Post by Ron Walker on Apr 29, 2022 18:07:26 GMT -7
Posted by: Charlie Miller Nov 27 2012, 12:42 PM
Hi folks,
It has been a long time since I've posted. Had some tough times in the employment area (I would not advise anyone to aim for non-tenure positions in academic research!).
But anyway, I have been working on my home-built to make it better for outreach activities (did 5 such event this year). So far I've added:
1. A "pico" video projector (about the size of a cigarette case, with an LED as the light source). Good enough for bringing video content into the dome.
2. A moon projector, using the several moon-phase transparencies tHat I previously posted (I went for about a 1 degree sized moon). Basically used the old Nova III approach, but with better images. Light source: a 1W LED.
3. A Jupiter or Venus projector. Moves on the main axis, but not on any motor drive.
4. Finally, slip rings for the star bulb. This eliminates a significant drawback of twisted and broken wires. Here is a pic of the original design of the brush (a simple piece of brass). The second iteration involved soldering 6 small brass rods on a piece of brass, grinding flat areas on them, then bending them.
More pics later. My nonprofit is barely hobbling along. Part of this is my fault. I am not a businessman or salesman. A real problem these days when the confidence game seems SO important for biz promotion.
Posted by: Ron Walker Nov 28 2012, 09:12 AM
Do the brushes have any "spring" to them? The thing I found when using normal materials is that they tended to not hold contact for very long. Spring steel or an actual spring was needed to hold the brushes in place on the ring. I found that the simple contact arms from old relays worked rather well for such slow turning contacts.
Posted by: Charlie Miller Nov 28 2012, 10:52 AM
Hi, Ron,
Yeah, I agree. I'd like to use a spring steel approach, but one problem is that I've lost access to a machine shop, so forming nice parts (like the brush I made out of brass) isn't easy with my tools (or perhaps my hands).
So what I have now is WAY better than constantly ripping up wires (pretty damn crude!), but i suspect I'll need a better revision.
c.
Posted by: Charlie Miller Nov 30 2012, 07:34 AM
Projector progress, cont'd...
Here is an image of the slip ring assembly mounted to the southern disk of the star cylinder. Brush tension is maintained by the spring assembly.
This took me forever to get around to, in part b/c I no longer have access to a machine shop with donated labor.
I found (on the Internets) a way to use glossy magazine paper to create a mask transfer (using a toner-based printer). That pattern (for the rings) was then transferred to copper clad board via heat from a household iron. It worked pretty good, though I had to beef up the resist pattern with nail polish (perhaps I did not have the copper surface clean enough?) Thus the wiggliness of the rings in spots.
Early tests look good. Hope it works... Now need to build another one for the electrics south of the declination axis.
Posted by: SteveDurham Dec 1 2012, 07:00 PM
Looks PDG to me.....nice work!
Steve
Posted by: moonmagic Dec 2 2012, 05:56 PM
Looks VERY good to me! mm
Posted by: tomoarnold Nov 4 2013, 11:31 AM
QUOTE(Charlie Miller @ Nov 30 2012, 08:34 AM) *
Projector progress, cont'd...
Here is an image of the slip ring assembly mounted to the southern disk of the star cylinder. Brush tension is maintained by the spring assembly.
This took me forever to get around to, in part b/c I no longer have access to a machine shop with donated labor.
I found (on the Internets) a way to use glossy magazine paper to create a mask transfer (using a toner-based printer). That pattern (for the rings) was then transferred to copper clad board via heat from a household iron. It worked pretty good, though I had to beef up the resist pattern with nail polish (perhaps I did not have the copper surface clean enough?) Thus the wiggliness of the rings in spots.
Early tests look good. Hope it works... Now need to build another one for the electrics south of the declination axis.
Hi Charlie;
Your slip ring design is impressive! Do you have a photo of the instrument as it now stands? I would really like to too get an idea of your plans. I am in the process of building a machine with an A3 starball.
Tom
Posted by: Charlie Miller Nov 4 2013, 11:38 AM
QUOTE(tomoarnold @ Nov 4 2013, 12:31 PM) *
Hi Charlie;
Your slip ring design is impressive! Do you have a photo of the instrument as it now stands? I would really like to too get an idea of your plans. I am in the process of building a machine with an A3 starball.
Tom
Hi there.
Well, let me take a picture. I'll be setting up my projector for my last community outreach (my business plan failed rather definitively sad.gif ). I don't have an up-to-date image. An "earlier photo" (hmmm... as in an obit) is on my website at www.RediscoverScience.org... look under the "about us" tab and then the "material resources" page.
Probably a design weakness of my slip rings is the use of copper for the brushes. Yes, they are spring loaded, but I think that the use of spring metal might be a bit better. There's the phosphor alloy that is supposed to be good. But I had trouble cutting each brush into the series of parallel tines. Another possibility is to use the brush material used in the model slot-cars. But eventually, time limits all solutions or obsessive-anality!
Posted by: Charlie Miller Nov 4 2013, 11:45 AM
QUOTE(Charlie Miller @ Nov 4 2013, 12:38 PM) *
Hi there.
Well, let me take a picture. I'll be setting up my projector for my last community outreach (my business plan failed rather definitively sad.gif ). I don't have an up-to-date image. An "earlier photo" (hmmm... as in an obit) is on my website at www.RediscoverScience.org... look under the "about us" tab and then the "material resources" page.
Ah, the classic A3.... what needs to be done with it? Are you just starting with the star-ball only?
