Folks

My ExploraDome will be here the week of April 9th. I intend to post a blog on my website for all construction phases and issues and successes. My wife has given me her blessing and I did not even have to ask. "If, you trip one time lugging "The Beast" outside, the repair and freight would exceed the cost of a shed!". Been to City Hall and all is well with those folk. "No Problem!" was their reply.

Here is the link http://www.jondokken.com/AstroAsylum/AstroBlog.htm

It will probably be late April before too much happens. Check in from time to time to see how the construction is coming.

Jon ...


ps: Here is a pictur eof one from PolyDome/Exploradome's website of someone in the west' version. Mine will be patterned after this style.

Welcome to the OC!

Please feel free to post images here with your progress (Same thread).

You are also welcome to have your own Image Gallery, as well as a Blog on this site as well.

Looking forward to seeing your progress.

Welcome Jon to OC

When you got the "no problem" from City Hall do you have any plans on paper for them to see? Did they just call it a "shed"? I'm asking as I'm just about ready to go for my "OK" and not at all sure how to treat it or what to call it. Once I get past that it will "all be down hill".

Also, if you have the time, post some of your pictures here, they will be appreciated.

I also like the look of the picture you put up. Have no idea of who that is but look very nice. I think I'm going to go with a square base however as the corners are good places for that extra storage that is always needed.

Looks like a similar observatory with an ED in Canada I believe... Did a square roof, with octagon building.. (Cedar walls inside!)...

In my case, City Hall mentions a certain height, a certain total sqr footage. I fell within both. So, they do not care. That simple ...

But, I did mention that the whole thing will be anchored to sustain 120mph winds.

Jon ...

Here is the link to the dome I am going to fashion mine after ...

http://www.exploradome.us/Explora_Dome_Pho...?CustomerID=179

Jon ...

Jon:
You're in St. Paul! You might be one of the closest to Litchfield! You could drive a pickup down there and pick it up in person!
Dave Beckstrom, our admin here on OC, is in Andover, so he's been our "on site" representative at the manufacturer. Now we have 2 guys who can go to Litchfield and pester Dan!
That's priceless!
Rich

Jon is about 30 miles from me.

Yes, I live on the east side of The Metro. Did the math of going out and picking it up and, at 170 round trip, plus trailer hassels, and getting stopped by one of Minnesota's finest for an 8' load? $100 for delivery to my front yard was a good deal. Dave is a bit closer than I. I have a deck against the house to build, another platform for a screen porch in the trees and also my AstroAsylum. I think I will do the Asylum first ... :-O

Jon ...

Let us all remember to enjoy our toys and, the beauty above and within, each of us ...

+++

Big Dog's Astro Asylum
Woodbury Minnesota

LX200KGT 12" KindaGetsThere Scope

The ExploraDome came yesterday.

Here's some pix/comments

http://www.jondokken.com/AstroAsylum/AstroBlog.htm

Will write more in a day or two.

Jon ...

Jon,

Looks good! I bet you are excited! Hey, if you have any desire to see an explora-dome observatory before you start your build, you are more than welcome to stop out.

Dave

Dave

Expect a call in the next 2-3 weeks! Would be fun to see it.

I pretty much have the construction (major) details rolling around in my head. I am probably going to make my own ring for the dome which will ride on the wheels. But, will have to see how their stiffeners might do for that as well.

Thanks

Jon ...

Just wanted to bring folks up to date.

Not much new as I am waiting for my Mitty wedge. Ordered it in January, was told March delivery, and now it is being promised in early June. Need that to calculate wall height and also pier placement within the dome itself.

But, I have added to The Blog ... http://www.jondokken.com/AstroAsylum/AstroBlog.htm

Was out tonight and I can ---not--- wait to get The Beast housed in something permanent. Metro skies and all. Btw, last week I was out til 3:00am. Once the neighbors (white) lights were out, I saw things I have never seen before in my backyard site. Encouraging, it was.

And when I start the actual construction, there will be plenty of pix and details. Promise ...

Jon ...

Let us all remember to enjoy our toys and, the beauty above and within, each of us ...

Thanks for the update Jon. It's nice that your backyard shows promise despite metro skies and your neighbors light.
Your neighbor will probably notice you are building an observatory and maybe that will give you a chance to discuss the lighting problem with him.
Looking forward to the construction details and pics!

