by SimplusDesign, published

Cosmo-Knob by SimplusDesign Apr 29, 2014

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43421Views 6982Downloads Found in Physics & Astronomy


Bring the stars inside with our homage to the cosmos!
Follow these simple steps to fill the room with the night's sky:

  1. print adapter and knob
  2. place adapter on iPhone
  3. attach knob to adapter
  4. turn on flashlight app
  5. turn off the lights and enjoy!

The model features northern hemisphere constellations - see if you can follow along with the map! - http://bit.ly/SeKMYM


  • iPhone 4s adapter
  • iPhone 5 adapter
  • Knob01 - 1/16" thick walls
  • Knob02 - 1/32" thick walls
  • Universal adapter

We hope you enjoy!
Simplus Design


Raft recommended for knob because of small surface area.

No support recommended.

The files are in INCHES. To convert to mm, scale model by 25.4 or use the "Inches -> mm" button in MakerWare.

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Does this NEED a phone to work? Or could I place over an LED? Seems like it would work fine, possibly need to enlarge a bit. I was thinking of wiring up some custom night lights for the kids....

No it does not and it can be placed over an LED

Will this work on iPhone 6s? Thanks,

Yes, please, one for galaxy s5!

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make one for galaxy s5!

This project is super cool. Is there an instructable on how to map a data set (such as a star field) on a 3d object?

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Only problem I have is the light isn't focused but that isn't a design flaw, it's just how the light behaves.

Can you make this for the iPhone 5C please!

This looks like a job for.... #diligentSnake aka our Form1

Good Job! Really good idea !

Has anyone had the problem where if you try to slice it with slicer it shows up really small and doesn't print anything? I have a Printrbot Plus and i am just wondering what i am doing wrong.

Hi! FYI, the file is in INCHES. To convert to mm, scale model by 25.4. This should increase the model size.

Thank You!

or you can go into the config tab and click the units of imported models and change it to inches

This is awesome!
I'll suggest, though, that it'd be much easier to print if the projection surface were flat, as you could print the knob "upside down". All you'd have to do is take the lines of the stars and project them through a plane instead of the curved shape you used.

Thanks Laird! We tried that in some of the earlier prototypes, this design worked and looked the best at the end of the day. We were also on a tight deadline, so we'd like to come back to it and add some improvements later down the road.

I tried to print this on a Replicator 2 last night and it failed twice at the same point. Just past the shoulder of the knob. Did you adjust any print settings? I used default with raft both times.

I have the same problem on the Replicator 2, printed on high settings.

What do you mean by failed? We have been successful at printing ours at a .25 layer height at about a speed of 75/140. Let us know if this helps!

I'll give it a try on those settings, thanks! By "failed," I mean that the newly printed layers above the shoulder weren't connected to the lower layers, almost as if they never bonded with it. It continued to print until completion, but the holes for the stars were very irregular, some of the were connected to eachother, etc. Tried it twice with the same results.
I'm going to try your settings now though.

I had that issue as well until I tried it with 70% infill and 4 shells, worked great

Brilliant. I want to go home to print it RIGHT NOW, and turn this sun down!

Thanks hope it turns out great!

It does, however I need to do some cleaning in the holes, the light projection is far to be clean. Anyway, it's nice :)

this is sick!!! amazing challenge entry. love it.

Thanks Joey!! It was a really fun challenge to come up with something new, enjoy!

Both STLs appear to be very small, even smaller than if the units were in inches. What scale should they be at?

Hi! The file is in INCHES. To convert to mm, scale model by 25.4 or use the "Inches -> mm" button in MakerWare.

i would totally print this if you made a iPod 5 adapter :)

This is fantastic design. Love the diagram too.

Thank you!! Hope you enjoy!

I was thinking to make a customisable one, is it possible>???

can you make one for the 5C please??

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