K40 Focus Red Dot Laser Diode Alignment Holder

thingiverse

Here is my simple design for a K40 Focus alignment tool that uses two, 6mm, 5V red dot laser diodes that are very inexpensive and available on Amazon. https://smile.amazon.com/gp/product/B01ITK4PEO/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1 I printed this in eSun PLA+ (also called PLA Pro) and used M3 Hex bolts for the joints and the clamps. The concept is that you set the focus on the K40 to the proper height above the surface to cut or engraved, fire a low power test shot to make a slight mark on the surface and then aim each of the red dot lasers onto that mark so that they converge completely. Now, if the material surface is to low or too high, the red dots will separate. Then you raise or lower the material or, if you have an adjustable head, raise and low it until the two red dots converge. Then you know that the you have the best focus distance without having to measure it. The converged red dots also serve to show where the laser will cut or engrave. This works on stock K40 head, K40 head with an add-on Air Assist, or with many K40 heads that have an adjustable lens height (with or without Air Assist) such as is available from American Photonics. https://american-photonics.myshopify.com/products/k40-16mm-lens-stem-adapter?_pos=9&_sid=d1fe613f5&_ss=r The America Photonics is the head that I have and the red dot lasers are clamped to the moving part of the adjustable lens so I just move the lens up or down until the red dots converge. 11/21/20 Added V2 of main body in order to get the lasers higher on adjustable focus lens so the dual lasers don't collide with the frame.