Thursday, 12 June, 2008 § 2 Comments
Hey guys/gals sorry for the lack of posts…. i’ve just been busy with the project and various other things. lets get on to the IR frame. The IR frame is constructed using an aluminum U channel, bought from homedeopt.
sorry for the blurry picture ( i have bad lighting to blame)
Any way…. i measured my appropriate lengths on U channel and marked them out using a sharpie.
To reduce the hassle of securing the aluminum in the end rather than cutting the entire joint i cut it half way and removed the side rails.
now this V’ shape can easily be bent note the aluminum U channel i purchased was made of roled continuous casting as such the material is ridged, however since aluminum is soft it will give way easily but if you try to bend with out applying heat it will crack and break. So my advice is obtain a butane torch any lighter with a blue flame. And apply heat to the corner.
NOTE: ALUMINUM GETS EXTREMELY HOT VERY QUICKLY WEAR PROTECTIVE GLOVES…
As you are applying the heat gently apply force and slowly bend the corner to form 90 degrees.
Then using Aluminum tape secure the entire tape any corners that have any gaps. this will ensure that no IR escapes from the frame.
After making the frame place the IR array in to the U channel and apply small tacks of hot glue using a glue gun to ensure that the IR lights stay at a constant angle angle and don’t move around in the frame.
Once you have all the IR place in the frame it should look some thing such as this.
Next take your polished acrylic sheet and place it within the frame… mine was a tight fit. Then using Aluminum tape tape the edge of the frame and around 2cm of the acrylic sheet together. You will need 2 layers of tape since the IR light is very strong near the edge. Tape off all 4 side.
your final IR frame and screen will look as such
Now its time to test your setup…. Mine produced really bright blobs under normal ambient lighting conditions. However what i’ve noticed is that the camera is very sensitive to natural light. As such the photo negatives will have to be replaced by a professional IR band pass filter later on, in the final build.
Some test results under normal lights…