Tom... I purchased a set of A3P planet analogs... unfortunately from a sort of charlatan. They were shipped without the mirrors and most of the co-axial (rod-inside-tubing) parts are damaged. I'd consider giving them away for the cost of shipping, if you wanted to go that far. I will not say how much I paid for them (way too much). But they are just collecting dust and reminding me of a rather crappy business deal by a dealer in Florida who was reluctant to describe their condition. I'm assuming the analog computers of each are okay. But this would not be a novice project, as you'd need to also build power supplies for each, which as I recall use variable frequency supplies.
Posted by: Ron Walker Nov 4 2013, 12:56 PM
QUOTE(Charlie Miller @ Nov 4 2013, 11:45 AM) *
Tom... I purchased a set of A3P planet analogs... unfortunately from a sort of charlatan. They were shipped without the mirrors and most of the co-axial (rod-inside-tubing) parts are damaged. I'd consider giving them away for the cost of shipping, if you wanted to go that far. I will not say how much I paid for them (way too much). But they are just collecting dust and reminding me of a rather crappy business deal by a dealer in Florida who was reluctant to describe their condition. I'm assuming the analog computers of each are okay. But this would not be a novice project, as you'd need to also build power supplies for each, which as I recall use variable frequency supplies.
Or you could do a mechanical retrofit like I did. I wonder if your "crappy business dealer in Florida" is the same as mine? As for brushes, I find that the contact units from surplus large relays work quite well. They not only have the spring tension but a contact bob on the end as well.
Tom, you will never get a deal offer like that again, I'd jump on it. Though personally I think Charlie should get something for his investment.
Posted by: tomoarnold Nov 4 2013, 01:03 PM
QUOTE(Charlie Miller @ Nov 4 2013, 12:45 PM) *
Tom... I purchased a set of A3P planet analogs... unfortunately from a sort of charlatan. They were shipped without the mirrors and most of the co-axial (rod-inside-tubing) parts are damaged. I'd consider giving them away for the cost of shipping, if you wanted to go that far. I will not say how much I paid for them (way too much). But they are just collecting dust and reminding me of a rather crappy business deal by a dealer in Florida who was reluctant to describe their condition. I'm assuming the analog computers of each are okay. But this would not be a novice project, as you'd need to also build power supplies for each, which as I recall use variable frequency supplies.
WOW...that is a very tempting offer. Like you, repairing or rebuilding the planet analogs is not in my skill set. In fact, I would say it is a little scary, the more I think about it. If you had some actual planet projectors or a moon projector, I would certainly take you up on that. The analogs, I think I will have to pass on for now. But believe me I appreciate the offer. I wonder if the fellow at the planetarium museum could use them? It might also be a good place for them to find a 'home'.
Posted by: Charlie Miller Nov 4 2013, 01:18 PM
QUOTE(tomoarnold @ Nov 4 2013, 02:03 PM) *
WOW...that is a very tempting offer. Like you, repairing or rebuilding the planet analogs is not in my skill set. In fact, I would say it is a little scary, the more I think about it. If you had some actual planet projectors or a moon projector, I would certainly take you up on that. The analogs, I think I will have to pass on for now. But believe me I appreciate the offer. I wonder if the fellow at the planetarium museum could use them? It might also be a good place for them to find a 'home'.
I've thought of powering them up just as a demonstration of an analog computer. Most planetarium-savvy people probably have better stuff. I'm still annoyed that I bought them!
My early home-made design used rotating mirrors driven by the ol' Hankcraft d.c. motors. It was a pretty primititve idea. Now, I'm building planet projectors using 2W LED's... way better than the typically incandescent (tho I'm cutting down output quite a bit by imposing a small "disk" rather than using pinhole projection. Along the lines of the ol Nova III's. Sheez, put me in a museum.
I also have a taken-apart Spitz / Nova III that I'd likely give away I didn't get the base electronics... i.e. the stuff that powers the xenon arc lamp. And its star ball is inferior to the Spitz A3 design.
Posted by: tomoarnold Nov 4 2013, 01:25 PM
QUOTE(Charlie Miller @ Nov 4 2013, 02:18 PM) *
I've thought of powering them up just as a demonstration of an analog computer. Most planetarium-savvy people probably have better stuff. I'm still annoyed that I bought them!
My early home-made design used rotating mirrors driven by the ol' Hankcraft d.c. motors. It was a pretty primititve idea. Now, I'm building planet projectors using 2W LED's... way better than the typically incandescent (tho I'm cutting down output quite a bit by imposing a small "disk" rather than using pinhole projection. Along the lines of the ol Nova III's. Sheez, put me in a museum.
I also have a taken-apart Spitz / Nova III that I'd likely give away I didn't get the base electronics... i.e. the stuff that powers the xenon arc lamp. And its star ball is inferior to the Spitz A3 design.
Charlie;
Your slip ring designs are a work of art!! I looked at the photo in total amazement. It just reminds me of the work of true artisans of the planetarium. I am speaking of the Korkoz brothers that built the one-of-a-kind machine for Boston. Please keep of the good work. I am anxious to see your finished product.
Posted by: Charlie Miller Nov 4 2013, 01:54 PM
QUOTE(tomoarnold @ Nov 4 2013, 02:25 PM) *
Charlie;
Your slip ring designs are a work of art!! I looked at the photo in total amazement. It just reminds me of the work of true artisans of the planetarium. I am speaking of the Korkoz brothers that built the one-of-a-kind machine for Boston. Please keep of the good work. I am anxious to see your finished product.
Thanks, but it really just is old-fashioned DIY stuff that people used to do in their basements.... but is now a dying activity. I think that planetarium equipment, for many on this forum, is attractive because:
1) basic optics fun
2) basic electric circuits diddling
3) a desire to be precise, inventive, and maybe creative..
