Aluminum frames

Inspired by other FTIR prototypes I decided to use an aluminum frame. The main reasons for are because its cheap and strong.

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Before actually working on the frame, I made a drawing in AutoCAD. Within this drawing I could easily calculate the amount of IR LED’s I would need and at the same time see how the IR light beams would spread.

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FTIR Prototype Drawing

The local tool shop was friendly enough to cut the aluminum frame (H shaped) into the sizes of my drawing.
So at home I just needed to remove the edges in 45 degrees.

Click the link below to continue reading.

Needed equipment:
– Saw (for aluminum/iron)
– Mitre Block
– Clamp
– Workbench
– Drill
– Drill bits (multiple sizes)
– Punch
– Hand-file

First I mounted the aluminum frame in a Mitre Block. To prevent it from moving during sawing, I used a clamp.
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After sawing, I used a Hand-file to smoothen the edges. It fits nice:
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Next step is drilling holes for the LED’s. Before drilling I used a Punch to make sure the Drill won’t shift during drilling.You could start with a small Drill bit but I just started with 3.5 mm and after that I used 5 mm (which is the size of my LED’s).
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Almost done…
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To keep the parts into place I used a construction like this:
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Next time I’ll cover soldering the LED’s…

2 Comment

    roey

    hello,
    in the drawing you made, doesn’t it need to be symmetrically divided (the LEDs)
    Thanks!

    30 Dec 2007 | Reply

  1. Hello John!

    Wow, this is a really cool and interesting read! I was wondering why the leds are drawn to emit light at an angle like your CAD-drawing shows? Also, are the light emitted by the leds what reflects on your fingers and hence causes infra-red light to be emitted when it bounces off your hand? (the hand changing the wavelength of the photons…)

    It would be awesome if you could reply to my e-mail :).

    Henrik

    18 May 2008 | Reply

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