Hi Gil, Actually, I have used a 10" F/4.5 newt with a Baader MPCC along with my Orion 6mp Color One Shot with very good results. I used an oversize diagonal...
Hi gang: Just a quick note to let you know I've posted an article on how to figure out the "correct" size of a Newtonian reflector's secondary mirror. I get...
Hi, I am building an 8" dob, to locate support points for mirror (cell) at 40% of radius. If my figures are correct that would put my points at 2.4" radius...
Paul, The 120 spacing is correct, but the 2.4" radius is not. The radius of the mirror is 0.5*8"= 4", so 40% radius is 0.40*4"= 1.6" radius. So the three...
Yust click the link under Gary's name, Ken. Jan http://members.ziggo.nl/jhm.vangastel/Astronomy/ ... From: Ken Hunter To: atm_free@yahoogroups.com Sent:...
Crazy interrogation I have it yesteday nuight how we can know what day we are when we are on the moon the important info is: are we one or 2 day before the...
Hi Hyades looked attractive. A double off Aldebran was cute. The whole cluster was a little smaller than fov and formed a V shape. Pleiades were low and thus...
Thanks jan for the reply. I figured backwards subtracting 40% or multiplying by .6 thinking exactly what you said, that the point would need to be out farther...
Hi Paul, 120 degrees is right of course. When I multiply 4 inches by 0.4, I get 1.6 inch radius. It is figured on radius, not area. In pre-Plop days, the...
... It is true that 40% is a poor radius to put alignment screws at, because the sensitivity is high. Remember, there is no reason at all that support points...
Thanks mark,I like that idea and now remember seeing it online and will incorporate it into my design. My uncle built his own 30 years ago and I always wanted...
The 71% solution is a notional approach that is a "makes sense" first approximation. It is much more applicable to a ring of support than to 3 points (it's not...
The old 71% approximation was not altogether silly. The farther out you place the points, the more "trefoil" deformation; on the other hand, the closer to...
ok maybe I am not clear my english is so so this edeal come to from and other post the one asking for where is your prefered place to land on moon but after...
Thanks for all your eyepiece advice - really helpful. Having spent the last few clearish nights experimenting, I think I have a better handle on the problem. I...
I am interested in the reply too. ... From: Chris Pearse To: atm_free@yahoogroups.com Sent: Sunday, April 05, 2009 6:03 . Subject: [atm_free] Primary glass...
Many have tried. Success has been essentially zero, except by using a kiln to heat the glass to near melting temperature. This can work, but it isn't an easy...
Nice tool Nils. Mirror edge support effects are seldom mentioned. I think it may be hard to predict in individual cases. The more points, the closer the...
houp!!!! it is between some problem whit translation and some aphasiia at the keyboard after a big anestesia I hope you untherstand now it is a technic of...
There was a 40" that showed up at last year's Oregon Star Party built from fused 1/4" plate glass. Looked promising (not completely figured). Mel Bartels ... ...
Hi everyone: I got a couple of requests for this, so I've posted my article on building an easy binocular mount. The "Easy-Go-Round" can't do everything that...
When you say the glass was fused, do you mean melted together or glued together with some sort of bonding cement. If the latter, would a reflective coating...
Fused = bonded together by fusing (no glues). So grinding through the layers is not a killer because it's all basically glass of the same CoE. Mel Bartels. ...
My conclusion today, from decades of considering the problem and experimenting with building mirror mounts with attention to edge supports for a number of...
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