4) plus the goal of using the above to create a cool illusion. ....motivates many.
It saddens me that I'm mothballing my public outreach efforts, as i could never get city or university leaders on board. IT IS CRAZY: Iowa City has this wonderful strength of being the former home of James Van Allen. The university built a large dish antenna to get satellite telemetry right to the labs here. James Van Allen worked on the V2's... a decade before NASA was founded. He launched high-alt wx balloons from the small, local airport. the UI has had electronics on tens of NASA missions. It is one of the very few universities that made entire satellites!
Yet I cannot penetrate the Administration of the university... the Inner Sanctum... that will give the go-ahead to build a new $7 million boat house for a low-profile sport. I think it is crazy that they don't understand the huge golden egg that they are ignoring... and for what?
So I am the picture of frustration. Part of it is the insularity of university departments, a negative view toward doing outreach by many faculty (yeah... you can do it, but, ahem, us?) and the highly insular Upper Admin, which sets its own priorities and have their salaries paid by outside grants won... by others! I had a UI astronomy professor answer my challenge (all other big 10 schools have a planetarium, but not Iowa) with a dismissive answer: "well, all the others are old", which is not strictly true and seemed a bit condescending. Why would someone turn down an offer to help boost physics and astronomy?
So for 4 years, I've had a beautiful, fully functional Spitz A4 projector in my living room... thinking it would be easy to see things through. Boy was I wrong. Meanwhile, there's all this noise about STEM STEM STEM (reminding me of SPAM SPAM SPAM SPAM) which emphasizes Lego Leagues (parts never offered at a discount!) over passionate people talking about those great momemts of science.
It really is depressing. Basically: NASA was the catalyst 50 years ago. Now it's corporate-like efforts. One would THINK universities would lead the way on pushing science, but nope. Recently, my university spent $9 million on a new "latest tech" visual and sound system for the football games. But a pilot program to increase love/knowledge of science? Not so much.
Sorry for rant, but I tried for 3 years to push a non-profit-org effort and got nowhere. One last example. I made entreaties to the local school district, but was told "no thanks" to providing planetarium shows to kids. However, one school here paid a for-profit out-of-state company $1625 to bring a blow-up dome and show pre-canned shows run by a non scientist. Oh, and the school district allows yo-yo salespeople in my daughter's grade school every two years to sell yo-yo's on class time.
It's all a bit hard to take.
Posted by: tomoarnold Nov 4 2013, 02:28 PM
QUOTE(Charlie Miller @ Nov 4 2013, 02:54 PM) *
Thanks, but it really just is old-fashioned DIY stuff that people used to do in their basements.... but is now a dying activity. I think that planetarium equipment, for many on this forum, is attractive because:
1) basic optics fun
2) basic electric circuits diddling
3) a desire to be precise, inventive, and maybe creative..
4) plus the goal of using the above to create a cool illusion. ....motivates many.
It saddens me that I'm mothballing my public outreach efforts, as i could never get city or university leaders on board. IT IS CRAZY: Iowa City has this wonderful strength of being the former home of James Van Allen. The university built a large dish antenna to get satellite telemetry right to the labs here. James Van Allen worked on the V2's... a decade before NASA was founded. He launched high-alt wx balloons from the small, local airport. the UI has had electronics on tens of NASA missions. It is one of the very few universities that made entire satellites!
Yet I cannot penetrate the Administration of the university... the Inner Sanctum... that will give the go-ahead to build a new $7 million boat house for a low-profile sport. I think it is crazy that they don't understand the huge golden egg that they are ignoring... and for what?
So I am the picture of frustration. Part of it is the insularity of university departments, a negative view toward doing outreach by many faculty (yeah... you can do it, but, ahem, us?) and the highly insular Upper Admin, which sets its own priorities and have their salaries paid by outside grants won... by others! I had a UI astronomy professor answer my challenge (all other big 10 schools have a planetarium, but not Iowa) with a dismissive answer: "well, all the others are old", which is not strictly true and seemed a bit condescending. Why would someone turn down an offer to help boost physics and astronomy?
So for 4 years, I've had a beautiful, fully functional Spitz A4 projector in my living room... thinking it would be easy to see things through. Boy was I wrong. Meanwhile, there's all this noise about STEM STEM STEM (reminding me of SPAM SPAM SPAM SPAM) which emphasizes Lego Leagues (parts never offered at a discount!) over passionate people talking about those great momemts of science.
It really is depressing. Basically: NASA was the catalyst 50 years ago. Now it's corporate-like efforts. One would THINK universities would lead the way on pushing science, but nope. Recently, my university spent $9 million on a new "latest tech" visual and sound system for the football games. But a pilot program to increase love/knowledge of science? Not so much.
Sorry for rant, but I tried for 3 years to push a non-profit-org effort and got nowhere. One last example. I made entreaties to the local school district, but was told "no thanks" to providing planetarium shows to kids. However, one school here paid a for-profit out-of-state company $1625 to bring a blow-up dome and show pre-canned shows run by a non scientist. Oh, and the school district allows yo-yo salespeople in my daughter's grade school every two years to sell yo-yo's on class time.
It's all a bit hard to take.
I met with the same resistance. Teaching math just out of college, I got the Superintendent interested in building a planetarium, only to have it shot down by the school board in lieu of a new score board for the football stadium. (That was a real kick in the gut!) Later I tried to interest the town council in building a museum/planetarium complex only to be told that there was no interest. Then later as director in Dallas, I thought I had Ross Perot interested in building a 60' planetarium extension to the Science Place Museum to feature a Zeiss VI. Then the museum board countered with building an extension to the museum saying there was little interest in astronomy because NASA was floundering. I quit over that one. That was 1986, walking away from a Minolta MS8. I never touched a planetarium again until my A3 starball arrived last week. Yes it was emotional.
