January 2006 - Utah-Astronomy - mailman.xmission.com

Dovetail standards
by Chuck Hards 30 Jan '06

30 Jan '06

Guy, could I prevail upon you to enlighten us on dovetail standards for reflex sights? I noticed that the Guide Gear sight uses a much wider dovetail than the Gamo, Orion, and Mars-eye. TIA __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Re: Mosquito Repellants
by Chuck Hards 30 Jan '06

30 Jan '06

No chemicals at all? So much for soap, sunscreen, antiseptics...water... If you weren't so sweet, the mosquitos would leave you alone! ;) They never bother me, for some reason. Now deer flies, on the other hand, see me as a smorgasborg. I've actually lost weight after a deer fly attack! :( > From: <astrodeb(a)charter.net> > I've come to the conclusion that I do not want to > put any chemicals on my skin. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Re: Dovetail standards
by Chuck Hards 30 Jan '06

30 Jan '06

Thanks, Rob, (and Guy), but before the digest came through I had already made a foot of each size dovetail on the table saw, from 1/8" aluminum plate. Easy, and cost nothing at all since the plate came from the scrap bin. Sounds like between Guy and me, we can outfit everyone on the list no problem. I am going to mount the dovetail plate to the top of the C bracket using #6 or #4, countersunk flathead machine screws. Then I can just swap them out if needed. I agree with Guy that double-sided tape isn't a good way to go with a $50 sight. I have a feeling I'll stick with the Guide Gear sight on the 25x100mm, and the Mars-Eye or Gamo sights on the smaller binos. I may get another Guide Gear sight to mount on the big telescopes, as well. To date, besides the binos, I've only used a reflex sight on my small refractors, but that Guide Gear/Burgess sight is one neat unit. > From: Rob Ratkowski <ratkwski(a)hawaii.rr.com> > You'll have to get the proper dovetail from Burgess > Optical > http://www.burgessoptical.com/Accessories/MRFBase.html > Two types > a flat base w/dovetail grove ($9) and a taller > dovetail that is the > flat dovetail double sided taped to another thicker > dovetail section > (Orion/Vixen style $12). The Vixen style offers > both bases if > needed, just remove the flat dovetail from the > assembly and is more > price effective. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Mosquito Repellants
by astrodeb＠charter.net 30 Jan '06

30 Jan '06

Hi, I was reading in my book "Introduction to Digital Astrophotography" and I came across the section about Mosquito Repellants and Traps. I'm concerned about the the safety of using these products due to a health condition I have. Let me quote what the author Robert Reeves says about the safety of using repellants that use the chemical DEET. "However, the safety of DEET has been questioned, leading the Environmental Protection Agency to review the product. Their conclusion was that "normal use of DEET does not present a health concern to the general U.S> population." DEET has been classified as less toxic than many people believe and adverse effects are traced to gross overuse of the product. But still, the wisdom of slathering yourself with a chemical that is toxic enough to be offensive to other living beings is debated with some vigor. Logic suggest that if the chemical is that potent, it can't be good for the person wearing it either." I've come to the conclusion that I do not want to put any chemicals on my skin. Therefore I'm looking for a more natural substitute to protect myself from mosquitos. Last July, I got over 50 bites while observing at BlackRock Rd in AZ. Hence, I'm wondering how to safely protect myself. Any ideas? Debbie

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Re: An Astronomer's Song (sort of)
by Chuck Hards 30 Jan '06

30 Jan '06

Yeah, Guy, since I've had the LP for decades I knew it was about a vampire...(a metaphore for Nilsson himself, really), but since we share a love of the night with those bloodsuckers, I just couldn't resist... Years ago I saw Bruce Lindsay of KSL attempt to interview Harry Nilsson on channel 5. Nilsson came out stinking, incoherrently drunk- a typical state for him near the end of his life, sadly. But at the time I was laughing my butt off. Bruce was obviously flustered, and they quickly cut to a commercial. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Re: Re: Re: Re: The promise of spring
by Chuck Hards 30 Jan '06

30 Jan '06

LOL, a Klingon cantata about a robotic snow-blower!!! I dare you- I triple-dog-dare you. Of course, the risk is that, THAT'S the one history will remember you for! > From: Michael Carnes <MichaelCarnes(a)earthlink.net> > Thought you'd go for Klingon... > > On Jan 29, 2006, at 8:53 PM, Chuck Hards wrote: > > > Only in Esperanto or Volapuk. > > > >> From: Michael Carnes > <MichaelCarnes(a)earthlink.net> > >> > >> You wanna sing it? __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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An Astronomer's Song (sort of)
by Chuck Hards 30 Jan '06

