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Best RGB Pixel for a Ping Pong ball

Discussion in 'RGB Lights - Intelligent Pixels and 3-Channel RGB' started by CRPerryJr, Sep 17, 2010.

  1. CRPerryJr

    CRPerryJr New Elf

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    Hello everyone,

    I wasn't sure if I posted this in the proper forum category, so if I'm wrong, please move.

    I'm looking for suggestions on the best RGB LED to use a Ping Pong ball as a diffuser. My idea is to create a matrix of about 10x17 (170 pixels) and enclose the pixel in a Ping Pong ball, or something similar.

    I have already ordered my DMX dongle, and the TP3212.

    I found these for diffusers. (Cheap enough to replace as needed.)
    Amazon Ping Pong Balls

    I'm torn between these 2 Pixels. (I'm open to other suggestions as well.)
    Ray WU Straw Hat 6803 Pixel
    5050 2801 Pixel

    Here's what it would look like... What do you think?
     

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  2. neilric99

    neilric99 Full Time Elf

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    I like the idea on the ping-pong ball for a diffuser on a matrix, I am going to be creating a matrix of 15*24 rgb 2801 pixel nodes at 2" centers. now off to pick up some practice balls to see what they will look like on the test matrix.
     
  3. OP
    OP
    CRPerryJr

    CRPerryJr New Elf

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    Thanks! Just be aware....Ping Pong balls are not UV resistant. They will break down and turn yellow. (Even in storage.) That's why I still have to think of a way to easily change them, or find a comparable type of diffuser. (Opaque Plastic Christmas Bulbs?) But in a pinch, they'll do the job cheaply. (I hope.)
     
  4. AussiePhil

    AussiePhil Dedicated Elf Administrator

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    Hi

    I toyed with the idea of using ping pong balls in 2009 and eventually went a different way.

    One issue i had was that once you cut the hole in the ball they lost all their structural integrity, meaning it became real easy to have dents in them just from your fingers.
    Also it was hard to actually make a good hole. The idea that i hit on but never tested was to use the bench mounted router and a correctly sized router bit, never got round to making a little ball holder to keep fingers away from the router bit.

    As for pixel type, based on looks alone i would favour the 5050 version as they will provide a nice even illumination to the ping pong ball, the 8mm Led will actually have a hot spot directly in front of the LED.

    Cheers
    Phil
     
  5. jeffrae

    jeffrae Apprentice Elf

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    You can use the tip of your soldering iron to start hole in ball

    I to was looking at using ping pong balls as diffusers

    You can use painter tape with a hole in it as a template stick it to the ball and melt away..

    But have the windows open can be smelly job...

    Jeff
     
  6. OP
    OP
    CRPerryJr

    CRPerryJr New Elf

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    I agree that there could be some issues with structural integrity after you pop a hole in a Ping Pong ball. But I read on another site somewhere that he used an egg carton to help hold the balls while drilling, and that seemed to help. Some sites recommend just using an Exacto knife to cut an X into the ball, and push the pixel through. I've also read about using a soldering iron to burn holes through. But lots of sites say that the materials used to make some of the ping pong balls (Cellulite? Cellulous?) is very flammable. I'll have to try several methods and see which work best.

    I agree that the 5050's are probably the best choice. Just because they are probably brighter and emit light a full 100 degrees. I haven't seen the 8mm myself, but aren't they straw hat LEDs? The primary light comes out from 90 degrees to 120 degrees. That should prevent any hot spots I think. (I'm learning here, so if I'm wrong, please let me know.) One website addresses the hot spot issue on domed LEDs by chopping off a few millimeters off the top of the pixel. I wish I could find the site....

    Thanks all for your help!!!
     
  7. riri7707

    riri7707 Full Time Elf

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    I made some tests with 8mm pixel but the results are not too great:
    As Phil said, you have a point in center due to the led, so the diffusion is not enough good.
    Other factor is where you place the led inside the ball to fill the max diffusion area...

