Best RGB Pixel for a Ping Pong ball

CRPerryJr

New elf
Joined
Sep 14, 2010
Messages
21
Location
Argentine, MI
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?
 

Attachments

neilric99

Full time elf
Joined
May 20, 2010
Messages
295
Location
Irvine, the OC, CA
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.
 

CRPerryJr

New elf
Joined
Sep 14, 2010
Messages
21
Location
Argentine, MI
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.)
 

AussiePhil

Dedicated elf
Administrator
Joined
Jun 20, 2009
Messages
1,386
Location
Canberra, ACT, Australia
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
 

jeffrae

Apprentice elf
Joined
Jun 2, 2010
Messages
60
Location
Linville
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
 

CRPerryJr

New elf
Joined
Sep 14, 2010
Messages
21
Location
Argentine, MI
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!!!
 

riri7707

Full time elf
Joined
May 9, 2010
Messages
222
Location
Paris / France
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
 

CRPerryJr

New elf
Joined
Sep 14, 2010
Messages
21
Location
Argentine, MI
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!
 

budude

Way behind schedule - again...
Joined
May 13, 2010
Messages
127
Location
San Jose, CA
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.
 

dmoore

Senior elf
Joined
Apr 26, 2010
Messages
586
Location
Houston, TX, USA
neil said:
dmoore said:
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.
David, I liked your megamatrix diffuser, but what about something at 2" centers which is what we would use for the RGB pixels
I think I'd pose the same question - what is the intended purpose for these pixels? Is this for a square matrix?
 

dmoore

Senior elf
Joined
Apr 26, 2010
Messages
586
Location
Houston, TX, USA
CRPerryJr said:
That does look awesome, but is cost prohibitive for me at this moment.
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/
 

neilric99

Full time elf
Joined
May 20, 2010
Messages
295
Location
Irvine, the OC, CA
dmoore said:
neil said:
dmoore said:
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.
David, I liked your megamatrix diffuser, but what about something at 2" centers which is what we would use for the RGB pixels
I think I'd pose the same question - what is the intended purpose for these pixels? Is this for a square matrix?
my intended purpose is for a 16*25 matrix using 2801 rgb pixel at 2" centers
 
Top