So you are not alone. I even tried later to interest another school system in Colorado. But they bought computers instead, saying technology was more important that science. The reality is the excitement we saw in the 1960s over going to the moon is what allowed a generation to dream of space. And the planetarium was at the center of that storm. When NASA died, the excitement died with it, except for those of us left that can still hang on to the vision of space travel and astronomy. It is still a shame that few in this generation will ever experience the awe and wonder of a truly dramatic planetarium show presented by someone that actually cares about what they are doing. It is just an example why this country has fallen so far behind in math and science. Priorities are misplaced in sports and other entertainment genres.
Posted by: Charlie Miller Nov 4 2013, 02:50 PM
QUOTE(tomoarnold @ Nov 4 2013, 03:28 PM) *
I met with the same resistance. Teaching math just out of college, I got the Superintendent interested in building a planetarium, only to have it shot down by the school board in lieu of a new score board for the football stadium. (That was a real kick in the gut!) Later I tried to interest the town council in building a museum/planetarium complex only to be told that there was no interest. Then later as director in Dallas, I thought I had Ross Perot interested in building a 60' planetarium extension to the Science Place Museum to feature a Zeiss VI. Then the museum board countered with building an extension to the museum saying there was little interest in astronomy because NASA was floundering. I quit over that one. That was 1986, walking away from a Minolta MS8. I never touched a planetarium again until my A3 starball arrived last week. Yes it was emotional.
So you are not alone. I even tried later to interest another school system in Colorado. But they bought computers instead, saying technology was more important that science. The reality is the excitement we saw in the 1960s over going to the moon is what allowed a generation to dream of space. And the planetarium was at the center of that storm. When NASA died, the excitement died with it, except for those of us left that can still hang on to the vision of space travel and astronomy. It is still a shame that few in this generation will ever experience the awe and wonder of a truly dramatic planetarium show presented by someone that actually cares about what they are doing. It is just an example why this country has fallen so far behind in math and science. Priorities are misplaced in sports and other entertainment genres.
Oh that is all terrible... and the naysayers are just WRONG. Space science is STILL perhaps the top most popular areas for kids. Planetariums have, perhaps shot themselves in the foot for going for the "canned shows", which are DEADLY. So around 1966, NASA's budget was HUGE... 4.5% of the federal budget. Guess what? It got a lot of people interested in science and engineering careers. Since then, their budget's floated around 0.5%. Sometimes it takes big pushes to make things happen.
The logical "carrier", I believe are the universities, which are some of the biggest "users" (and I mean that in a negative sense!) of PhD's So it would just be a matter of thinking about "enlightened" SELF INTEREST to boost public awareness of science. Instead, one gets the lazy and dishonest answer that "this is not within the University's mission". Yeah, neither is the very lightly attended Sport Hall of Fame here in Iowa City. And was 7$million REALLY needed for a boat house to store... boats?
This is what happens when institutions get middle-aged. Their bureaucracies take over, tenure creates a body of people with little interest in the university's future, and the mission is lost. This all results in the public's loss of respect for universities.... when hiding damaging evidence against a football player is more important than, say, a modest effort to boost science.
Neil deGrasse Tysonn spoke here to a SRO crowd (tho not one paper, radio station, or tv station covered it) and noted his view that the U.S. has NEVER been that invested in science. I think I agree.
It's hard to see --- in one's lifetime -- for our society to become so BORING.
Posted by: tomoarnold Nov 4 2013, 03:03 PM
QUOTE(Charlie Miller @ Nov 4 2013, 03:50 PM) *
Oh that is all terrible... and the naysayers are just WRONG. Space science is STILL perhaps the top most popular areas for kids. Planetariums have, perhaps shot themselves in the foot for going for the "canned shows", which are DEADLY. So around 1966, NASA's budget was HUGE... 4.5% of the federal budget. Guess what? It got a lot of people interested in science and engineering careers. Since then, their budget's floated around 0.5%. Sometimes it takes big pushes to make things happen.
The logical "carrier", I believe are the universities, which are some of the biggest "users" (and I mean that in a negative sense!) of PhD's So it would just be a matter of thinking about "enlightened" SELF INTEREST to boost public awareness of science. Instead, one gets the lazy and dishonest answer that "this is not within the University's mission". Yeah, neither is the very lightly attended Sport Hall of Fame here in Iowa City. And was 7$million REALLY needed for a boat house to store... boats?
This is what happens when institutions get middle-aged. Their bureaucracies take over, tenure creates a body of people with little interest in the university's future, and the mission is lost. This all results in the public's loss of respect for universities.... when hiding damaging evidence against a football player is more important than, say, a modest effort to boost science.
Neil deGrasse Tysonn spoke here to a SRO crowd (tho not one paper, radio station, or tv station covered it) and noted his view that the U.S. has NEVER been that invested in science. I think I agree.
It's hard to see --- in one's lifetime -- for our society to become so BORING.
Well said Charlie. Our society IS boring. It appears as though China may have picked up the banner and even be the first to return to the moon. While here we set watching football and only interested in what team will make the playoffs. It is a sad epitaph for a country that had the Universe ..'by the tail'. Who knows what will become of Mars. Perhaps it will actually be a private company that lands there first. Just think what could have been had people been more interested in science. You might have actually had the media show interest in Dr. Tysons talk. I would liked to have heard what he had to say myself!!!
