver before 3 or more coats of marine varnish, so it should survive the British weather. Although the intention is to eventually keep the scope in the garden shed, at the moment it resides in the living room, where my wife is treating it like a piece of furniture. Luckily it has escaped the Christmas tinsel treatment so far! Best wishes: Paul
  4. "I added more felt pads further out but this reduced it but not fully". Beamer, I suggest that you use only 3 pads placed as far apart as possible to get a rigid mount. The classic dob design always uses 3 as any more will always cause rocking. Paul
  5. Since I started this thread, I have found an interesting passage in “Patrick Moore on the Moon” written in 2001, in which Sir Patrick mentions the debate at the General Assembly of the International Astronomical Union when they attempted to reach a consensus when referring to the orientation of the Moon. Being a traditionalist, Sir Patrick argued for the well-established classical view with south at the top, east on the left & west on the right. The vote subsequently went against him and in favour of the naked-eye view with north at the top, but with west on the left and east on the righ
  6. “Why’s it upside-down, Mister?” is the age-old question asked when someone looks through an astronomical telescope for the first time, normally when viewing the Moon. The usual answer was that there is no up or down in astronomy and to get the image the right-way-up would involve using more lenses which would reduce the light gathering power of the scope. It therefore became the convention to publish all astro photos as inverted images as a result, and lunar maps were always orientated with south at the top. Checking through my small collection of astronomy books, I find this was the case u
  7. First light at Last! Clear skies tonight meant that I finally managed to use the scope in earnest, but only on the moon. I was quite pleased with the result although there is still work to do on the mount because there is still too much ”stiction” on the altitude bearings. I think it is only a matter of experimenting with various polishes to find one which will give the right amount of friction. I am open to suggestions if anyone has had the same problem. Ideally, the amount of effort needed to move the scope should be the same for both the altitude and azimuth bearings. Because of the j
  8. Hello all In my last post, I listed various mods to be carried out before a proper first light, and although most of them have now been done, the rotten weather has prevented any visual testing. The elderly mirror has now been cleaned, and although it looks a lot better than it was, I’m slightly disappointed with it, and it really ought to be re-aluminized, but that will have to wait for now. Anyway, as Basil Fawlty says "it’s not in absolutely mint condition, but it could certainly be used in an emergency". To cut down on reflections I have flocked the inside of the focuser, and have al
  9. Update Thanks to everyone for their complimentary comments about the Paladin Dob, I really appreciate it. Although I admit that I’m rather pleased with how the scope turned out, I can assure you that my craftsmanship is not as good as some of you have suggested, as there are many things which I wish I had done better. However, as the first pics were received so well, here are a few more. As I had decided to clean the mirrors properly before final assembly, I collimated the scope only roughly, because I was waiting for my order of distilled water to arrive. However, on Wednesday evening
  10. The Mount I wished to incorporate some of my own ideas in the design of the mount; particularly with regard to the cradle which clamps the OTA to the altitude bearings, as I think it can often look too “boxy” in some designs. My solution was to construct just the bottom half of the cradle, and to clamp the tube with bands of flexi-ply using over-centre clips. The base and gussets of the cradle were made from 15mm and the sides from 7mm. Self-adhesive felt pads were fixed to the cradle and the flexi-ply bands to give the tube a snug fit, but also allow the position of the tube to be adjuste
  11. Optical Tube Assembly As the scope is to be stored in the Summer House, (aka garden shed), I decided to make the tube solid so that it would be easier to keep any moisture out. When my sister bought a sheet of 5mm flexible plywood to repair a curved stairway in her home, she had quite a sizable amount spare which she kindly donated to the project. Unfortunately, as the piece wasn’t quite wide enough, the tube had to be made in 2 parts which were formed around several wooden hoops and a wooden backbone down the full length. The short extension of flexi-ply was added to the top of the tube,
  12. The construction of my home-made Dobsonian is now almost complete after a lengthy gestation period, so here is the story of its construction. Some years ago, when I decided to build a telescope, I ordered a copy of The Dobsonian Telescope by David Kriege & Richard Berry from the States. After reading the book, I came to the conclusion that a simple design, as described in chapter 13 would be more appropriate for me, rather than a truss tube design which I had previously planned. I bought a second-hand Hinds 8 inch f6 mirror via UK Astronomy Buy & Sell, and also accumulated other i
  13. Hi I have got 2 books on eBay at the moment which should interest SGL members. I can post only to UK addresses. The Dobsonian Telescope by David Kriege & Richard Berry, eBay Item number: 260953333172. Build Your Own Telescope by Richard Berry, eBay Item number: 260953345578 Both books are not easy to get hold of in the UK. Both auctions end on Sunday 19th February, just after 5 pm. Please have a look. Regards Paul
  14. Ive just noticed this on ebay. Although a bit old now, these books were THE Bible for amateur telescope makers. Amateur Telescope Making - 3 vol - Scientific American on eBay (end time 08-Dec-09 19:09:48 GMT) Item No. 230405400813 No bids so far but there are still nearly 10 days to go. They might fetch quite a bit, though. Paul
  15. 10 refers to the magnification and 50 is the size of the main lens in millemetres. Paul
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