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Posts Made By: Steve Hollenbach

October 1, 2009 12:36 PM Forum: Eyepieces

Wide Field vs Magnification

Posted By Steve Hollenbach

With the addition of the 13mm Ethos to my collection late last spring, I find that the long focal length eye pieces I use for wide field have their place, and the short focal length ones for magnification have theirs.

In my case with a scope at 2670mm focal length, the 13mm Ethos does a little of both. I would not recommend using the Ethos design to maximize the TFOV when it's a smallish object being observed. However it's a really useful tool in keeping that object or its associated objects in view.

For example, on clear still nights, the 8mm Radian gave me a very good view of Jupiter, but without the moons. The 13mm Ethos displayed the planet very well, but included the moons. I'm sure a 10mm would have done as well. So in that regard the TFOV comes in handy.

If your goal is to observe a very large object, say the Double Cluster (at least in a long focal length scope) then the super wide TFOV of an Ethos puts your eye in the middle. The stars you hoped to see are there, but not well framed. You have to let your eyeball wonder around.

In that case I'd opt for the long focal length EP, and get a more enjoyable view.

For those with fast scopes, the Ethoi have a clear advantage.

For my slow poke Mak, the 13mm fills a niche, but does so very well.

Thanks,
Steve

November 5, 2009 03:28 PM Forum: Maksutovs

where do we go from here?

Posted By Steve Hollenbach

I've done about all I can to make my Meade 7" MAK the best it can be. One of my brothers asked, what's the next step up? Hmmm... Good question.

First some perameters:
I can deal with the focal length, but any scope to replace it would have to have either a similar or shorter focal length. Any replacement would have to offer excellent optics with a larger aperture.

I've seen a 7" Questar and think it's good, but for that same $10,000 US, I was wondering what anyone else has had experience with.

Intes Micro makes a nice 10" MAK they sell through Teton. While I was on their web-site I looked at some radical R-C astrographs from ATM. Again within or close to the projected $10 K and larger aperture.

No I don't have that much burning a hole in my pocket, but am curious if anyone has seen larger MAKs or at least Richey's with highly rated optics.

Thanks,
Steve




November 9, 2009 06:41 AM Forum: Home Observatories

Steps one and two

Posted By Steve Hollenbach

Hi All,
I managed a few photos. Here's one. What you can't see is a three foot ball of concrete underground. The site as shown is ready for the second pour. You'd have to look hard for the details, but the site was leveled then a layer of clean sand added to help isloate the floor from the pier, then some foam filler, then a center "leave-out" and a ring form shimmed to as close to level as possible.


I might include these in an article, so more photos can be shown in sequence.More to follow.
Thanks,
Steve



November 9, 2009 10:16 AM Forum: Religion

Gods and personalities

Posted By Steve Hollenbach

The age old question "Why..." or if you like "What if..."

Just some food for thought. Why assume God is asleep or that "he" is a personality at all? Or.. What if.. God were absolutely substantial and not hiding, but still in the most obvious place?

Forgers of steel, Monkeys, Elephants, Bulls, Lightning strikers, Four-armed Destroyer or men who rise from graves...all sound like the products of "B" movies to me.

More thoughts... No old man on a throne, no vengeful dictator of law, nor a magic healer, just you... alone in a very big world, yet that very big world challenges you quite personally.

I don't know; maybe ya hafta be psychotic to think of it that way. Of course in an insane society a sane man would be thought of as insane.

;-)
Steve

January 11, 2010 08:47 AM Forum: Home Observatories

Some progress

Posted By Steve Hollenbach

Hi All,
I made some progress after a long break from just before Thanksgiving till now. My Exploradome is nearly ready to be lifted into place. The framing is partly done. I was going to use corugated metal for the outer walls, but it would be very hard to mount without some framing to hold it in place.

I'll attach a photo soon, but in a nutshell:

I used 2x3 lumber cut to 6 foot lengths (18 of them) 1 4x8 sheet of plywood cut into curved strips to be used as the base plate and crown. I needed a wooden ring. The studs were screwed and glued to the plywood strips three at a time. It looked like I was building six rocking chairs. They were tilted up and pretty much follow the curve of the round base slab, but about an inch inside that diameter. The studs ended up about 16 inches on center, but are flat to the wall, not perpendicular.

The plastic ring is in place but still not perfectly round. I'll have to lift it out, put some preload on the wood ring formed by layers of plywood, then force it to conform to the shape of that ring. The other method of deforming it's shape into a circle is cabling and shims to place greater inward pressure at the wider points. Keep in mind it is now only about half an inch out.

I agree with using more wheels, and intend to pick up a few here in town. They are not all that uncommon.

More news and photos soon. Oh...Andy, feel free to call. I'm still working killer hours, but I'm alive!

