Tuesday, April 19, 2011

A new kind of baffles

It started as a challenge, then it became an obsession: the baffles for my own version (still work in progress) of Word Clock, the grid that separates the LEDs from one another, so that every letter on top of a LED can be lit individually.

Baffles for Word Clock clones have been made before, see here and here (part of this and that instructables, respectively). These examples separate groups of LEDs rather than each individual LED. Justin and Anool of ClockTHREE fame raised the bar (they did not call it ClockTHREE for nothing :) with their individually addressable LEDs and the associated baffles, an elegant and remarkable solution, nicely integrated with the board and the case. Trying to replicate their results for just one prototype is both expensive (laser-cutting) and tedious (calculations, drawings, assembly). After a lot of thinking, I "invented" my own solution for the baffles, as shown in the photo below.

Basically, I used 40-pin female headers to separate the low-profile, wide-angle, LEDs. The headers are held in place by soldering them to the prototyping board. For the 8x14 LED matrix, I used about 40 headers, for a cost of about $12.

Generally speaking, designing and making the baffles is a feat. With so many choices, one needs to answer a few questions before designing them:
  • what material should be used (cardboard, plastic, wood etc)?
  • what manufacturing process would be the most appropriate (in terms of price, assembly time etc)?
  • how could they be attached to the board?

Plastic is an obvious choice for the material:
  • laser-cut (expensive, requires the assembly of the parts);
  • mold-injected (perfect for mass-production; no assembly required: what you get is what you use);
  • 3D printed (suitable only for prototyping; may be expensive).

Even after having the baffles made, the question of how to attach them to the board still remains. They need to be placed equidistant between the LEDs and held solidly in place (screwed down to the board maybe?).

Now you don't need to wonder anymore why Peggy 2 does not come with baffles :)

1 comment:

  1. Wow, cool. This will look great with a painted faceplate!