Hi folks,
It has been a long time since I've posted. Had some tough times in the employment area (I would not advise anyone to aim for non-tenure positions in academic research!).
But anyway, I have been working on my home-built to make it better for outreach activities (did 5 such event this year). So far I've added:
1. A "pico" video projector (about the size of a cigarette case, with an LED as the light source). Good enough for bringing video content into the dome.
2. A moon projector, using the several moon-phase transparencies tHat I previously posted (I went for about a 1 degree sized moon). Basically used the old Nova III approach, but with better images. Light source: a 1W LED.
3. A Jupiter or Venus projector. Moves on the main axis, but not on any motor drive.
4. Finally, slip rings for the star bulb. This eliminates a significant drawback of twisted and broken wires. Here is a pic of the original design of the brush (a simple piece of brass). The second iteration involved soldering 6 small brass rods on a piece of brass, grinding flat areas on them, then bending them.
More pics later. My nonprofit is barely hobbling along. Part of this is my fault. I am not a businessman or salesman. A real problem these days when the confidence game seems SO important for biz promotion.
Posted by: Ron Walker Nov 28 2012, 09:12 AM
Do the brushes have any "spring" to them? The thing I found when using normal materials is that they tended to not hold contact for very long. Spring steel or an actual spring was needed to hold the brushes in place on the ring. I found that the simple contact arms from old relays worked rather well for such slow turning contacts.
Posted by: Charlie Miller Nov 28 2012, 10:52 AM
Hi, Ron,
Yeah, I agree. I'd like to use a spring steel approach, but one problem is that I've lost access to a machine shop, so forming nice parts (like the brush I made out of brass) isn't easy with my tools (or perhaps my hands).
So what I have now is WAY better than constantly ripping up wires (pretty damn crude!), but i suspect I'll need a better revision.
c.
Posted by: Charlie Miller Nov 30 2012, 07:34 AM
Projector progress, cont'd...
Here is an image of the slip ring assembly mounted to the southern disk of the star cylinder. Brush tension is maintained by the spring assembly.
This took me forever to get around to, in part b/c I no longer have access to a machine shop with donated labor.
I found (on the Internets) a way to use glossy magazine paper to create a mask transfer (using a toner-based printer). That pattern (for the rings) was then transferred to copper clad board via heat from a household iron. It worked pretty good, though I had to beef up the resist pattern with nail polish (perhaps I did not have the copper surface clean enough?) Thus the wiggliness of the rings in spots.
Early tests look good. Hope it works... Now need to build another one for the electrics south of the declination axis.
Posted by: SteveDurham Dec 1 2012, 07:00 PM
Looks PDG to me.....nice work!
Steve
Posted by: moonmagic Dec 2 2012, 05:56 PM
Looks VERY good to me! mm
Posted by: tomoarnold Nov 4 2013, 11:31 AM
QUOTE(Charlie Miller @ Nov 30 2012, 08:34 AM) *
Projector progress, cont'd...
Here is an image of the slip ring assembly mounted to the southern disk of the star cylinder. Brush tension is maintained by the spring assembly.
This took me forever to get around to, in part b/c I no longer have access to a machine shop with donated labor.
I found (on the Internets) a way to use glossy magazine paper to create a mask transfer (using a toner-based printer). That pattern (for the rings) was then transferred to copper clad board via heat from a household iron. It worked pretty good, though I had to beef up the resist pattern with nail polish (perhaps I did not have the copper surface clean enough?) Thus the wiggliness of the rings in spots.
Early tests look good. Hope it works... Now need to build another one for the electrics south of the declination axis.
Hi Charlie;
Your slip ring design is impressive! Do you have a photo of the instrument as it now stands? I would really like to too get an idea of your plans. I am in the process of building a machine with an A3 starball.
Tom
Posted by: Charlie Miller Nov 4 2013, 11:38 AM
QUOTE(tomoarnold @ Nov 4 2013, 12:31 PM) *
Hi Charlie;
Your slip ring design is impressive! Do you have a photo of the instrument as it now stands? I would really like to too get an idea of your plans. I am in the process of building a machine with an A3 starball.
Tom
Hi there.
Well, let me take a picture. I'll be setting up my projector for my last community outreach (my business plan failed rather definitively sad.gif ). I don't have an up-to-date image. An "earlier photo" (hmmm... as in an obit) is on my website at www.RediscoverScience.org... look under the "about us" tab and then the "material resources" page.
Probably a design weakness of my slip rings is the use of copper for the brushes. Yes, they are spring loaded, but I think that the use of spring metal might be a bit better. There's the phosphor alloy that is supposed to be good. But I had trouble cutting each brush into the series of parallel tines. Another possibility is to use the brush material used in the model slot-cars. But eventually, time limits all solutions or obsessive-anality!
Posted by: Charlie Miller Nov 4 2013, 11:45 AM
QUOTE(Charlie Miller @ Nov 4 2013, 12:38 PM) *
Hi there.
Well, let me take a picture. I'll be setting up my projector for my last community outreach (my business plan failed rather definitively sad.gif ). I don't have an up-to-date image. An "earlier photo" (hmmm... as in an obit) is on my website at www.RediscoverScience.org... look under the "about us" tab and then the "material resources" page.
Ah, the classic A3.... what needs to be done with it? Are you just starting with the star-ball only?
