LeeB Posted May 7, 2013 Share Posted May 7, 2013 Converted an old 10mm skywatcher eyepiece to a reticule yesterday, what a difference to tracking accuracy, three star align and a decent polar set up, the mount hit everything with 10% of centre at 160x, all for a couple of hours work and a hair from my daughters head. Link to comment Share on other sites More sharing options...
michael.h.f.wilkinson Posted May 7, 2013 Share Posted May 7, 2013 Sounds interesting. How did you attach the hair and get it centred? Link to comment Share on other sites More sharing options...
JamesF Posted May 7, 2013 Share Posted May 7, 2013 Yeah, go on. Spill the beans Bonus points for posting pictures...James Link to comment Share on other sites More sharing options...
Peter Drew Posted May 7, 2013 Share Posted May 7, 2013 I made hundreds of human hair crosshairs during my career and have a sizeable bald patch to show for it. I taped the hair to the eyepiece, centred them by eye (they don't have to be exact, the cross point is the reference) and then applied some adhesive before removing the tape. You sometimes have to adjust the field stop to bring the hairs into focus. Link to comment Share on other sites More sharing options...
Grotemobile Posted May 7, 2013 Share Posted May 7, 2013 That is one bit of kit, i would notbe without now.Got mine for £20,s/hand.Steve. Link to comment Share on other sites More sharing options...
michael.h.f.wilkinson Posted May 7, 2013 Share Posted May 7, 2013 I made hundreds of human hair crosshairs during my career and have a sizeable bald patch to show for it. I taped the hair to the eyepiece, centred them by eye (they don't have to be exact, the cross point is the reference) and then applied some adhesive before removing the tape. You sometimes have to adjust the field stop to bring the hairs into focus. I did do something similar, but always found it very fiddly. I will give it a shot on my Antares 25mm 70deg EP Link to comment Share on other sites More sharing options...
Macavity Posted May 9, 2013 Share Posted May 9, 2013 Just wondered what the thickness of human hair was... 40 - 250 microns, apparently. We used to use a lot of Wire chamber detectors (don't worry overmuch). But those used thin wires, made from various materials, in the range 20 to 150 microns. Handling 20 micron was strictly for the experts! But 30 microns was just possible - 100 Microns, almost a doddle? (It has a useful "stiffness" factor!). I see it's possible to obtain:http://www.wireandst...tres--2406.html <shrug> A lifetime's supply for a couple of quid? Wire can often stand a fair few grams tension! Some materials are better than others - Apparently Aluminium tends to slip through adhesive, 'cos of the oxide layer. Maybe use what we did... Get the gold plated stuff? Link to comment Share on other sites More sharing options...
Peter Drew Posted May 9, 2013 Share Posted May 9, 2013 We made some very good crosshairs from glass. A glass stirring rod was heated in the middle until molten and then the two ends were rapidly pulled apart. This left a very fine glass hair which was uniform in thickness and rigid and straight. With a bit of practise it could be snapped to length. Interestingly, as they were transparent, the edges produced double lines. A star was diffracted when centred on the cross. Link to comment Share on other sites More sharing options...
Scott Posted May 9, 2013 Share Posted May 9, 2013 Converted an old 10mm skywatcher eyepiece to a reticule yesterday, what a difference to tracking accuracy, three star align and a decent polar set up, the mount hit everything with 10% of centre at 160x, all for a couple of hours work and a hair from my daughters head.And your daughter doesn't mind standing out in the cold all night?..... what a trooper Link to comment Share on other sites More sharing options...
Chris Rowland Posted May 9, 2013 Share Posted May 9, 2013 I've done this as well, using superglue to hold the hairs (mine). It works well.The trick is not to take the EP out or rotate it during the align process so the reference point doesn't change.Chris Link to comment Share on other sites More sharing options...
DMA Posted May 15, 2013 Share Posted May 15, 2013 HelloFound this illuminated eyepiece http://tinyurl.com/c5hcrz4 don't know if any good but sound like a good idea.Dave Link to comment Share on other sites More sharing options...
michael.h.f.wilkinson Posted May 15, 2013 Share Posted May 15, 2013 I just turned an Antares 25mm 70 deg into a reticule EP, by adding two hairs of mine (little bits of duck-tape did wonders). The Antares 25mm 70 deg allows you to unscrew the barrel, attach the hairs to the top of the barrel, which, when screwed back in place makes them sit snugly against the field stop. The inner diameter of the EP housing is 35.4mm, so I must say I was tempted to buy one of these:http://www.maxlevy.c...fm?ProdID=AA068However, I am not sure what the shipping costs are (could get them by logging onto their shop, which caused the browser to throw up an "expired certificate warning" so I left it at that). It still would be the neater solution. Link to comment Share on other sites More sharing options...
L8-Nite Posted May 16, 2013 Share Posted May 16, 2013 Awhile back I purchased a used eyepiece which had a crosshair insert. Though I have not seen one before, the seller said it was from "Tal". It threads into 1.25" eyepieces and comes to focus in those of 9mm and lower power. An item worth looking for, here are a couple photos of it. Link to comment Share on other sites More sharing options...
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