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Post by Ron Walker on Apr 21, 2023 11:40:17 GMT -7
Posted by: Ron Walker May 30 2007, 12:11 PM QUOTE(charles jones @ May 30 2007, 12:06 AM) * Hi Ron-
I don't think foam core would work since it is made from three laminated pieces. The idea of lamination like that is to keep something rigid. Thus, bending the material into the dome shape would tend to crack it, don't you think?
I did later try to make a dome from a material called Filon. I don't believe it is available any longer. Filon was flat sheets of fibre glass. The problem was that it was made farely thin. It proved to be far to flimsy , making it possible to cave in when you pushed on the dome. It would have needed ribbed supports. If a ready made fibre glass sheet were available today (thicker-say, 1/8" to 3/16"), it would be the perfect material to use. Maybe it is. Of course, it would be far more expensive than Masonite--but more durable.
I realize now that you must have already completed your fabric dome as I didn't get into the forum into yesterday. How is that working out?
Your other question:
I have posted photos of my planetariums constructed in 1960 - 1962. That's when I built the dome. I was 18 - 20 years old. In 1961, still in college, I seriously considered forming a company and putting a planetarium on the market. I moved on to other things.
However, because I travel a lot, I still try to visit planetariums in different parts of the world when there is time. And, yes, now that I am 65, the bug has hit me. If I don't build another projector, I know I will refurbish the little classroom projector, build another dome, and give a show or two.
By the way, check out the Peerless Planetarium pic in the Rare Planetarium topic. I'll have to share several odd Japanese projectors and several custom built projectors by local magic societies in the 50's and 60's with you guys.
But since I had very little contact with Planetarium People from about 1965 to a few years ago, I need to catch up. For example, I have a number of questions about the A3P and it's planet projectors, although I've studied the Spitz patents on these.
I know a little about the A2 Spitz having worked with the projector when I was at UCLA. I might remember something about it ...or are you the one that was asking?
Thanks for your interest -
Charles (Chuck) Jones
I have used a lot of faom core as large reflectors for soft lighting for photography. I have flexed (bent) it (4X8 sheet) to as much as 90* without any folding or cracking. That is why I thought it would work. Actually I'm thinking of using it for a larger 24ft dome with a support structure behind it made of plastic water pipe. It probably would not hold up to very many builds and tear downs and would not be very good as a portable solution.
The full size fabric dome is still in construction. Between business requirements and other family problems, fun things have had to take a back seat so to speak. However, it will happen and I will give a complete report on it when finished.
Your life story sounds a lot like mine. I'll not rehash it here, as it appears elsewhere on these pages, but it is interesting that I built my first planetariums in high school in 1963 and 4. Then business and family took all of my time and only about a year ago caught the bug again.
Can't wait to hear about and see pictures of anything concerning planetaria.
I'm going to get more of a A3P in the next couple of months and will be completely rebuilding the planet cages. Virtually everything I know of this machine has been deduced by careful study of pictures. I understand a lot of it (I think) but will have a much better understanding when I'm able to rebuild the various components. Any questions, please ask, and we'll try and answer them accurately.
I was interested in how the various parts of the A-2 functioned so we could help Gare get all of his projector up and functioning properly. Any and all information on any planetarium equipment will be much appreciated by many of us on these pages. Never think anything would not be appreciated.
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Post by Ron Walker on Apr 21, 2023 11:40:53 GMT -7
Posted by: charles jones May 30 2007, 12:36 PM Hi Ron - You might be right about foam core in larger sheets.
I always thought a lightweight dome (like this) would work suspended in a framework of geodesic design. Interesting, I saw a children's play gym at Costco that was a gesdesic dome made from tubular steel. The little dome was about 10' in diam.
I probably can help with some questions about the A-1 or A-2 as I remember something about. Ask.
Regarding the A3P, I have a copy of the Spitz patent on this detailing the planet projectors. They indicate that an second rod can be used to tilt the mirrors as the planet moves over or under the ecliptic. (Remember the planet orbits are inclined one way or another to the ecliptic). In looking at photos of the A3P, this doesn't appear to be the case. What do you think?
Do you want a copy of the Spitz patent?
I uploaded all the info and photos on my projectors as a separate topic. Did you get a chance to see it?
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Post by Ron Walker on Apr 21, 2023 11:41:13 GMT -7
Posted by: Ron Walker May 30 2007, 02:07 PM QUOTE(charles jones @ May 30 2007, 12:36 PM) * Hi Ron - You might be right about foam core in larger sheets.
I always thought a lightweight dome (like this) would work suspended in a framework of geodesic design. Interesting, I saw a children's play gym at Costco that was a gesdesic dome made from tubular steel. The little dome was about 10' in diam.
