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About Rusted

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    Star Forming

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    ATM, imaging, Solar system, photography, blogging, cycling.
  • Location
    Darkest rural Denmark
  1. Rusted

    Charity Shop Binos

    The problem with many of the binoculars I've bought secondhand is misalignment between barrels. Lay them on something safe so they stay still and then wink each eye in turn as you look at a distant object. Or [more easily] wave a card across the objectives in turn. There should be no image movement from eye to eye. My brand new Zeiss Jenoptem 10x50s went out of alignment within a month of purchase despite being treated with kid gloves. The dealer refused to get involved by claiming they had been dropped. They hadn't. So I re-aligned them myself by removing the objective protective shells using rubber gloves for enough friction. Then [very carefully] turning the wedge shaped ring in front of the lenses against each other while staring through them. Once the images overlapped again and the outer locking rings were re-tightened they have been fine for the last 30 years. Don't remove the locking rings or you could see the objectives taking a nose dive! Note: Some binoculars may not even have such wedge shaped rings. I really wouldn't get involved in prism shifting screws! You carry out such repairs entirely at your own risk. As did I, because I had no choice. If you get headaches, nausea or vertigo while or after using binoculars then misalignment is the likely cause. That's how I discovered my Zeiss Jenoptem were badly mis-collimated.
  2. Rusted

    Polishing glass plates

    Of all the things the amateur optician may attempt then optical flats are one of the most difficult. It assumes some experience with making mirrors and perhaps objective lenses first to gain the vital knowledge to proceed onto flats. The above assumes that three, normal thickness, low expansion blanks are used. Each worked upon another in a strict sequence. After allowing each blank to cool they would be brought to the [crown jewels] reference flat and tested. Plane parallel 16" both sides to at least 1/10? Why not? It would requires a stable temperature and dust free room if quality is desired, long experience at testing against reference flats under monochromatic light source. It requires enormous patience, years of learned optical working skills and great care to achieve even modest results. Don't forget that your plate will distort under gravity and you must allow for the curvature of the earth and gravity waves. The only way I know of to polish a thin flat is to polish it on a proper polishing machine with a suitable ring for driving the thin blank. How big a ring? No idea. NASA might know but I wouldn't bet on it. Polishing takes place very slowly on a pitch lap which is already almost perfectly flat. Or as near to flat as very long experience at polishing perfect flats suggests. The glass may not be weighted or it will distort. It may not be ignored while running without constant attention to the polishing medium. Automatic polishing machines will have a pump to keep the pitch lap and polishing medium from drying out. I doubt that is good enough for your needs. If you have the required qualifications, temperature regulated room, vast optical experience, vast amounts of time, a very large flat to flatten the pitch lap, a decent polishing machine and a monochromatic light source in a proper set-up for testing then why not give it a go? If you lack any of these items, conditions or personal qualities then the cost of buying your finished optical flat will seem excellent value. If you want to work your way up more gently to making large, thin, plane parallel, optical flats to 1/10th, in optical glass then perhaps you could turn your inventiveness to [say] reaching Mars, using only the expertise available on astro forums.
  3. Rusted

    Tis the season !

    Well done, Jarvo! I'd need a cooled camera to capture my LED light string. They are so dim that I only use them to mark out the inner edges of the dome in the dark.
  4. Rusted

