What do you get when you add one Arduino, some shift registers, a few transistors and a handful of LED's to somebody with way too much time on his hands?
The simple answer is Another board of many ping pong balls!

Although this is not completed yet, read on to find out why....
But to give you a head start I thought I would show you where I am at and give tips where I can.

This was inspired when The Much Larger Board of Many Ping-Pong Balls by DaShroom was featured on the main page of instructables.

The only problem I had, like many others who frequent this site is that I didn't have a laser cutter to hand, I do have a CNC that I but many years ago but that has a small bed so this would end up as a small scale replica, and one thing I don't do is small scale!
So rather than try and show this as a new idea I am trying to help make this available to the masses by showing some "alternative" short cuts and how to's.

I looked at various options, polycarbonate triple wall sheets because they are very light and quite rigid but the wrong stock size and then rather expensive once you get the correct size, the other issue here is if you try and use 25 or 35 mm polycarbonate to hold the LED's and act as a diffuser you end up with the light diffused only in the vertical strips. You would have to adjust your spread from 40 mm to around 10 mm. I called in to a local supplier and once I explained what I was doing they gave me some offcuts to experiment with. Very nice people and well worth a mention at Nick Gray Plastics if you need any sheets.

PCB sheets with the tracks cut in like they used on the Solderlab site, looked very expensive and I could not find a local supplier that did anything near big enough, I even looked at using small panels that could be bolted together, the problem there is stability once you assemble the unit, then it becomes too heavy with all of the stiffening bits in place.

The simple answer (for me) was a trip to B&Q and to buy one pack of end of line laminate flooring for just under £10, then use some flat softwood to build a frame. I used glue to assemble the base so it was good and solid then spent some time making a template for the holes. It is worth spending the time because if the template is wrong so is the finished article.

I used 5mm LED's so to give a clean hole I drilled everything through the template with a 4mm bit, then once they were all done I opened them up with a nice sharp 5mm bit. Its worth noting that I had to keep changing the bit because they went dull quite quickly. On the back side I used a standard countersink on each hole to ensure that the LED protruded from the front by around 4 - 5mm.

Step 1: Tracks and crossed wires

The next obstacle was the tracks, this is where 5mm self adhesive copper tape came to the rescue. You can get this off eBay if you just have a quick search. This stuff is very useful for a lot of other little projects too but back to this one....

Once all of the holes were drilled I could start to lay down some tracks, three vertical and one horizontal per LED.
Or 24 vertical and 8 horizontal per segment, or 192 vertical and 64 vertical for the entire display.
That equates to around 103 meters of coper tape needed. (plus a bit for when you drop it on the floor)

If you lay down the vertical ones first then put a row of insulation tape over the top you can lay the horizontal ones right over the top of the tape.

A couple of things I learnt the hard way and hopefully will save you time:
1, when you pull off the insulation tape wait a few seconds before you stick it down, when you pull it off the roll it will stretch and over time it will shrink back down to its normal size, this will cause shorts later on and they are a right pain to sort out after the event let alone find!
2, do NOT do a solder joint where the two tracks cross, there are plenty of other places to solder so keep clear. The insulation tape melts and you get a high resistance joint between the two tracks, just enough to stop the pretty lights from working.

Take your time!

I found that if you can't wait for it to settle just put one length of tape over the tracks then cut between the gaps, it will shrink but not anywhere important.

Use some small bits of coper tape as solder tabs for the resistors as shown in the pictures.
<p>I made Simple interactive ping pong game</p><p><a href="http://www.instructables.com/id/Free-Interactive-Projection-Pong-game-Water-effect/" rel="nofollow">http://www.instructables.com/id/Free-Interactive-Projection-Pong-game-Water-effect/ </a></p>
Excellent build! I'm assuming the resistors on the matrix are led specific, but what are the values for the pcbs? DaShroom's site is down at the moment :-)
dashroom66.com is down, but will be back up in soon, <br>my non-commercial blog with projects is online at dshroom66.org <br> <br>:-)
Shameless plug there! <br>You forgot a bit there www.dashroom66.org <br> <br>Now you got me plugging your site!
Haha :-D
Hi,<br><br>Yes, the ones on the matrix were specific to the LED's, however the supplier gives you the resistors based on your supply voltage, I think they simply have an abundance of 510k because they sent them for all colours at 5V and 12V! The 8 resistors on the PCB's that feed the transistors are 1k.<br><br>Regards<br><br>Darren<br>
Nice project :-D <br>Glad to see that it all went ok :-) <br> <br>Just incase there is any confusion, my kits and solderlab's kits are not the same or compatible with each other. However, you can use a modification of the solderlabs controller with my kits if you want to use their firmware (and apparently I haven't uploaded mine, so you don't have much choice :-P) <br> <br> <br>Great instructable btw (love the copper tracks) :-D
Very interesting project and a nice alternative to solderlabs' LED boards. :)
Thank you!<br><br>I try and use things I have around to get the same end result, sometimes it works and other times.... well :-)<br><br>
By the way, where did you get all those ping pong balls? :)
I have also added more information and a hyper link in the balls section.
I got mine from Sports Directory UK <br> <br>http://www.sportsdirectoryuk.co.uk/product/bulk_gross_table_tennis_balls_white_(per_144) <br> <br>(I have noticed the price has come down, I wonder if that is to do with an increased in demand?)
would it look any better/worse to use colored ping pong balls?
The light emitted would be filtered depending on the colour of your balls, if you want true RGB you would need to use a neutral colour like white.
I appreciate the info! I've been wanting to get into making <a href="http://www.topmade.com/signsandservices.php" rel="nofollow">signs in Calgary</a>, and its stuff like this I wanna make. Thanks a ton for sharing!
How much would it cost on average ?
Now that all depends on how you want to do it,<br>The cheapest way to build one of these would be to buy all of the parts yourself and either make the PCB's yourself or use breadboard.<br>There are no exact lists anywhere for all of the parts but I can give you components and quantities to help you along.<br>I bought 1000 RGB LED's for this and other little projects that cost me &pound;116, the kit from Dashroom cost about another &pound;164 and the ping pong balls are &pound;24 per box of 144.Wood for the frame and other bits etc...<br><br>So this one cost around &pound;400<br>Plus the Arduino, and the power supply :-(<br><br>Come to think about it, this was quite an expensive project!<br>If you cut out all of the niceties and solder directly to the breadboard and use stranded cable to link it all together you can bring the price down a bit.<br><br>But we don't do things like this for the money, we do it for the love of creating stuff.<br><br>(that's what I am telling the bank manager anyway!)

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Bio: I build therefore I am.
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