I probably can help with some questions about the A-1 or A-2 as I remember something about. Ask.
Regarding the A3P, I have a copy of the Spitz patent on this detailing the planet projectors. They indicate that an second rod can be used to tilt the mirrors as the planet moves over or under the ecliptic. (Remember the planet orbits are inclined one way or another to the ecliptic). In looking at photos of the A3P, this doesn't appear to be the case. What do you think?
Do you want a copy of the Spitz patent?
I uploaded all the info and photos on my projectors as a separate topic. Did you get a chance to see it?
As I understand it, each of the rods that drive the small mirrors that reflect the planet image out onto the dome is really a rod within a rod. They call it a "hypodermic". It is designed in such a way that vertical movement of this interior rod will "tilt" the mirror back and forth thus changing the position above and below the ecliptic. This vertical motion is controlled by an "analog" of the planet with a "wedge" that represents the inclination of the orbit. The outer guide rod may or may not rotate with the mirror as it directs the light along the ecliptic. This could all be directed by the interior rod.
The diagram below shows how this is set up to direct the planet projection to the proper place and then the second picture shows an actual analog in which you can easily see the represented planet position with the inclined wedge to represent the orbit of the planet. When I get this part of the projector I will do a very detailed report on how it exactly works with pictures.
Perhaps Owen, who has one of these machines, could tell us if the outer rod rotates with the mirror or not?
I would love to get a copy of the Spitz patent.
Your projectors are beautiful! More comments will follow at that thread.
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Post by Ron Walker on Apr 21, 2023 11:41:34 GMT -7
Posted by: charles jones May 30 2007, 04:59 PM Hi Ron -
Thanks for the diagram and explanation and, yes, as I recall the patent did describe it somewhat like this. Trouble with patent drawings, they don't really explain construction details, only the theory of the invention.
The patent also mentions something about a special mirror can be used (somewhat like a prism + mirror) so two projected images can be used to prevent the planet image from being obstructed by the planet cage. Do you think this is used?
I should email Owen.
Charles
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Post by Ron Walker on Apr 21, 2023 11:41:57 GMT -7
Posted by: Ron Walker May 31 2007, 09:12 AM QUOTE(charles jones @ May 30 2007, 04:59 PM) * Hi Ron -
Thanks for the diagram and explanation and, yes, as I recall the patent did describe it somewhat like this. Trouble with patent drawings, they don't really explain construction details, only the theory of the invention.
The patent also mentions something about a special mirror can be used (somewhat like a prism + mirror) so two projected images can be used to prevent the planet image from being obstructed by the planet cage. Do you think this is used?
I should email Owen.
Charles
This is the first I've ever heard about any attempt of Spitz planning or using a double projection to prevent the planet image from being obstructed by the planet cage. We know that Zeiss used two projectors for each planet so that this was not a problem. The dome, however, is over 30 feet away so there was little problem. With the A3P, the projector is designed for use with a dome as little as 12 feet away and this could be a problem. Like other projectors in this class, I'm guessing that the support structure of the planet cage is designed with very thin supports so that the image is not totally blocked but just dims down a bit as the light beam goes by. I have never seen one in operation but I guess no one ever complained about it.
The fact that this problem is addressed in the patent makes me wonder just how bad a problem this is. A simple 1/2 silvered mirror/prism with an additional mirror would be required to split the light beam into two beams for projecting onto the dome. Alignment problems probably sealed the fate of this particular part. Also it would have had to attached onto the rotating mirror after the light beam is reflected from the movable mirror which could add substantial weight and cause unacceptable vibration.
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Post by Ron Walker on Apr 21, 2023 11:42:27 GMT -7
Posted by: Ron Walker Jul 12 2007, 04:17 PM For those of you that thought the large dome project had gone away, fear not. With just a little arm twisting (a new stove) I convinced my better half to continue helping me with the construction.
Here is a picture of the last gore being cut from material. Because of the size and weight of this thing, I'm thinking of having the gores divided up into four sections so they can be easily set up and taken down. If everything goes as planned, I should have this first experimental large dome up and operational by the weekend of the 21st. Wish me luck.
I should be starting on the frame structure tomorrow. What joy!!!
Now I must wire in the new stove. wink.gif
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Post by Ron Walker on Apr 21, 2023 11:42:47 GMT -7
Posted by: Ron Walker Oct 4 2007, 09:57 AM QUOTE(mrgare5050 @ Oct 3 2007, 06:13 PM) * wow i want one of those! hows your dome coming?
Looks like I will be getting Ken's portable blow up dome. This I plan to use with the E-5 in an outreach program with my astronomy group as well as outreach to the local library and schools.
My larger fabric dome is in four sections for easier handling. All I need to finish it is build the support framework and put it together.
