Author Options:

Any thoughts on constructing a lamp to project a spherical starfield? Answered

So, I have a friend's birthday coming up, and she's a creative dreamer type.  I stumbled upon an unattributed image of a lamp that projects a starfield, and immediately thought, "absolutely perfect!  but, can I make it?"

so, after a bit of thought,  I came up with most of a plan...

the base unit would have two dimmer switches on it: one for the lamp, the other for a small motor.

a stand would exit the base at about 15-20 degrees from vertical, and support the motor.

a small brush and ring system, or commercial electrical routing system would pass electricity to the lamp, which would be surrounded by a spherical (or n sided polygonal) lampshade that is translucent, passing very little light, except where it is drilled to create stars

My primary question is, has anyone seen something similar commercially?  aimed more at the design crowd than at kids or science buffs?

My secondary question is, what would be a good way to produce the star-screens, so as to not hand drill 2000 holes or so.


Master Beorn

7 years ago

IKEA used to have something akin to this, though simpler. It was a globe with star, moon and planet shapes cut out, with a halogen lamp inside. I got one for my boy's room and as it needed to be hardwired, I pulled the halogen lamp and replaced it with an LED bulb.

I think that something of this nature wouldn't be too hard. The rotating part isn't up my alley, but a hard plastic sphere with a rather bright bulb in it that has been pierced... But you said you didn't want to drill a million holes. Hmmm...


7 years ago

I'd be wondering if you could vacuum form a fresnel lens at low temp to a hemisphere and use a small flat disc to project the starfeild?


8 years ago

Just an update:

I found the light pictured in the image I included... Its called an "Astrostar Cosmos Lamp" and is sold as a kit on eBay.

They are dirt cheap ($5-$10 including shipping), but leave much to be desired in terms of build quality and "polish"... they also lack motorization.

I've ordered two, and plan to use the included panels to create a much better "Kozmos Lamp"

I will likely document the process as an instructable.


Reply 8 years ago

If anybody actually is following this, I have a plan for the rotation, involving:

@ 400 step/rev stepper motor  (http://www.phidgets.com/products.php?category=23&product_id=3302)
@ EasyDriver stepper driver board (http://www.sparkfun.com/products/10267)
@ 10 toothed pinion gear
@ 40 toothed gear with the bore drilled to ~8mm diameter
@ 1/4 inch mono audio Jack and Plug
@ epoxy/filler
@ PVC pipe and fittings

does anyone see the plan here?  Because I sure don't :-P


Reply 8 years ago

um... sometimes for motorization its easier to go with pre-existing rotating devices. Salvation army type stores often have a kitchen/hardware section where you find all sorts of interesting pre-geared motors. Nice slow geared motors are, electric can openers, BBQ rotisserie motors, lemon juicers etc... They also have the benefit of running of a simple plug, bang easy. You do have to be more careful in that they run off a simple plug, bang your dead. Key here is to keep the light source stationary but rotate the star shield instead. If all else fails, walmart sells several mechanical rotating lights, the kind that turn a column with a picture inside for about 12$ You want the plug in one, not the battery operated one. The all metal housing geared mot that is in this is crazy. Insane torque, delicious slow speed, nice mounting options, whisper quiet and a nice thick solid axle to attach what have you too.


Reply 8 years ago

although I'm not sure they'd be right for this project, which walmart lights are you talking about? I've seen sports themed rotating lights for about $50, but can't find any that list around $12... do you have a link or picture?