Thanks,
Steve


January 12, 2010 11:59 AM Forum: Equipment Talk

Gemini Conversion

Posted By Steve Hollenbach

Losmandy has a Gemini retrofit for adding goto to their popular mounts and to the very similar CI-700. I happen to have the CI-700, and consider it to be a good quality mount. I've been reading about the Gemini servo drive system, and it sure looks good. It touts the ability to compensate for periodic error. It costs a bit more than a chunk of change.

Does anyone have experience with adding one to their mount?

Thanks,
Steve

January 22, 2010 12:31 PM Forum: Home Observatories

Did you know?

Posted By Steve Hollenbach

Can you use a laugh?
Did you know a dome can walk, assisted only by high winds. My Exploradome is more portable than I thought. We had some wicked high wind yesterday and last night. I heard strange sounds and looked out the window to see my unfinished dome heading north!

It sort of looked like a big white bowl rocking back and forth but making slow progress accross the yard. That's a strange thing to see in the dark.

About five minutes of wrestling got it to the lee side of the house. I must finish the walls of the observatory and get the dome mounted! Work sucks; I want to play.
Steve


January 28, 2010 11:22 AM Forum: Home Observatories

Some more progress

Posted By Steve Hollenbach

Here is an overall view of a more cluttered spot in my yard. It shows the observatory with framing and interior walls in place. The skin on the walls is thin 1/8 inch masonite. That doesn't sound very strong, but once you put a curve on it and screw it to a frame it's great. The exterior gets the same thing only with the fuzzy side out. Stucco will have to stick to it. I'll also use some chicken wire.

The ring was screwed into each of the 19 studs. 16 inch centering did not work exactly well, as I had to provide a door and pre-fab them onto plywood cut to a curve. As you can see I used 2x3 not 2x4 lumber and cut them down to 6 feet.

As you step up into the circle, you have to duck very little. Well I don't but most of you might. I just didn't like those little four foot doors. Besides the horizon's not very good seeing in the 'burbs anyway.

Each stud is glued with liquid nails and screwed tight with two 1 3/4 inch drywall screws. The plywood is overlapped and screwed together, but not glued, it had to be a little flexible to allow for adjustment.

More on that to follow,
Steve
8)

February 1, 2010 03:10 PM Forum: Religion

Needs of an open society

Posted By Steve Hollenbach

Hi All,
I didn't care to dig into the 60 plus exchanges on the last thread. Maybe I missed some good ones. However, I've been re-reading the Constitution and have an open ended question for your considerable consideration and more amusement.

The question's premmiss can be based either within our Constitutional democracy or in any society considering itself to be enlightened and free. I'm giving the USA some lee way here Patriot Act, Big Brother and modern day Gestapo tactics set asside for now. Yes, that's a whine.

How should a society steeped in the traditional mainstream Christian religions handle the inflow of those of another mainstream faith, or expanding numbers of those who follow no organized faith?

In other words what would you say is a good base-line for the moral characture of a nation? Do we use the ten comandments or make a list of basic behaviors everyone can agree are crimes? I'd rather not let the word "sin" into this one, because it's society trying to protect itself I'm after.

Thanks,
Steve
8)


February 8, 2010 05:21 AM Forum: Home Observatories

ExploraDome progress

Posted By Steve Hollenbach

Hi All,
I was able to do a little work on the dome yesterday before kickoff. The ABS track is now bolted to the underside of the dome. There are four sections that don't fit hand-in-glove, but are not difficult to install.

The hardware supplied boarders on too short, so off to Ace I went. It seems like the nice people at ExploraDome also shop at Ace Hardware, because they had the extact sizes and types of stainless steel screws and bolts necessary. I used some extra screws to be sure of two things. First that the track sat as flat as possible on the rather rounded inner edge it seats onto, and second to make sure the number and spacing of the screws would not be coincidental to the number and spacing of wheels. I used seven for each of the four sections.

I had intended to increase the number of wheels but ten ought to do. These should be installed on the ring prior to installing the ring on the building. I did the opposite to ensure my out-of-round ring could be corrected. It's within an 1/8th inch of a perfect circle. Easily within specs, and also level. That's inportant too. The vertical wheels are easy to install and there was enough hardware. The horizontal wheels were missing a few bolts. (Ace was the place)

Those keep the track of the dome, and so the dome centered in its rotation. The only problem I'll have is their method of installing these with through-bolts and nuts won't work if you've already installed the big ring on the building. OK, I used two layers of nine-ply plywood to rest the ring on, so I'll use self tapping screws to hold down the brackets those wheels ride on.

Another problem with those wheels is once the dome is installed, there's no way to adjust them without lifting the dome off again. Certainly not a single handed job. I don't intent to correct that problem, unless some adjustment seems necessary. If so, a hammer and drift pin can knock them towards the outside. The dome might have to be lifted to adjust them to the inside. It might be possible to invent a hook that can pull them with enough force to overcome the friction of the screws.

There's a three day weekend coming up, so...
More to follow.
Thanks,
Steve
8)