The neighbor's lights are not nor will be a problem. I intend to keep the lower flap "up" all the time and that should eliminate any light issues. PLus, withmy house and trees etc, any observing near a horizon will not happen at this location. It was just the other night, about 11:30 or so, all their lights were off and that really improved the seeing dramatically w/o their white light ...

Jon ...

Folks

In a few days, I will -finally- start my AstroAsylum construction. Have had an ED for two months and, will probably go ahead without having the Mitty wedge. I may not get heavy into photography and, Alt Az may be good enough for starters.

So, I have created an image of my back yard. North is straight up. My house faces pretty much NW. The red circles are white light - being two streetlights, my neighbors upstairs hallway light and the neighbor in the back has a half dozen floods for his back yard. These are not problems after about 10:30 at night. The streetlights are also not an issue for me. And the ED will block most of this for me.

St Paul and Minneapolis Grandeure is pretty much due west of my home. It does glow, indeed. My living on the east edge of where 3 1/2 million people call home.

Three circles mark where it would be best to place the Asylum. All the trees are pretty much about 25-30ft tall from the ground. There is an apron around the pool that is about five feet off the ground. Green and Yellow would be on that apron.

(Yellow) Good spot for ecliptic to the west, largely over my neighbors house. And then NW between my house and theirs. One can see Venus from here. Nothing any other place. Lousy (trees) for the ecliptic from the west to the east. Not bad for the eastern sky above 40 degrees and of course all points north. My neighbor to the west would see the dome of the Asylum from their pool - which they use alot. Folks walking past on the path to the west would briefly see the dome of the Asylum - and then, only of they knew where to look (over my neighbors fence/pool).

(Green) Great for the ecliptic from about south thru southwest. Nonexistant before and after that. Venus and Mercury are always behind the houses. Good view to north and also pretty good to the east. Most observing would be over trees, not houses. The asylum is largely out of sight from all the immediate neighbors and the path.

(Blue) Tonight I walked about back there and spotted this location. The ecliptic can be seen in almost its entireity. At 10:30 Minn time, the moon, Jupiter, Saturn and Venus - all, very nice indeed. Beyond due south to the SE, the trees block the ecliptic. North is easily visible, the Minneapolis/St Paul Metro Glowlamps are largely behind the houses. There is a tall tree halfway between the blue and green spots that would partially block a small patch of sky to the SE. (The satelite image being a bit dated.) After 40 degrees up from the ground, clear sailing. Folks walking past on the path to the west would only see the dome of the Asylum.

All this, is of course a compromise. I envy those in Kansas, on a farm with Toto at their side. Or No Dakota for that matter. :-) But, the metro is the metro and this is where my mortgage resides right now.

I know, in the winter, the ecliptic will sink lower. Heat from houses will foil some things, but I am searching for the best compromise I can get.

Folks, what do you think?

Jon ...

Let us all remember to enjoy our toys and, the beauty above and within, each of us ...

+++

Big Dog's Astro Asylum
Woodbury Minnesota

LX200KGT 12" KindaGetsThere Scope

'Twere me, I'd probably go with the blue spot. It has the best sky access.
Let the dome block the lights and have at it! Put the thing on a deck with DeckBloks (or whatever it's called) so you could move it if it proved to be less than adequate...
Rich

Go with the blue and cut down the tall tree!

I vote for the blue as well.

I like the blue spot. I recently had to go through such a debate. The blue spot seems to be the best.

Blue won out - both here and on Yahoo LX200GPS group.

I have had 2-3 nights back there and it will be fine.

Thanks

Jon ...

Hi folks,

Well, the Mitty should be on a truck somewhere in the USA and headed towards Minnesota. So, my Astro Asylum will be started shortly.

I also decided to return to the "Green" spot for the location. In the end, after using both, this one would give me a better view where the skies will be the darkest.

As regards the wheel kit and ring etc. I am making the ring myself, but will probably buy wheels from Dan. My ring will be a bit different from all the others I have seen. After I firm up some dimensions, I am ready to fetch some decent 3/4 ply, and get started. All other's ring construction attempt to make something on the dome fit something on the base. So, mine will be a seperate part completely, which will fasten to the dome and the base, but, will be quite precise in the tolerances hance, the actual rolling around the track will (should) be far more uniform.