    Things you probably missed

    It should reduce your paranoia, about being banned by Cloudy Nights, to know they have zero tolerance of "home made," "DIY," or ATM solar equipment. I was banned for simply mentioning my H-alpha telescope/PST modifications on CN. I thought I was one of the good guys too. With long threads on my observatory build and home made, heavy duty, Goto mounting and assorted home made telescopes. My reading on this subject is that they [CN] staff are terrified of being sued for any loss of sight or eye injury. Usually caused by those who attempt to emulate our mods without doing their homework first. Lazy minds cause accidents but they are protected from evolution by their ability to sue at no cost to themselves. CN is a largely US forum. Which is a country where litigation is a national sport. One enjoyed by countless no win: no costs, 'ambulance chasers.' That said, I'd like to rule out some obvious problems concerning your claims. You have several longer than average instruments, with large moments [mass x distance] but no serious mounting to handle them. How then, did you, or do you, capture your solar images and videos? You have obvious construction skills yet have avoided the obvious path to progress from building a suitable mounting for your needs. Find a couple of heavy [scrap?] shafts and some dirt cheap, Chinese, pillow block bearings to match. These can be attached to a simple [scrap] metal or [dumpster] plywood plate and mounted at your latitude on a concrete or heavy wooden post. Secondhand worms and wheels, for drives, can be obtained on AstroMart and other lists. Synchronous Drive motors are dirt cheap on eBay. There are cheaper drive alternatives like screwed rods [studs or all-threads] and radius arms for the "inventive." Hefty, vintage mountings are often scrapped or sold cheaply online through lack of interest in such older items. Many an astronomy club has older stuff donated by spouses on the deaths of members. Why not seek something suitable from an astro club contact number or email address? Stop publicly blaming everybody else for your equipment poverty! I have been equipment poor all of my life but overcame this my making stuff myself and buying secondhand. Self discipline is a major part of being a good scientist. Radiating paranoia from multiple, blazing headlamps is never a good sign! It frightens people away! Even that giant of a genius, Tesla, went bust! And I'm not talking about the other "Tesla" guy. You have to take yourself seriously to be taken seriously. That means being honest with yourself and recognizing your own weaknesses. It means sorting out your priorities and removing personal obstacles to progress. Like advertising your problems with being taken seriously by fellow amateurs. Leaders have to show leadership. Or you come across as a cult leader desperately trying to sell snake oil to lost souls. For example: Why use countless 50mm spacers when aluminium tube is cheap as chips? It seems simply profligate to waste precious funds on such utterly pointless bling [jewellery] unless you somehow got them for free! Be open to constructive advice and answer direct questions honestly. Otherwise you come across as evasive. I do hope you can cope with constructive criticism? Regards, A constructive oldie.
  5. Rusted

    Source of 1m of 8" Ducting

    I use galvanized steel, furniture factory, dust removal ducting. The stuff used by furniture factories uses straight seamed tube not spiral to avoid inflammable dust sticking to the tube. 0.3mm wall thickness steel is the same weight as most other commercial telescope tubing including carbon fiber and rolled hard paper. I've found steel tube in sizes up to 16" Ø in 2" steps so far in a furniture factory's used stock pile at beer money prices. You just have to remember to put the straight seam at the tube ring clamp or hinge but you can't easily rotate the tube. Cardboard tube needs to be kept round with well glued rings or it will go oval at a whim. I've tried it and given up. Laminating cardboard with GRP massively increases the cost and the weight and ruins the appearance. Been there, done that. Laminating two cardboard pipes over each doubles the weight, leaves a gap and it still goes oval at a whim! Plastic ducting [thinner and much lighter than sewage pipe] is fragile when cold and will split readily with a blow or from being squashed. Most plastic drainage pipes will sag in warm sunshine. They are also very heavy relative to other materials of the same Ø.
  6. What Gordon said. Goto is the difference between time wasted looking for against the time well spent looking at. Luddites came from an agricultural background where light pollution wasn't a problem and they never left the village. While city people are grateful for street lamps so they can find their dropped eyepieces before somebody steals them. Looking for is like owning a Ferrari but never leaving the garage because you are always searching for the keys. Planetarium software doesn't need a torch, while holding your out of date star map, upside down, in front of a dewed up mirror. 99% [of those who expressed an opinion] preferred looking at rather than looking for [something.]
  7. Rusted

    A Cheap Huge Worm Gear

    Anyone can highlight, then right click on your text and select Google Translate in the drop down box.
  8. Rusted

