Planetarium Star Projectors

[Soulstorm]

Remember seeing one of these as a kid, always thought they ran on a laser source, haven't seen one since this amazing thread! Blew me away at the time.
Returned to the same planetarium recently, the 20" scope was a jaw dropping experience, however they'd switched to projectors for the dome. Could see the aberration from the lenses right along the center of the dome but the experience was quite involving and immerse. Still remember the original star projectors were much sharper and much more realistic looking. Plus they looked a little like some of the droids in star wars.

Apparently the Zeiss projector in Auckland was retired in 2008. I could do some digging as to its current status, if any are interested.

[dar303]

Dear forum friends, it looks like I just got yet another mega time consuming hobby, thank you!

After a day of driving close to 600 kilometers the projector is safely tucked away in my lab next to a pile of argons and CO2's!
This is how it looked when I got to the museum:


It is in a quite sad shape, the two main (?) motors are gone along with most drivers, computer and interface.
It was mounted on a hydraulic platform so there was no podium except waht you see in the picture.
I however got two 20W lamp units with drivers and a incandescent dummy/service unit plus the lamp driver and the orrey (correct name?)


There wasn't many auxillary projectors and the "geocentric earth" projector was missing but I got a nice sattelite projector and some other smaller things.

The ball had some small dents but seemed ok, they told me it was once green but that they painted it matte black by first inserting 2000 sharpened sewing pins in the holes!
I got some history about it and a binder with original (blue!) blueprints and photocopies of import or freight documents. It had been in the museum for 25 years and was before that in a planetarium in Canada, I didn't see a name but I have a partial adress on one of the documents Ithink.


So what to do with it? I'm thinking of making a functional rebuild, I might not be able to turn it back into a scientific instrument but I will try to make it presentable and usable for people to see and enjoy again!
I will probably design or adapt new drivers and a control system to be housed in the base and make a hybrid digital analog control panel for it. A couple of friends that run an event/rave company has a very big roadcase that they will custom re-build for it if I get the thing running and they will also provide space for me to store it if I want so things are looking good even if it will take a lot of time.
I'm thinking of starting a thread over at Observatory Central since it may be a more appropriate place but I will be sure to post updates here too since it was you guys who started this!

Thank you guys!

[SpitzSTP]

WOW !!!!! Incredible !!!! GOOD JOB !!!!! Thank you for sharing this adventure, and I truly hope you will continue sharing the progress in getting your A3P operational. I truly hope to get more people like you posting in this section of PL, to keep it going. It IS appropriate on this board, as these projectors are definately photon-related and share a cozy relationship with lasers. Blending starfield displays with laser graphics has always been a passion of mine, along with care and restoration of vintage planetarium technology. A check of the hit counts on this thread confirms that there are others who appreciate this topic in general. Keep up the good work !!! And congratulations, for sparing another classic star projector from an uncertain fate. It is possible to simply restore the starball to operation - that is all you need to produce stars. The back half of the machine does the Sun, Moon and planets - but the orrery you have shown in the box, will also do that job too. Please keep posting here and many thanks, for sharing.

[SpitzSTP]

I am definately interested in what became of the Auckland Zeiss. These are all coming offline, and many will likely never be seen again. Recently in the USA, several have disappeared and another one is scheduled to come out in Boulder, CO at the Fiske. Alot of them wind up as static displays, never to operate again as the wiring and control systems are discarded. To me those are like taxidermy animals, they are dead as a stone. I would almost prefer to just remember them the way they were, when they were alive.

[m2b]

Remember seeing one of these as a kid, always thought they ran on a laser source, haven't seen one since this amazing thread! Blew me away at the time.
Returned to the same planetarium recently, the 20" scope was a jaw dropping experience, however they'd switched to projectors for the dome. Could see the aberration from the lenses right along the center of the dome but the experience was quite involving and immerse. Still remember the original star projectors were much sharper and much more realistic looking. Plus they looked a little like some of the droids in star wars.

Apparently the Zeiss projector in Auckland was retired in 2008. I could do some digging as to its current status, if any are interested.

That is the problem with the new video type projectors. Unless you have really big bucks, they will never come close to the sharpness and black sky background of the older projection models. It's kind of a two edge sword, I hate to see them replaced but I would never been able to afford one if the various entities didn't want to replace them. I also love the way they look, it's what turned me on to astronomy in the first place.

[m2b]

Dear forum friends, it looks like I just got yet another mega time consuming hobby, thank you!