Tom... I purchased a set of A3P planet analogs... unfortunately from a sort of charlatan. They were shipped without the mirrors and most of the co-axial (rod-inside-tubing) parts are damaged. I'd consider giving them away for the cost of shipping, if you wanted to go that far. I will not say how much I paid for them (way too much). But they are just collecting dust and reminding me of a rather crappy business deal by a dealer in Florida who was reluctant to describe their condition. I'm assuming the analog computers of each are okay. But this would not be a novice project, as you'd need to also build power supplies for each, which as I recall use variable frequency supplies.
Posted by: Ron Walker Nov 4 2013, 12:56 PM
QUOTE(Charlie Miller @ Nov 4 2013, 11:45 AM) *
Tom... I purchased a set of A3P planet analogs... unfortunately from a sort of charlatan. They were shipped without the mirrors and most of the co-axial (rod-inside-tubing) parts are damaged. I'd consider giving them away for the cost of shipping, if you wanted to go that far. I will not say how much I paid for them (way too much). But they are just collecting dust and reminding me of a rather crappy business deal by a dealer in Florida who was reluctant to describe their condition. I'm assuming the analog computers of each are okay. But this would not be a novice project, as you'd need to also build power supplies for each, which as I recall use variable frequency supplies.
Or you could do a mechanical retrofit like I did. I wonder if your "crappy business dealer in Florida" is the same as mine? As for brushes, I find that the contact units from surplus large relays work quite well. They not only have the spring tension but a contact bob on the end as well.
Tom, you will never get a deal offer like that again, I'd jump on it. Though personally I think Charlie should get something for his investment.
Posted by: tomoarnold Nov 4 2013, 01:03 PM
QUOTE(Charlie Miller @ Nov 4 2013, 12:45 PM) *
Tom... I purchased a set of A3P planet analogs... unfortunately from a sort of charlatan. They were shipped without the mirrors and most of the co-axial (rod-inside-tubing) parts are damaged. I'd consider giving them away for the cost of shipping, if you wanted to go that far. I will not say how much I paid for them (way too much). But they are just collecting dust and reminding me of a rather crappy business deal by a dealer in Florida who was reluctant to describe their condition. I'm assuming the analog computers of each are okay. But this would not be a novice project, as you'd need to also build power supplies for each, which as I recall use variable frequency supplies.
WOW...that is a very tempting offer. Like you, repairing or rebuilding the planet analogs is not in my skill set. In fact, I would say it is a little scary, the more I think about it. If you had some actual planet projectors or a moon projector, I would certainly take you up on that. The analogs, I think I will have to pass on for now. But believe me I appreciate the offer. I wonder if the fellow at the planetarium museum could use them? It might also be a good place for them to find a 'home'.
Posted by: Charlie Miller Nov 4 2013, 01:18 PM
QUOTE(tomoarnold @ Nov 4 2013, 02:03 PM) *
WOW...that is a very tempting offer. Like you, repairing or rebuilding the planet analogs is not in my skill set. In fact, I would say it is a little scary, the more I think about it. If you had some actual planet projectors or a moon projector, I would certainly take you up on that. The analogs, I think I will have to pass on for now. But believe me I appreciate the offer. I wonder if the fellow at the planetarium museum could use them? It might also be a good place for them to find a 'home'.
I've thought of powering them up just as a demonstration of an analog computer. Most planetarium-savvy people probably have better stuff. I'm still annoyed that I bought them!
My early home-made design used rotating mirrors driven by the ol' Hankcraft d.c. motors. It was a pretty primititve idea. Now, I'm building planet projectors using 2W LED's... way better than the typically incandescent (tho I'm cutting down output quite a bit by imposing a small "disk" rather than using pinhole projection. Along the lines of the ol Nova III's. Sheez, put me in a museum.
I also have a taken-apart Spitz / Nova III that I'd likely give away I didn't get the base electronics... i.e. the stuff that powers the xenon arc lamp. And its star ball is inferior to the Spitz A3 design.
Posted by: tomoarnold Nov 4 2013, 01:25 PM
QUOTE(Charlie Miller @ Nov 4 2013, 02:18 PM) *
I've thought of powering them up just as a demonstration of an analog computer. Most planetarium-savvy people probably have better stuff. I'm still annoyed that I bought them!
My early home-made design used rotating mirrors driven by the ol' Hankcraft d.c. motors. It was a pretty primititve idea. Now, I'm building planet projectors using 2W LED's... way better than the typically incandescent (tho I'm cutting down output quite a bit by imposing a small "disk" rather than using pinhole projection. Along the lines of the ol Nova III's. Sheez, put me in a museum.
I also have a taken-apart Spitz / Nova III that I'd likely give away I didn't get the base electronics... i.e. the stuff that powers the xenon arc lamp. And its star ball is inferior to the Spitz A3 design.
Charlie;
Your slip ring designs are a work of art!! I looked at the photo in total amazement. It just reminds me of the work of true artisans of the planetarium. I am speaking of the Korkoz brothers that built the one-of-a-kind machine for Boston. Please keep of the good work. I am anxious to see your finished product.
Posted by: Charlie Miller Nov 4 2013, 01:54 PM
QUOTE(tomoarnold @ Nov 4 2013, 02:25 PM) *
Charlie;
Your slip ring designs are a work of art!! I looked at the photo in total amazement. It just reminds me of the work of true artisans of the planetarium. I am speaking of the Korkoz brothers that built the one-of-a-kind machine for Boston. Please keep of the good work. I am anxious to see your finished product.
Thanks, but it really just is old-fashioned DIY stuff that people used to do in their basements.... but is now a dying activity. I think that planetarium equipment, for many on this forum, is attractive because:
1) basic optics fun
2) basic electric circuits diddling
3) a desire to be precise, inventive, and maybe creative..