Rebuilding the A3P has been taking all of my spare time right now. I will probably take some time to do some final tweaks on the E-5 so I will have no excuse not to face the public.
The problem is there is just not enough of me to go around and because of "Walker Ranch North" funds to build an addition for a permanent location have been put on hold for a bit.
Talk about that mirror is in the sections that talk about mirrors and the like. I do need to break this forum up into at least some basic sections as it is beginning to get out of hand.
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Post by Ron Walker on Apr 21, 2023 11:43:05 GMT -7
Posted by: mrgare5050 Oct 5 2007, 04:45 AM
Looks like I will be getting Ken's portable blow up dome. This I plan to use with the E-5 in an outreach program with my astronomy group as well as outreach to the local library and schools.
well you have to do what CAN BE DONE, better to do something than dream another year!
My larger fabric dome is in four sections for easier handling. All I need to finish it is build the support framework and put it together.
dome pergatory goes on .. i went through that phase of buying white duct tape for 2 months ...
Rebuilding the A3P has been taking all of my spare time right now. I will probably take some time to do some final tweaks on the E-5 so I will have no excuse not to face the public.
thats right, then you'll be where i am, wondering 'i built it, but they aint came yet'.... now what...
The problem is there is just not enough of me to go around and because of "Walker Ranch North" funds to build an addition for a permanent location have been put on hold for a bit.
im already thinking bigger - i cannot BELIEVE it... i drove by the pyramid downtown yesterday, kris mccalls 60 footer going up...
Talk about that mirror is in the sections that talk about mirrors and the like. I do need to break this forum up into at least some basic sections as it is beginning to get out of hand.
ah success breeds its own problems smile.gif gare
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Post by Ron Walker on Apr 21, 2023 11:43:36 GMT -7
Posted by: Ron Walker Oct 5 2007, 08:57 AM QUOTE(mrgare5050 @ Oct 5 2007, 04:45 AM) * Looks like I will be getting Ken's portable blow up dome. This I plan to use with the E-5 in an outreach program with my astronomy group as well as outreach to the local library and schools.
well you have to do what CAN BE DONE, better to do something than dream another year!
My larger fabric dome is in four sections for easier handling. All I need to finish it is build the support framework and put it together.
dome pergatory goes on .. i went through that phase of buying white duct tape for 2 months ...
Rebuilding the A3P has been taking all of my spare time right now. I will probably take some time to do some final tweaks on the E-5 so I will have no excuse not to face the public.
thats right, then you'll be where i am, wondering 'i built it, but they aint came yet'.... now what...
The problem is there is just not enough of me to go around and because of "Walker Ranch North" funds to build an addition for a permanent location have been put on hold for a bit.
im already thinking bigger - i cannot BELIEVE it... i drove by the pyramid downtown yesterday, kris mccalls 60 footer going up...
Talk about that mirror is in the sections that talk about mirrors and the like. I do need to break this forum up into at least some basic sections as it is beginning to get out of hand.
ah success breeds its own problems smile.gif gare
I can't imagine having control of a 60 foot dome. huh.gif That means a 35 foot tall room at the very least. It will be fun to just have anything up and working. That is part of the problem with building a permanent dome of large size. I'm thinking of a spring line of three feet (I really like the idea of a low horizon so your not looking out from a hole in the ground) and would like a dome of 24 feet. That means a ceiling height of 15 feet. About the only place I can add on to is the front of the house which has a nine foot ceiling height. Putting in cathedral trusses would probably gain me another foot at the center of the room giving me ten feet. That means I would need to dig down five feet into the ground to make this whole thing work. In the mean time I will set up my 18 foot fabric dome on my work stage which has 12 foot ceilings which will still allow for a three foot spring line. And that's just the planetarium project! blink.gif
Must do some "work" work today.
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Post by Ron Walker on Apr 21, 2023 11:44:08 GMT -7
Posted by: mrgare5050 Oct 6 2007, 04:43 AM
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Post by Ron Walker on Apr 21, 2023 11:44:43 GMT -7
Posted by: Ron Walker Oct 6 2007, 10:56 AM
QUOTE(Ron Walker @ Oct 5 2007, 03:57 PM) * I can't imagine having control of a 60 foot dome. huh.gif That means a 35 foot tall room at the very least. It will be fun to just have anything up and working. That is part of the problem with building a permanent dome of large size. I'm thinking of a spring line of three feet (I really like the idea of a low horizon so your not looking out from a hole in the ground) and would like a dome of 24 feet. That means a ceiling height of 15 feet. About the only place I can add on to is the front of the house which has a nine foot ceiling height. Putting in cathedral trusses would probably gain me another foot at the center of the room giving me ten feet. That means I would need to dig down five feet into the ground to make this whole thing work. In the mean time I will set up my 18 foot fabric dome on my work stage which has 12 foot ceilings which will still allow for a three foot spring line. And that's just the planetarium project! blink.gif
TALL is definitely the limiting factor here is well, though the thought of renting a bucket truck has always intrigued me, i could use it to repair my barn roof at the same time! This is why though the pyramid design has intrigued me as a simple (straight edges with only a few interface points) possibly doable model, with metal roofing on it. I suppose these posts belong in DESIGNING THE DOME or some such subject! gare
Not exactly sure if a pyramid would be the best bet for making a planetarium from scratch unless I had a lot of money to spend. One thing is height and the zoning problems with it. If there were no zoning limitations I think I would build a geodesic dome to house the projection dome inside. It is extremely strong and self supporting. Can be built with one or two people and does not need a tall point which contains useless space.
