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Messages 365 - 394 of 853   Oldest  |  < Older  |  Newer >  |  Newest
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365
Chamfering mirrors is a common practice, urged by pros to minimize the prospect of chipping. I am in the process of designing an instrumentation port that is...
Art Bianconi
artbianconi...
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Apr 15, 2009
1:30 am
366
Is a chamfer usually a flat angled surace between two flat angled surfaces? I think a gentle curve with no angles between the two surfaces would be likely less...
Peter De Baan
pdebaan
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Apr 15, 2009
2:54 am
367
... Art: There is a spec on the angle between two surface (like the spherical surface of a lens or mirror and the outside diameter) in MIL-O-13830A and is was...
mpate747
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Apr 15, 2009
6:51 am
368
Art, The name of this effect is called the "Twyman effect" caused by stress relief in the glass you are grinding. I haven't read much about it, don't know how...
Ed Jones
opticsed
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Apr 15, 2009
11:57 am
369
any info on how many different types of unobestructed telescopes that worked good? thanks for the group // kevin frederick...
airfrederick
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Apr 15, 2009
6:24 pm
370
... Kevin, There are a whole bunch of unobstructed telescope designs that work at least on paper or by raytracing. I've posted a number of them in the files...
Ed Jones
opticsed
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Apr 16, 2009
1:38 am
371
You are correct Peter: a radiused fillet is a common method for reducing the concentrations of stresses normally found at a vertex. If one is dealing only with...
Art Bianconi
artbianconi...
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Apr 17, 2009
3:20 am
372
Thanks for the reference Michael. I appreciate the effort you expended in researching it. Before I had the chance to calculate the chamfer, the client popped...
Art Bianconi
artbianconi...
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Apr 17, 2009
3:26 am
373
To: spiderless@yahoogroups.com From: artbianconi@... Date: Fri, 17 Apr 2009 03:19:28 +0000 Subject: [spiderless] Re: Whats the name of the principle...
Peter De Baan
pdebaan
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Apr 19, 2009
3:13 am
374
That's it! "The Twyman Effect"! BTW, there is a four to six week wait on the structural foam I'm using in the composite panels (3/8" Divinycell 3 lb density)....
Art Bianconi
artbianconi...
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Apr 19, 2009
2:02 pm
375
That's it! "The Twyman Effect"! BTW, there is a four to six week wait on the structural foam I'm using in the composite panels (3/8" Divinycell 3 lb density)....
Art Bianconi
artbianconi...
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Apr 19, 2009
2:02 pm
376
How do you test the quality of the CHief lenses? Before they closed down our plant I could just use the interferometer and lenses at work. I have an...
Ed Jones
opticsed
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Apr 22, 2009
6:07 pm
377
It could happen. I recently purchased a Dell lap top. The incentive to do so came when I chose to get my feet wet with imaging. Since planetary work is where I...
Art Bianconi
artbianconi...
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Apr 23, 2009
6:01 pm
378
Hi Art! You will like an equatorial platform, they are great and easy to make. On mine I used 2 synchronous motors $19 from Herbach and Rademan driving 2...
Ed Jones
opticsed
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Apr 25, 2009
3:08 pm
379
Hi Ed! Why two synchronous motors? I know the DC to AC inverter you speak of. I remember the mods you shared with us at CN. I bought two of them for myself but...
Art Bianconi
artbianconi...
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Apr 26, 2009
2:35 am
380
Hi Art! I use two motors because they are relatively cheap but mainly because if I use different scopes with different balance points one motor can slip if the...
Ed Jones
opticsed
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Apr 26, 2009
5:12 pm
381
HI ed thanks for all the info //Can the using the test that uses a led at 100 ft and the small lens be used to test complete CHief // thanks for the test on...
airfrederick
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Apr 27, 2009
11:23 am
382
The two mirrors on my 6" Schiefspiegler are tilted in a fashion similar to yours and thus provide obstruction and defraction free images with excellent...
Art Bianconi
artbianconi...
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May 3, 2009
4:13 am
383
There has been so much positive dialogue about the performance of Ed's CHiefspiegler design that something positive appears to have been overlooked. IMO,...
Art Bianconi
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May 3, 2009
4:41 am
384
Hi, Art. Yes, the absence of an upper cage assembly and large elliptical flat (I assume that's what you're point at) is an attractive feature of a Chief. The...
roger ceragioli
apoachroroger
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May 3, 2009
5:05 am
385
Roger, If you ray trace Herschel's 18 inch scope it has a horrible image yet we know Herschel was observing very fine detail much better than we should expect....
Ed Jones
opticsed
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May 3, 2009
2:38 pm
386
Ed, Yes, many eyepieces have been measured. Almost all are simple biconvex or planoconvex singlets. One Huygens (William Herschel disliked Huygens...
roger ceragioli
apoachroroger
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May 3, 2009
3:16 pm
387
Art, The Kutter uses the secondary tilt to reduce the astigmatism and coma of the tilted primary. Unfortunately the tilts need to correct the astigmatism and...
Ed Jones
opticsed
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May 3, 2009
3:25 pm
388
Roger, Very interesting that he had some negative singlet lenses! Any mention of how he used the negative lenses? Can I get a copy of your paper when you...
Ed Jones
opticsed
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May 3, 2009
3:39 pm
389
Hi, Ed. I'll send my ATS powerpoint presentation in a few days. Please send me your private email. The formal paper will not be finished for some months. He...
roger ceragioli
apoachroroger
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May 3, 2009
4:24 pm
390
I was going to wait until people responded to the added lead weight issue before bringing up yet another CHief advantage, but yes, as designed by Kutter or...
Art Bianconi
artbianconi...
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May 3, 2009
6:51 pm
391
I'm getting ready to try my lens curve generator. A friend made me a spindle I could put on my drill press base to spin the lens. My drill press head tilts to...
Ed Jones
opticsed
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May 3, 2009
11:53 pm
392
The CHief idea has me thinking of redoing a scope I currently have... I have an 8" f5.75" mirror. Of course the idea of 8 inches unobstucted appeals to me. I...
timo4352
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May 4, 2009
11:35 pm
393
i have a small magnetically mounted spritzer that sticks to the arm above the table on my milling machine. It has a small regulator screw to adjust the amount...
Art Bianconi
artbianconi...
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May 5, 2009
2:27 am
394
welcome  you are at the right group  if you wont to make a CHief // kevin frederick ... From: timo4352 <timo4352@...> Subject: [spiderless] Where to...
kevin frederick
airfrederick
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May 5, 2009
2:32 am
Messages 365 - 394 of 853   Oldest  |  < Older  |  Newer >  |  Newest
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