Think of a Lazy Susan. With a saw, go around the actual track inside and out, bolt it into the dome and onto the base and there it is. I am also planning to retain the dome from vblowing off from the inside, not the outside. Stay tuned on that.

I will also post complete construction articles here. Pix and all. As well as my website http://www.JonDokken.com

The following post will have what has been posted already.

A few more things where mine will be a bit different. Octagon shaped. Wooden pier/column. Easy to dis-assemble. And, like a Pod dome, a couple panels will have some small bays for computer, books etc.

So, stay tuned ... In a few days, things will be happening really fast.

Jon ...

Folks, finally, I will have my planning and plans are settled. I may get a chance to start construction today Sept 1st. A nice date to begin - finally.

Being promised a wedge delivery back in January for February/March, I had my dome here in April. But, no wedge until 2-3 weeks ago. So, finally, ready to go.

I have the older model ED and will have to paint/plaster the inside. Like Pete stated, it will help with the dark adaptation of my tired eyes.

The base will be a small deck. 2x8's in the floor, cedar deck lumber, roughly an eight foot span, square. Simple, not fancy.

The column/pier/post will be of exterior plywood. Either square - hex or octagonal. Square being easiest to construct. At least two 3/4" layers glued if not three. I am far more concerned of the frost/ground settling than I am of the post warping/bending. It will be set 3-4 feet in the ground to get below frost and I may have it so the top of the column can be unbolted from the bottom portion. I want it to be so when I move to a warmer location and take it with me, sell it, or it burns down from a lightning strike, there will be no sign of it except for some dead grass. No cement to mix, no pad/post to break up.

The Asylum will be octagonal, wood. I will make it with foam cored walls and 4x4 cedar corner verticals for the walls to lock into. Having eight sides, I am planning three to have small bays. Keeping the water out, and, taking longer for construction might be an issue with bays. Center to center distance on an outside flat will be 3' 0". Exterior will be cedar siding and the interior will probably end up being either 1/8" masonite or some light colored paneling. Varnished to look nice and easy to clean. The sandwich will be glued with yellow carpenters glue. Edges will be a mixture of 2x2 and 2x4's. The bottom edge will have a small inside lip to aid in fastening the walls to the deck.

The Ring, yes, The Ring. In the simplest of terms, it will be three major pieces. Plywood, glued and screwed. The upper ring will be three layers, and the outside diameter will conform to the inside diameter of The Dome lip. The inside diameter of the upper ring will be slightly smaller than the bottom ring inside diameter. Maybe two inches.

The middle ring will be 3/4" ply with 1/8-1/4" masonite top and bottom. Glued, and screwed. The ring will have 10-12 slots for the wheels to fit into. Holes for a 1/4" axle will be drilled and retain the wheels. The outside diameter will be the same as the bottom ring. The inside diameter the same as the upper ring.

The bottom ring outside diameter will be 1-2" smaller than the upper ring outside diameter. The inside diameter will be the same as across the inside flats of the octagon. Hence, -maximum- room from the dome on down to the floor. It will be two layers, glued and screwed, and will be bolted to the tops of the walls.

The upper and lower rings will have a radiused groove routed around the face of the center of the ring for the wheels to ride around in. Whatever depth and width is needed for a comfy fit for the wheels.

The inside offset between upper, middle and lower rings will be for some "L" shaped bolts. The "L" will be above the upper ring and the lower portion will be bolted into the lower ring. This prevents the whole thing from flying off.

With this type of ring construction, I retain maximum room on the inside, the ply will force the dome to be round, there will not be any unnecessary pieces as regards retention. And, the rotation should be ultra smooth. Also, if I want automation, that too, should be easy to install.

There has been alotta chatter of bulletproof doors lately. Folks, if a Bad Guy wants to get into my Asylum, they will. So my door will be a simple affair of a sandwiched cedar/masonite with crossbuck accents and cedar trim. I believe, if someone wants to get in bad enough, they will bring a key hole saw, make a hole in the dome large enough and crawl in easily. Two minutes should do it. So why worry of doors made of 2x6's etc? Not me.

The pier will be offset so the axis of the scope will coincide with the vertical axis of the dome.

Stay Tuned, pix to follow as I progress ...

Jon ...

