Planetarium Star Projectors

[SpitzSTP]

Working into the night.

[mixedgas]

[QUOTE=SpitzSTP;227844]Yes, these are Cermax type xenon short-arc lamps. I heard that they can explode so I try to be careful with them. One common application for these are in endoscopy where the light goes where the sun

For various reasons, I've been using them for years. A favorite toy of mine, if something so dangerous can be called a toy. I keep a few lamps around. I've used ones up to 1 Kilowatt. I also have some compact PSUs.
Agree ebay ones are over priced, but there is a guy in Boston, if I can find him, that sells 200 to 500 Watt modern P.E. PSUs around 50$ when he gets them.
Steve

[SpitzSTP]

[QUOTE=mixedgas;227869]

Yes, these are Cermax type xenon short-arc lamps. I heard that they can explode so I try to be careful with them. One common application for these are in endoscopy where the light goes where the sun

For various reasons, I've been using them for years. A favorite toy of mine, if something so dangerous can be called a toy. I keep a few lamps around. I've used ones up to 1 Kilowatt. I also have some compact PSUs.
Agree ebay ones are over priced, but there is a guy in Boston, if I can find him, that sells 200 to 500 Watt modern P.E. PSUs around 50$ when he gets them.
Steve

Steve, I have great interest in the modern PSU's, please let me know if you can find the fellow in Boston. Another application I have in mind, is to "up" the Starscape from 300W xenon to as bright as I can get it. I wonder what a 1 kilowatt bulb will be like, in this 4 foot diameter sphere. One notion is to mount each half of the Starscape starball (north and south hemispheres, total 10,000+ stars) into road cases and take them on the road. Do you have any pictures of 1 kilowatt bulbs and or psu's ? Please let me know if you run into anything like this ? I am attempting to morph a few of these machines into entertainment systems that will project star images bright enough to be seen over house lights as opposed to a completely darkened domed theater. from where they came.

Also, a shameless general appeal for collaborators and/or investment capital should anyone of a like mind happen upon this post. I have the machines.. tools.. truck.. and a dream. I would like to put the AVI Omniscan full-dome projection system on the road also. The unit pictured, is from the Fillmore East (NYC).

[SpitzSTP]

Mobile base for the Minolta Series IIB is complete. First step is to add the uprights for the central core. This machine came out of Indiana.

[SpitzSTP]

Central core mounted using the gantry crane.

[allthatwhichis]

Damn I want to see one of these close up; you need to start "Shopping" Florida Planetariums.

[chad]

Another application I have in mind, is to "up" the Starscape from 300W xenon to as bright as I can get it. I wonder what a 1 kilowatt bulb will be like

More than likley that will not work. The machine was designed with that exact lamp in mind, more specifically, the exact arc length in mind. When we converted the old spitz into a vomit comet effect we used a larger arc lamp. This resulted in bigger fuzzier comet looking things, not the pin point stars it used to have.

You can give it a whirl but I am about 99% sure you will not like the results if you are after a good star field.

chad

[SpitzSTP]

Point taken, and much appreciated ! Clearly, some experimentation is in order. This Minolta uses 500 watt incandescent bulbs. The starfield is crisp and bright. I don't think I will need to do anything to modify this particular machine. The planet cages and starballs get mounted next. These components are very heavy. First, they will get a good cleaning and the moving parts lubricated. All planets are optically reproduced along with the sun and moon. Alignment is critical, fortunately Ron in Cave Creek has told me exactly how to do this. Two of the mercury-filled eyelid weights are leaking and I dropped those off at Ron's today to be fixed. Fortunately I captured the loose mercury in a tupperware container as I have no idea where one can purchase mercury these days. The old mercury goes back in the tube which is then sealed with hot glue.

More than likley that will not work. The machine was designed with that exact lamp in mind, more specifically, the exact arc length in mind. When we converted the old spitz into a vomit comet effect we used a larger arc lamp. This resulted in bigger fuzzier comet looking things, not the pin point stars it used to have.

You can give it a whirl but I am about 99% sure you will not like the results if you are after a good star field.

chad

[chad]

That looks exactly like the Minolta we had at gates. Although I thought that ours had a 1k tungsten lamp, skinny long filament. I don't remember the model.

Any way. Neat stuff! I miss those big machines.

chad

[SpitzSTP]

That looks exactly like the Minolta we had at gates. Although I thought that ours had a 1k tungsten lamp, skinny long filament. I don't remember the model.

Any way. Neat stuff! I miss those big machines.

chad

I found a picture of the Gates Minolta so I posted it here, yes it looks very similar. I wonder what happened to the Gates Minolta. Perhaps to the great parts bin in the sky? Even the control console is similar. I have the northern hemisphere planet cage installed on this one after careful alignment of the sun and moon gear. I wouldn't be able to do this by myself without the gantry crane as the planet cages weigh about 60 - 70 pounds each.