30 Jan '06

Daybreak by Harry Nilsson Here comes the daylight It's makin' me sad Here comes the sunlight Makin' me sad Had a good time last night Best I ever had Here come the sunshine That's makin' me sad So sad, so sad, so sad, so sad Here come the daybreak It's bringin' me pain It's causin' me heartache I wish it would rain Had a good time last night Just me and my friends But here come the daylight And now it's the end Oh no, oh no, oh no, oh no Here come the daylight It's bringin' me down Causin' me heartache It's spinnin' my head around, yeah Here come the daybreak It's bringin' me pain It's causin' me heartache I wish it would rain Had a good time last night Just me and my friends But here comes the daylight And now it's the end Oh no, oh no, oh no, oh no Here come the daylight It's bringin me down It's causin' me heartache It's spinnin' my head around, yeah Here come the daybreak It's makin' me cough It's causin' me sunburn It's p*ssin' me off Had a good time last night In the moon's glimpse Now all that'll save me Is a total eclipse Oh no, oh no, oh no, oh no... __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Re: Parallelogram rule of thumb
by Chuck Hards 29 Jan '06

29 Jan '06

Hi big C: You can keep the parallelogram accuracy good-enough by assuring two things: First, that both the central pivot bracket holes and the upper bracket holes share the same offset relationships. Using one as a drilling jig for the other can help keep the hole spacing and offset from vertical (if horizontal displacement is used) identical. The other is to make sure the hole spacing in the arms themselves is identical. Drill one arm first, then use it as a drilling guide for the other, that way the spacing is the same on both arms. For both the arm and bracket drilling procedures, clamp them together to keep them from shifting during drilling. Make sure you drill the holes square to the assembly. A drill press helps. For a central azimuth pivot, I resorted to Dobsonian technology. The central pivot bracket uses a solid block of hardwood with a 3/8" hole bored all the way through it. The bottom of the block has a piece of Ebony Star glued to it, and this in turn rides on a ring of Teflon. I hacksaw the head off of a 4" long carriage bolt and bolt it to the top of the tripod with the 1" threaded section. The unthreaded section then serves as the pivot bolt and the azimuth bracket is slid over the top of it. I'll send you some images shortly. The bolt is from the hardware store and I have lots of Teflon and Ebony star if you can use the method. > From: Canopus56 <canopus56(a)yahoo.com> > Another test of two-user convenience (that mine > mount > fails) is how finely the parallelogram is > fabricated. > With good machining, I understand that when the > mount > is slewed to a new user at a different height, it > should remain reasonably on target, e.g. - > "reasonably" meaning within a few degrees. > > Another problem that I failed to solve in > fabricating > my parallelogram bino mount was off-the-shelf > hardware > that would allow a rotating base. Chuck, what > solution did you use? __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Re: Re: Re: The promise of spring
by Chuck Hards 29 Jan '06

29 Jan '06

Only in Esperanto or Volapuk. > From: Michael Carnes <MichaelCarnes(a)earthlink.net> > > You wanna sing it? __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Parallelogram rule of thumb
by Chuck Hards 29 Jan '06

29 Jan '06

A question asked me in a recent email seemed rather important so I thought I'd post my answer to the list in case anyone else was working on a parallelogram. Namely, how long to make the arms? A few things to keep in mind: You want to be able to view directly overhead when standing, without having to "scrunch down" at all. Any kind of stooping to get under the binocular when it's pointed overhead will cause muscle fatigue and strain, and defeats the purpose of the parallelogram. I also like to add a few inches for folks a bit taller than I am. I'm 5'-11" in my shoes, but I have good friends in the 6'-4" range so making it tall enough for them as well is a nice gesture. All of the height doesn't have to come from just parallelogram arm length. Excessively long arms will lead to an overly-long damping time for natural oscillations and vibration inherent in cantalevered or balanced structures. Some of the height can be achieved with the tripod or post it is mounted on. But also consider those times when you want to observe seated or reclining in a lounger- the arms can't be so short that the binocular can't reach low enough. Again, the tripod can help by being adjustable to this lower limit, but it is a nice feature if most, if not all, of the minimum-to-maximum height range can be accommodated with just the parallelogram arms themselves. At least try to maximize this range and then leave the remainder for an adjustable tripod, if necessary. Sometimes at star parties I will set up two parallelograms, one for a greater height reach than the other, to accomodate everyone without having to re-adjust tripod legs in the dark. Back to chair or lounge observing for a moment. If using a parallelogram for this style of observing, it is mandatory that the design have pan capability right at the binocular, and not be completely reliant on the central pivot atop the tripod for azimuth changes- otherwise your chair had better have casters because you'll be constantly rolling around the tripod to stay under the binos. Hard to do in the field in most cases! I suppose you could set your chair on a mechanics "creeper", on a concrete surface, otherwise design-in some pan capability at the bino end of the arms. Hope this helps. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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