4) plus the goal of using the above to create a cool illusion. ....motivates many.
It saddens me that I'm mothballing my public outreach efforts, as i could never get city or university leaders on board. IT IS CRAZY: Iowa City has this wonderful strength of being the former home of James Van Allen. The university built a large dish antenna to get satellite telemetry right to the labs here. James Van Allen worked on the V2's... a decade before NASA was founded. He launched high-alt wx balloons from the small, local airport. the UI has had electronics on tens of NASA missions. It is one of the very few universities that made entire satellites!
Yet I cannot penetrate the Administration of the university... the Inner Sanctum... that will give the go-ahead to build a new $7 million boat house for a low-profile sport. I think it is crazy that they don't understand the huge golden egg that they are ignoring... and for what?
So I am the picture of frustration. Part of it is the insularity of university departments, a negative view toward doing outreach by many faculty (yeah... you can do it, but, ahem, us?) and the highly insular Upper Admin, which sets its own priorities and have their salaries paid by outside grants won... by others! I had a UI astronomy professor answer my challenge (all other big 10 schools have a planetarium, but not Iowa) with a dismissive answer: "well, all the others are old", which is not strictly true and seemed a bit condescending. Why would someone turn down an offer to help boost physics and astronomy?
So for 4 years, I've had a beautiful, fully functional Spitz A4 projector in my living room... thinking it would be easy to see things through. Boy was I wrong. Meanwhile, there's all this noise about STEM STEM STEM (reminding me of SPAM SPAM SPAM SPAM) which emphasizes Lego Leagues (parts never offered at a discount!) over passionate people talking about those great momemts of science.
It really is depressing. Basically: NASA was the catalyst 50 years ago. Now it's corporate-like efforts. One would THINK universities would lead the way on pushing science, but nope. Recently, my university spent $9 million on a new "latest tech" visual and sound system for the football games. But a pilot program to increase love/knowledge of science? Not so much.
Sorry for rant, but I tried for 3 years to push a non-profit-org effort and got nowhere. One last example. I made entreaties to the local school district, but was told "no thanks" to providing planetarium shows to kids. However, one school here paid a for-profit out-of-state company $1625 to bring a blow-up dome and show pre-canned shows run by a non scientist. Oh, and the school district allows yo-yo salespeople in my daughter's grade school every two years to sell yo-yo's on class time.
It's all a bit hard to take.
Posted by: tomoarnold Nov 4 2013, 02:28 PM
QUOTE(Charlie Miller @ Nov 4 2013, 02:54 PM) *
Thanks, but it really just is old-fashioned DIY stuff that people used to do in their basements.... but is now a dying activity. I think that planetarium equipment, for many on this forum, is attractive because:
1) basic optics fun
2) basic electric circuits diddling
3) a desire to be precise, inventive, and maybe creative..
4) plus the goal of using the above to create a cool illusion. ....motivates many.
It saddens me that I'm mothballing my public outreach efforts, as i could never get city or university leaders on board. IT IS CRAZY: Iowa City has this wonderful strength of being the former home of James Van Allen. The university built a large dish antenna to get satellite telemetry right to the labs here. James Van Allen worked on the V2's... a decade before NASA was founded. He launched high-alt wx balloons from the small, local airport. the UI has had electronics on tens of NASA missions. It is one of the very few universities that made entire satellites!
Yet I cannot penetrate the Administration of the university... the Inner Sanctum... that will give the go-ahead to build a new $7 million boat house for a low-profile sport. I think it is crazy that they don't understand the huge golden egg that they are ignoring... and for what?
So I am the picture of frustration. Part of it is the insularity of university departments, a negative view toward doing outreach by many faculty (yeah... you can do it, but, ahem, us?) and the highly insular Upper Admin, which sets its own priorities and have their salaries paid by outside grants won... by others! I had a UI astronomy professor answer my challenge (all other big 10 schools have a planetarium, but not Iowa) with a dismissive answer: "well, all the others are old", which is not strictly true and seemed a bit condescending. Why would someone turn down an offer to help boost physics and astronomy?
So for 4 years, I've had a beautiful, fully functional Spitz A4 projector in my living room... thinking it would be easy to see things through. Boy was I wrong. Meanwhile, there's all this noise about STEM STEM STEM (reminding me of SPAM SPAM SPAM SPAM) which emphasizes Lego Leagues (parts never offered at a discount!) over passionate people talking about those great momemts of science.
It really is depressing. Basically: NASA was the catalyst 50 years ago. Now it's corporate-like efforts. One would THINK universities would lead the way on pushing science, but nope. Recently, my university spent $9 million on a new "latest tech" visual and sound system for the football games. But a pilot program to increase love/knowledge of science? Not so much.
Sorry for rant, but I tried for 3 years to push a non-profit-org effort and got nowhere. One last example. I made entreaties to the local school district, but was told "no thanks" to providing planetarium shows to kids. However, one school here paid a for-profit out-of-state company $1625 to bring a blow-up dome and show pre-canned shows run by a non scientist. Oh, and the school district allows yo-yo salespeople in my daughter's grade school every two years to sell yo-yo's on class time.
It's all a bit hard to take.
I met with the same resistance. Teaching math just out of college, I got the Superintendent interested in building a planetarium, only to have it shot down by the school board in lieu of a new score board for the football stadium. (That was a real kick in the gut!) Later I tried to interest the town council in building a museum/planetarium complex only to be told that there was no interest. Then later as director in Dallas, I thought I had Ross Perot interested in building a 60' planetarium extension to the Science Place Museum to feature a Zeiss VI. Then the museum board countered with building an extension to the museum saying there was little interest in astronomy because NASA was floundering. I quit over that one. That was 1986, walking away from a Minolta MS8. I never touched a planetarium again until my A3 starball arrived last week. Yes it was emotional.