    You will see if you try, the led must to be 1/3 inside to have the better full diffusion

    Other important point is the position between the balls for the matrix, here a full ball doesn't help as you will have mix diffusion between the balls on all sides. Here again the result is not very good, as these 8mm are not enough brightness.

    The best i found was to go to 5050 RGB, but here my tests shows me 1 led is snot enough, specially if you want to see the details far than 20 meters, so i jumped to 3x5050 per ball. The brightness PB was solved.

    Another point is the diffusion and matrix use: here i found the solution to cut the ball in 2 and place the 3 x 5050 symmetric (triangle), and it matches. Great frame, great balanced diffusion ...

    This was the trigger to create my WS2801 PCB 3.5x3.5cm with the 3x 5050 embedded (other topic in the forum), who matches perfectly and can be used with the TP 3212 from Phil.

    Ray propose such strings (see Dmoore topics), but i didn't found them wit 5050RGB and WS embedded at reasonable pricing. This is why i took the decision to develop one.

    For waterproof, i have some ideas, but I'm waiting the first boards to show you how we can build DIY with low pricing.
    Henri
     
  8. OP
    OP
    CRPerryJr

    CRPerryJr New Elf

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    Thanks Henri! That's a lot of good info.
     
  9. dmoore

    dmoore Senior Elf

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    If you are looking for a diffuser, you can use the MegaMatrix:

    http://www.holidaycoro.com/MegaMatrix.asp

    Then you just populate it with either the 3005 pixels, 5050 modules or other suitable LED modules.
     
  10. neilric99

    neilric99 Full Time Elf

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    David, I liked your megamatrix diffuser, but what about something at 2" centers which is what we would use for the RGB pixels
     
  11. OP
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    CRPerryJr

    CRPerryJr New Elf

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    dmoore

    That does look awesome, but is cost prohibitive for me at this moment.

    I'd like to stay under $500.00 for the whole 10*17 matrix if possible. (Better half says I better!!) So far, my cost calculations are as follows:

    Matrix Framework:
    1/2" PVC Pipe 10' (11)=$13.00
    1/2" PVC "T"s (170)=$39.10
    1/2" PVC Elbow (10)=$2.10
    Ping Pong balls (2 Gross)=$30.00
    PVC Cleaner & Cement=(On hand)
    4 wire trailer cable (50')=$50.00
    Various electrical connectors=(On hand)

    Matrix electronics:
    DMX Dongle=$26.00
    TP3212=$36.00
    RGB LED (200)=$180.00 (depending on decided Pixel, this is on the high side)
    Cat5e=(on hand)

    Software:
    LSP 1.7=$89.00

    Total cost=$465.20

    (Shipping and Tax may not be included...)

    !EDIT!
    Oh...Forgot the power supply!!
    5vdc-12amp=$30.00

    New Total cost=$495.20




    Thanks!
     
  12. budude

    budude Way behind schedule - again...

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    You might be able to spray your Ping Pong balls with a plastic-safe, clear, UV resistant spray like this: http://www.tcpglobal.com/spraypaintdepot/uv-resistant-clear.aspx. Check the automotive paints as well as many are made to be plastic safe as well.

    I played with Ping Pong ball lights as well using 4-lead RGB LEDs (not Piranha type). If you sand them down properly to diffuse the light, it looked pretty good - still a touch brighter in the center but not too bad. Some folks discussed this and were looking at filling the balls with silicone/clear caulk to diffuse them - didn't try that but that would have the added benefit of sealing things up.
     
  13. dmoore

    dmoore Senior Elf

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    I think I'd pose the same question - what is the intended purpose for these pixels? Is this for a square matrix?
     
  14. dmoore

    dmoore Senior Elf

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    I guess now I'm not sure what the orginal reason for this thread was. It sounds like you've already developed a "solution" that even incorporates the UV intollerant and crush suseptible ping pong balls you already posted about.

    What you are trying to do was done some time ago - maybe you should contact these folks: http://www.3waylabs.com/projects/mc/
     
  15. neilric99

    neilric99 Full Time Elf

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    my intended purpose is for a 16*25 matrix using 2801 rgb pixel at 2" centers
     

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