OMTech 60 W Laser: COB LED Shades

Adding LED strips around the interior of the laser platform definitely improved the visibility of things on the honeycomb platform:

OMTech 60W laser - COB LED strips
OMTech 60W laser – COB LED strips

However, all that upward-directed light goes directly into my glare-sensitive eyeballs, so I added shades above the strips:

COB LED Shade - installed
COB LED Shade – installed

They’re cut from corrugated cardboard because I have an essentially infinite supply and I’m still working out speeds and intensities. Eventually they’ll become something like black acrylic.

The brackets emerged from the vasty digital deep through the miracle of 3D printing:

COB LED Shade Brackets - slice preview
COB LED Shade Brackets – slice preview

They’re stuck to the laser cabinet and the cardboard with double-sided duct tape. If you’re careful, they will line up along one edge of the tape, roll over neatly to stick their other face, then a single razor knife cut can separate each pair of neighbors.

The underside sports an aluminized mylar strip to redirect the wasted light in a more useful direction:

COB LED Shade - aluminized Mylar reflector
COB LED Shade – aluminized Mylar reflector

The tapeless sticky shipped with the laser holds the reflector in place, while its 20 mm width sets the 21 mm shade dimension. Although you want a reasonably smooth layer, it need not be mirror-flat.

Now it’s really bright in there:

COB LED Shade - overview
COB LED Shade – overview

While I had my head under the hood, I stuck a fourth strip of COB LEDs on the lip along the rear edge of the opening; it’s bright enough to cast the shadow just forward of the laser head despite the OEM under-gantry LED strip. Because the rear strip is aimed downward, it didn’t need a shade.

The perforated cardboard sheet on the left is a spike plate: more about that later.

The SVG drawings as a GitHub Gist:

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The OpenSCAD source code as a GitHub Gist:

// Bracket for COB LED shade
// Ed Nisley KE4ZNU 2022-03-24
BaseLength = 20.0;
/* [Hidden] */
ThreadThick = 0.25;
ThreadWidth = 0.40;
HoleWindage = 0.2;
Protrusion = 0.1; // make holes end cleanly
WebThick = 4*ThreadWidth;
BasePlate = [BaseLength,5*WebThick,WebThick];
//----------
// Create parts
module Bracket() {
R = BaseLength/3;
N = 36;
union() {
rotate([90,0,0])
translate([0,0,-WebThick/2])
linear_extrude(height=WebThick,convexity=2)
difference() {
intersection() {
union () {
square(2*R,center=false);
translate([0,2*R])
rotate(180/N)
circle(r=R,$fn=N);
translate([2*R,0])
rotate(180/N)
circle(r=R,$fn=N);
}
square(3*R,center=false);
}
translate([2*R*cos(180/N),2*R*cos(180/N)])
rotate(180/N)
circle(r=R,$fn=N);
}
rotate([0,-90,0])
translate([0,-BasePlate.y/2,-BasePlate.z])
cube(BasePlate,center=false);
translate([0,-BasePlate.y/2,0])
cube(BasePlate,center=false);
}
}
//----------
// Build them
Bracket();

4 thoughts on “OMTech 60 W Laser: COB LED Shades

  1. Adding some pseudo rivet heads on the brackets would make them look just like the ones Harrison Ford was hanging onto in Blade Runner.

    But I’m sure pointing out this detail would get the same sort of blank looks I got when I baked a banana bread loaf for a birthday party and indicated that I put the age of my sister-in-law in binary on top of the loaf, banana slices being zeros and icing strokes being ones.

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