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Post by Ron Walker on Apr 21, 2023 11:52:32 GMT -7
Posted by: Ron Walker Oct 6 2007, 10:56 AM
QUOTE(Ron Walker @ Oct 5 2007, 03:57 PM) * I can't imagine having control of a 60 foot dome. huh.gif That means a 35 foot tall room at the very least. It will be fun to just have anything up and working. That is part of the problem with building a permanent dome of large size. I'm thinking of a spring line of three feet (I really like the idea of a low horizon so your not looking out from a hole in the ground) and would like a dome of 24 feet. That means a ceiling height of 15 feet. About the only place I can add on to is the front of the house which has a nine foot ceiling height. Putting in cathedral trusses would probably gain me another foot at the center of the room giving me ten feet. That means I would need to dig down five feet into the ground to make this whole thing work. In the mean time I will set up my 18 foot fabric dome on my work stage which has 12 foot ceilings which will still allow for a three foot spring line. And that's just the planetarium project! blink.gif
TALL is definitely the limiting factor here is well, though the thought of renting a bucket truck has always intrigued me, i could use it to repair my barn roof at the same time! This is why though the pyramid design has intrigued me as a simple (straight edges with only a few interface points) possibly doable model, with metal roofing on it. I suppose these posts belong in DESIGNING THE DOME or some such subject! gare
Not exactly sure if a pyramid would be the best bet for making a planetarium from scratch unless I had a lot of money to spend. One thing is height and the zoning problems with it. If there were no zoning limitations I think I would build a geodesic dome to house the projection dome inside. It is extremely strong and self supporting. Can be built with one or two people and does not need a tall point which contains useless space.
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Post by Ron Walker on Apr 21, 2023 11:53:06 GMT -7
Posted by: Owen Phairis Oct 6 2007, 04:44 PM Here is a shot of my expensive portable dome. Owen Spitz A1, A3P, Nova III, GOTO S-2 www.pictorialism.com
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Post by Ron Walker on Apr 21, 2023 11:53:27 GMT -7
Posted by: Ron Walker Oct 7 2007, 09:24 AM QUOTE(Owen Phairis @ Oct 6 2007, 04:44 PM) * Here is a shot of my expensive portable dome. Owen Spitz A1, A3P, Nova III, GOTO S-2 www.pictorialism.comIt looks like there is an extra layer on the top. Is that to keep light out? Also, does all the set up time ever get you down and wonder if it is worth the trouble? That is the thing that I'm most worried about myself. Not only the time and trouble of getting the whole thing set up, but what kind of response will I get. I can't handle the negative kind for long
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Post by Ron Walker on Apr 21, 2023 11:53:48 GMT -7
Posted by: Owen Phairis Oct 7 2007, 11:25 AM QUOTE(Ron Walker @ Oct 7 2007, 09:24 AM) * It looks like there is an extra layer on the top. Is that to keep light out? Also, does all the set up time ever get you down and wonder if it is worth the trouble? That is the thing that I'm most worried about myself. Not only the time and trouble of getting the whole thing set up, but what kind of response will I get. I can't handle the negative kind for long Hi Ron, Yes, even though they said it was light proof, needless to say it was not. sad.gif Well yes, it was a little troublesome not getting the attendance I hoped for. However, the few people that did take the time to see the show loved it! biggrin.gif I think we all need to remember that 'educational show' does not envoke the same emotional response that 'Disneyland' does. I guess that is why I am taking a little different direction from most of you. I am now thinking more in terms of a small permanent science museum specializing in planetarium projectors and the space and physical sciences. It will be interesting to see what path the museum leads me. Allthough it appears to be several years away, I hope to start on the publicity campaign this winter to see if there is any interest. Any ideas? Ron, Are you shooting any HD TV? I was thinking of buying the Sony HDR V1U..... Owen www.pictorialism.comSpitz A1, A3P, Nova III, GOTO s-2
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