    A Cheap Huge Worm Gear

    I'd like to resurrect this thread to further congratulate the clever chap, Vroobel, who made his own wormwheels. Regarding the number of teeth on a given blank: The teeth have some depth. This puts the bottoms of the teeth at different radius to the tops. [Which is at the blank's smooth outer diameter.] So you need to calculate a smaller diameter of wormwheel blank if the number of teeth is important to you. I have often advocated the use of accurate, but mass produced, perforated strip material for dividing a blank. Roofers have lots of different perforated strip for reinforcing and triangulating roof constructions. These perforated strips could be wrapped around a large diameter blank on the same shaft as the intended wormwheel. The larger the dividing blank, the more accurate the smaller wormwheel will be due to the ratio between their diameters. The perforated strip is cheap enough to make a huge dividing wheel fixed onto cheap plywood or MDF. The wormwheel blank then needs to be gashed at the correct angle to match the tap's helix. This could be done using a home made "fly" cutter. A pointed tool passing through and clamped into a driven shaft. Or use a small metal cutting, slitting saw which are probably available on eBay. Both types of gashing tool can easily be driven with a pillar drill or electric motor. The dividing wheel gives you the correct number of teeth if this is important to you. The thread cutting tap gives you the correct profile for the teeth and will faithfully follow the previously made gashes. None of this takes away from the skill and imagination shown by our OP, Vroobel. Very impressive work indeed! Thanks for sharing your artistry. Seriously clever stuff!
  9. Rusted

    DIY rotating Nissen Hut or Pulsar 2.7m?

    Thank you all for your encouragement. The long tube 7" refractor was rather too bulky for the 10' dome. So I swapped it for the more compact folded version today. I'll add the solar refractor and a 'finder' tomorrow. It is clear here tonight so I'm off to have look at Mars before it changes its mind.
  10. Rusted

    DIY rotating Nissen Hut or Pulsar 2.7m?

    My 20' tall, 3m/10' birch plywood observatory is finally, very close to finished. Though there is always more to do. Presently housing my 7" f/12 and 6" f/8 refractors. The latter is for solar H-a. Both mounted on my home made GEM with 50mm stainless steel shafts on its 14'6" pier. Now running ASCOM-AWR Gotos thanks to the latest Platform update.
  11. Rusted

    DIY rotating Nissen Hut or Pulsar 2.7m?

    Hi James, Thanks. It must be getting quite close now. I have been so busy with the build that I haven't really thought about using the observatory yet. I just had my first rain test of the newly painted dome. A couple of small leaks high up. If I can get a second coat of paint on before winter they might just disappear. No drips though. Lots of fun yet to be had dragging the telescope(s) "upstairs" and bunging them onto my big DIY Goto mounting on its 14' tall pier. I have my 7" f/12 DIY refractor in straight and folded form. The 6" [120mm equiv] H-a DIY refractor and a 10" f/8 mirror I still need to mount properly. Now I need some dim, red LEDs to find my way about in there without banging my head on the counterweights or falling through the open trapdoor. Chris
  12. Rusted

    DIY rotating Nissen Hut or Pulsar 2.7m?

    Yet another update: Primed, painted and now working on veranda handrails. For those of you who have followed my build "in another place" I have been banned for mentioning home built, H-alpha telescopes. More details than you ever wanted continue to pour down on my Fullerscopes blog.
  13. Rusted

    DIY rotating Nissen Hut or Pulsar 2.7m?

    Just another update: Shutters on:
  14. Rusted

    Obs shutter drive: winch slipping: fix ?

    10 speed bike chains are usually coated with an anti-rust finish. Colours too, if it matters. Sprockets are readily available but with a big hole in the middle, left or right hand threads and/or oddly splined. Simply Bearings [UK] lists various sizes of "pilot hole" sprockets in 1/2" pitch.. Single, double and triple. https://simplybearings.co.uk/shop/Engineering-Parts-Chains,-Links,-Sprockets-&-Platewheels-Sprockets-Pilot-Bore-Sprockets-Simplex-Pilot-Bore-Sprockets/c4713_5487_5510_5511_7747/index.html I once used a left side, bottom bracket cup [same thread as screw-on sprockets and blocks] with a small sprocket to drive a mirror making machine. Or use a whole, threaded bike hub and sprocket if you need bearing support for a layshaft.
  15. Rusted

    Obs shutter drive: winch slipping: fix ?

    The only obvious way to ensure a flat cable lay is a heart shaped cam and actuating arm with double roller cable guide. Like an old fashioned, Singer sewing machine, spool winder. The cam has to be worm geared. It quickly gets rather complicated and may not stand up to heavy cable loads. I should have added that a cable drive ideally needs a V-pinch roller for grip. That probably means one near, full turn of cable but no more. The more wrap the better but the cable cannot cross itself.

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