After a day of driving close to 600 kilometers the projector is safely tucked away in my lab next to a pile of argons and CO2's!
This is how it looked when I got to the museum:


It is in a quite sad shape, the two main (?) motors are gone along with most drivers, computer and interface.
It was mounted on a hydraulic platform so there was no podium except waht you see in the picture.
I however got two 20W lamp units with drivers and a incandescent dummy/service unit plus the lamp driver and the orrey (correct name?)


There wasn't many auxillary projectors and the "geocentric earth" projector was missing but I got a nice sattelite projector and some other smaller things.

The ball had some small dents but seemed ok, they told me it was once green but that they painted it matte black by first inserting 2000 sharpened sewing pins in the holes!
I got some history about it and a binder with original (blue!) blueprints and photocopies of import or freight documents. It had been in the museum for 25 years and was before that in a planetarium in Canada, I didn't see a name but I have a partial adress on one of the documents Ithink.


So what to do with it? I'm thinking of making a functional rebuild, I might not be able to turn it back into a scientific instrument but I will try to make it presentable and usable for people to see and enjoy again!
I will probably design or adapt new drivers and a control system to be housed in the base and make a hybrid digital analog control panel for it. A couple of friends that run an event/rave company has a very big roadcase that they will custom re-build for it if I get the thing running and they will also provide space for me to store it if I want so things are looking good even if it will take a lot of time.
I'm thinking of starting a thread over at Observatory Central since it may be a more appropriate place but I will be sure to post updates here too since it was you guys who started this!

Thank you guys!

You have a nice machine there. Why they removed the drive motors from the base I'll never know. You need to check under the covers at each end of the East/West axis and see if the gearing is still there. It would be fairly easy to get the projector up and running again.

[m2b]

Yes, the dimensions for this van as mentioned should be big enough provided that the instrument is taken apart as m2b describes. The largest components of an A3P are the console (which you said you are not getting) and the wooden pedestal atop which the machine sits. The dimensions of the pedestal vary from installation to installation and were custom manufactured by Spitz to match the dome size and spring line height. The largest pedestal I have seen is about 5 feet tall and about 4 feet wide at the top, with a negative taper towards the bottom at about 3 to 3.5 feet. Given the dimensions of your van, it sounds like it will all fit although be sure to bring some packing materials - you will want to protect the star ball which is thin sheet brass and prone to denting. I always wrap them in bubble wrap and put them in a box all by itself, surrounded by stryrofoam peanuts. Be careful to disengage the worm drive gears on the central core by loosening the screws to allow for free movement during transport. It will be a good idea to have at least one person help you move the core, as they are difficult for one person to manage. Hopefully m2b will jump in to confirm these details, and adjust anything I have said. Please let us know if we can further assist, I am so glad to hear this machine will be saved from an uncertain fate. Many have already been destroyed and they stopped making them a long time ago. It would not be a bad idea to get a vehicle that is even larger than what you anticipate, just in case. Also, if the cables are still laying around, be sure to get those as well. They are grey multiconductor and very expensive to replace. Be careful with the planet cage (the back part of the machine), it needs to be in a box by itself and never lift it in such a way as to place stress on the delicate wire cage. These are prone to buckle under stress and if it breaks, it is next to impossible to fix or replace.

YES, what he said.

[dar303]

The gearing is all there, half of the flexible couplings and the transmission-axle (?) is gone along with the motors.
I'm thinking of replacing them with stepper motors since I have a lot of experience with that because I build CNC-machines and other mechatronic stuff. I have some different types of drivers and motors laying around, do anyone know what power and rpm the original motors were?

[m2b]

The gearing is all there, half of the flexible couplings and the transmission-axle (?) is gone along with the motors.
I'm thinking of replacing them with stepper motors since I have a lot of experience with that because I build CNC-machines and other mechatronic stuff. I have some different types of drivers and motors laying around, do anyone know what power and rpm the original motors were?

See this post and the next: http://www.observatorycentral.com/in...ndpost&p=19986

Make sure your stepper motors are small steps. Any small jerks in the system will show up magnified on an projection on a dome.

[dar303]

Ah, great!
5.4 in lb is 0.61N accordning to http://www.boltscience.com/pages/convert.htm and my motors have a 2N rating.
I have drivers with both 1000 and 10.000 microsteps and even one with "analog mode" that are used for star tracking telescopes, will try and see if that will be necessary.
1725 rpm / 18 is 95 rpm, I dont know what torque the motors have left at that RPM, they are speced at 1000 rpm I think but I guess I'll have to try!

I was thinking of putting the motors up on the worm drive with a belt drive instead of the shafts, do you see a problem with that? I read something about the motors obstructing the starfield in the thread, but is that only regarding projectors with dual starballs?
I could use a 1:2 or 1:4 pulley ratio to gain more torque if needed.