Ultra Cheap laser line pointer - laser level

thingiverse

I\'m in the process of building a MakerScanner, but ran into the problem that the laser line proyector I have is quite big and I didn\'t wan\'t to take it appart. Also didn\'t want to buy another one as they are expensive at the hardware store and I wanted to see if I could make one as cheap as possible by modifying a cheap red laser pointer from the dollar store. It turns out it was really easy to do and only needed a laser pointer and a small piece of a plastic fresnel lens. Instructions The first you\'ll need is a laser pointer. I used one from the dollar store (2$CAD). This laser is one of those that come with different head caps that have small pieces of acrylic with etched funny drawings in them (happy faces, hearts, etc) that get projected on the wall by the laser pointer. I though it just be a matter of changing that piece of acrylic for another one with a line etched (with a cutter) on it at it would work.. well that didn\'t work so well so I started trying different materials and found by accident by lighting the corner of a plastic fresnel lens that I had sitting on my desk that it produced and incredible nice an perfect line! so.. The second thing you\'ll need is a plastic fresnel lens (1$ CAD), I had a couple of those of different sizes that I got from the dollar store for other projects. The one that worked the best was one that is roughly the size of a letter sheet of paper. Once you have your fresnel lens take one of the laser caps with figures and mark a corner of the fresnel by putting the cap on it and drawing around it with a marker. It has to be the corner of the fresnel as it has more parallel lines than towards the center, the more you go towards the center the projected line becomes smaller until it is just a point at the center. Once you mark the shape of the lens on the corner of the lens, just cut it a bit smaller than the mark so it fits inside the cap. After cutting the piece, take out the original acrylic piece from the cap and put the piece of fresnel inside. Which side of the lens points towards the outside doesn\'t matter much, though I noticed that placing the piece with the smooth part towards the laser and the bumpy part towards the outside gives a slightly brigther and smoother line. Put the cap on your laser pointer, and voila! you are done! now you have a really nice and cheap line laser pointer. (next thing to do modify the laser pointer to be powered from a USB port).