Let us all remember to enjoy our toys and, the beauty above and within, each of us ...

+++

Big Dog's Asylum
Woodbury Minnesota

LX200KGT 12" KindaGetsThere Scope

Jon:
That's the "Git 'er done!" spirit! Looks like you've thought it all out thoroughly, there's nothin to it but to do it.
Don't forget to take lots of pictures and post 'em!
Winter's coming!
Rich

Heavy doors and locks are designed to keep honest people honest. Your right in that if someone really wants in, they will get in.

Question. How do I insert pictures alongside my text?

Thanks

Jon ...

Latest entry into my blog with pix of

Wheels

How To Calculate the Pier Offset

http://www.jondokken.com/AstroAsylum/AstroBlog.htm

Jon ...

Let us all remember to enjoy our toys and, the beauty above and within, each of us ...

+++

Big Dog's Asylum
Woodbury Minnesota

LX200KGT 12" KindaGetsThere Scope

For posting a picture go to:

http://www.observatorycentral.com/index.php?showtopic=332

for a complete explanation.

Just remember that there is 100K maximum for any one post. I have found that if you take your picture into photoshop and limit the width to 500 pixels and then save it as a JPEG at a resolution of "2" then your picture will take up about 30K or so. This allows you to mount three pictures in one posting. Hope this helps.

(Here are the Wheels I went with for the Rotation Ring I will make)

Wheels

Exploradome sells a kit for dome rotation. I thought a different design might be fun to try.

But first, you need wheels. I wanted a urethane type, with a 1/4" or 5/16" hole for the axle, and ball bearings if I could find them.

After some digging, Sport's Shops sell repair kits for inline skates and offer a variety of wheel sizes and types.

An 80mm wheel comes out to 3 1/8: and should be what I needed.

Here is a pix of what I got.

Click to view attachment

I thought you might like the pretty printing. Others were much better but cost more. Note the two ballbearings that are included. Very smooth, they are.

Click to view attachment

About 7/8" thick which was great.

Click to view attachment

And, 8 of them are $40. $5 each. I bought 16 total and there will be a wheel every 22 1/2 degrees. Wanna save a bit more? Buy them on the internet. "Dick's" were the cheapest. BUt I wanted to see and feel and measure.

Btw, a 1/4" bolt/shaft fits perfectly in the 8mm hole of the bearing.

Here are the current thoughts of how the ring will look in cross section.

Click to view attachment

Turquoise - Top ring attached to the dome
Yellow - Middle ring that holds the wheels.
Salmon - Bottom ring attached to the walls of the Asylum.

The wheel is pink. An approximate location of each corner of the octagonal walls is in red (Corner Post) and an approx location of the walls themselves is in green. Being octagonal, the wall between the posts will measure less than to the post.

I am going to build the posts and walls before I finalize these measurements.

But, doing things this way, a number of issues go away and benefits arise.

The dome will be alot more round than using the plastic rings etc.

This arrangement should operate much more smoothly than the standard method.

It might be cheaper than buying the mfgr's version.

I will have more wheels to distribute the weight. I hope this allows the dome to be pushed from one place to the other very easily.

A problem I am facing will be to keep the ring segments, after being glued together, round and concentric, one to another. Especially, the groove where the wheels will ride on both the upper and lower irings..

(Here is the method I used to calculate the offset of the Pier within my Asylum)

Axis Calcs

I wanted to locate the vertical axis of the OTA in line with the vertical center of the dome. These calcs are by and large unique for the telescope and wedge used.

(Yes, another Meade 12" LX200KGT setting on a Mitty wedge will be the same.)

So I set up The Beast and thought you may enjoy how I did these things.

Click to view attachment

These three pix are from the top looking down at the wedge base. I like to align using a cheap 6" level and align paralllel to all three legs. One at a time.

This has become a very easy and quick way of achieving a practical level.

Above is the first leg.

Click to view attachment

The second.

Click to view attachment

The third.

Now, we know the wedge base is level and now we need to get an approximate tilt of the wedge based on our latitude.

Click to view attachment

First, lock the RA down at zero so the tube is kinda vertical.

Click to view attachment

(The other night, I made certain the angle-o-meter is pretty close to being zero when the scope is horizontal and 90 degrees when it is pointed straight up.)