So you are not alone. I even tried later to interest another school system in Colorado. But they bought computers instead, saying technology was more important that science. The reality is the excitement we saw in the 1960s over going to the moon is what allowed a generation to dream of space. And the planetarium was at the center of that storm. When NASA died, the excitement died with it, except for those of us left that can still hang on to the vision of space travel and astronomy. It is still a shame that few in this generation will ever experience the awe and wonder of a truly dramatic planetarium show presented by someone that actually cares about what they are doing. It is just an example why this country has fallen so far behind in math and science. Priorities are misplaced in sports and other entertainment genres.
Posted by: Charlie Miller Nov 4 2013, 02:50 PM
QUOTE(tomoarnold @ Nov 4 2013, 03:28 PM) *
I met with the same resistance. Teaching math just out of college, I got the Superintendent interested in building a planetarium, only to have it shot down by the school board in lieu of a new score board for the football stadium. (That was a real kick in the gut!) Later I tried to interest the town council in building a museum/planetarium complex only to be told that there was no interest. Then later as director in Dallas, I thought I had Ross Perot interested in building a 60' planetarium extension to the Science Place Museum to feature a Zeiss VI. Then the museum board countered with building an extension to the museum saying there was little interest in astronomy because NASA was floundering. I quit over that one. That was 1986, walking away from a Minolta MS8. I never touched a planetarium again until my A3 starball arrived last week. Yes it was emotional.
So you are not alone. I even tried later to interest another school system in Colorado. But they bought computers instead, saying technology was more important that science. The reality is the excitement we saw in the 1960s over going to the moon is what allowed a generation to dream of space. And the planetarium was at the center of that storm. When NASA died, the excitement died with it, except for those of us left that can still hang on to the vision of space travel and astronomy. It is still a shame that few in this generation will ever experience the awe and wonder of a truly dramatic planetarium show presented by someone that actually cares about what they are doing. It is just an example why this country has fallen so far behind in math and science. Priorities are misplaced in sports and other entertainment genres.
Oh that is all terrible... and the naysayers are just WRONG. Space science is STILL perhaps the top most popular areas for kids. Planetariums have, perhaps shot themselves in the foot for going for the "canned shows", which are DEADLY. So around 1966, NASA's budget was HUGE... 4.5% of the federal budget. Guess what? It got a lot of people interested in science and engineering careers. Since then, their budget's floated around 0.5%. Sometimes it takes big pushes to make things happen.
The logical "carrier", I believe are the universities, which are some of the biggest "users" (and I mean that in a negative sense!) of PhD's So it would just be a matter of thinking about "enlightened" SELF INTEREST to boost public awareness of science. Instead, one gets the lazy and dishonest answer that "this is not within the University's mission". Yeah, neither is the very lightly attended Sport Hall of Fame here in Iowa City. And was 7$million REALLY needed for a boat house to store... boats?
This is what happens when institutions get middle-aged. Their bureaucracies take over, tenure creates a body of people with little interest in the university's future, and the mission is lost. This all results in the public's loss of respect for universities.... when hiding damaging evidence against a football player is more important than, say, a modest effort to boost science.
Neil deGrasse Tysonn spoke here to a SRO crowd (tho not one paper, radio station, or tv station covered it) and noted his view that the U.S. has NEVER been that invested in science. I think I agree.
It's hard to see --- in one's lifetime -- for our society to become so BORING.
Posted by: tomoarnold Nov 4 2013, 03:03 PM
QUOTE(Charlie Miller @ Nov 4 2013, 03:50 PM) *
Oh that is all terrible... and the naysayers are just WRONG. Space science is STILL perhaps the top most popular areas for kids. Planetariums have, perhaps shot themselves in the foot for going for the "canned shows", which are DEADLY. So around 1966, NASA's budget was HUGE... 4.5% of the federal budget. Guess what? It got a lot of people interested in science and engineering careers. Since then, their budget's floated around 0.5%. Sometimes it takes big pushes to make things happen.
The logical "carrier", I believe are the universities, which are some of the biggest "users" (and I mean that in a negative sense!) of PhD's So it would just be a matter of thinking about "enlightened" SELF INTEREST to boost public awareness of science. Instead, one gets the lazy and dishonest answer that "this is not within the University's mission". Yeah, neither is the very lightly attended Sport Hall of Fame here in Iowa City. And was 7$million REALLY needed for a boat house to store... boats?
This is what happens when institutions get middle-aged. Their bureaucracies take over, tenure creates a body of people with little interest in the university's future, and the mission is lost. This all results in the public's loss of respect for universities.... when hiding damaging evidence against a football player is more important than, say, a modest effort to boost science.
Neil deGrasse Tysonn spoke here to a SRO crowd (tho not one paper, radio station, or tv station covered it) and noted his view that the U.S. has NEVER been that invested in science. I think I agree.
It's hard to see --- in one's lifetime -- for our society to become so BORING.
Well said Charlie. Our society IS boring. It appears as though China may have picked up the banner and even be the first to return to the moon. While here we set watching football and only interested in what team will make the playoffs. It is a sad epitaph for a country that had the Universe ..'by the tail'. Who knows what will become of Mars. Perhaps it will actually be a private company that lands there first. Just think what could have been had people been more interested in science. You might have actually had the media show interest in Dr. Tysons talk. I would liked to have heard what he had to say myself!!!