My location is 45 degrees so I set the angle to that.

Click to view attachment

Then, using the wedge tilt adjustment, get the OTA so it is straight up.

I carefully put my level on the edge of the scope. And was careful not to knock it down onto the corrector plate.

Click to view attachment

Keep manually adjusting the wedge until the tube is level.

Will this result in the OTA being absolutely vertical? Probably not.

But it is good enough.

(Cont'd on Next Page)

(Cont'd)


Click to view attachment

So here is what we have now.

See the little red plug courtesy of Peterson Engineering? That will be the easiect way for us to find a way to hang a string from the center of the OTA. It even has a tiny dimple where the center is.

I removed the diagonal and plopped the plug in.

Click to view attachment

I poked a hole in the center of the plug and knotted a string and pulled it thru. Put a small socket on the bottom, suspended by a match so the tilt of the socket would nt be too bad for vertical.

A Poor Mans plumb bob.

Click to view attachment

We want to find the center of the knob, which is the center of the supporting tripod (or pier) and then, measure to our string which is the center of the OTA.

Finding the center of bolts or knobs can be a bit tricky. Here is a shortcut that will work fine.

We will measure from both the front and back of the knob by rotating it just a bit.

Above is one measure, below, another.

Click to view attachment

Click to view attachment

From the front.

Click to view attachment

And the back.

(Cont'd)

(Cont'd)

Click to view attachment

Our front side measurement.

Click to view attachment

About 5 13/16".

Click to view attachment

And from the back. About 8 5/16".

Add the two together.

13 18/16th

Which gives us 14 2/16ths

Or 14 1/8"

Divide by 2 and our offset will be

7 1/16"

Or, just plain 7" will be good enough.

We will place the supporting pier/column 7" off center within the dome structure. The hole in the floor also has to be offset this amount as well.



Click to view attachment

The inside of the plug.

Click to view attachment

The socket and matchstick.

Click to view attachment

The underside.

(End)

Great tip for anyone looking to find their offset!

MUCH easier than the way I did it...

Here are the current thoughts of how the ring will look in cross section.

Click to view attachment



Have you given any thoughts as to what will happen when it gets cold and the dome shrinks. Looks to me like you might generate quite a bit of lateral loading with this setup.

I was gonna post how much I like the idea of having the wheels on an inner ring and all, but Loco's right, when the dome contracts in cold weather the grooves that the wheels ride in might shift... The wheels will then try to ride up the inner or outer edge of the groove... Gotta think...
Rich

I thought of thermal expansion. Especially when the Minnesota permafrost settles in. Remember, all three rings are made of the same material. So they will shrink/expand the same. The issue comes with the dome itself. How much will that tighten up when 20 below. I am leaving at least a 1/4" gap between the upper ring and the inside lip of the dome. And, when I run screws through the whole thing, the clearance holes in the upp ply ring will be a bit sloppy to permit movement between the two as well.

In other words, I am not expecting a problem. And, besides, 2-3 layers of 3/4" plywood in a circular ring is awfully strong.

Jon ...

Let us all remember to enjoy our toys and, the beauty above and within, each of us ...

+++

Big Dog's Asylum
Woodbury Minnesota

LX200KGT 12" KindaGetsThere Scop

So if the cyan, the yellow, and the butterscotch (that's the colors that are on MY monitor ) are all 3/4 ply, then I see where you'll have no problem. Yeah, just make sure you have allowance for expansion & contraction of the polyethylene and you'll be all right. I do like the inner ring with wheels design. It's rather like a ball bearing itself!
Rich

Think of it as a Giant Lazee Susan ... And, what is intriguing for me, is it is a functional unit all by itself. Self contained, if you will. Plus, it will keep the dome nice and round at the base of it. I would wager good money, the dome shrinkage will not be a problem. If it is? I have a Plan B in my hip pocket.

Did the pix come thru for you? Or did you have to click on the links?

Jon ...

Let us all remember to enjoy our toys and, the beauty above and within, each of us ...

+++

Big Dog's Asylum
Woodbury Minnesota

LX200KGT 12" KindaGetsThere Scope

The pix are right there, nested in the text like they should be.
This is SO much more powerful than CN's way of handling images.
It really helps you tell the story.
BTW, I like the socket & match plumb bob! Works for me!
Rich