Laser cutter Kerf Gauge

thingiverse

This is a design for a laser cut gauge to check your kerf (cut) width. When cutting with any tool, some material is lost. To make components fit together well you need to know how much material is lost. This gauge provides an easy way to measure the kerf. Cut two identical gauges and try to interlock them (start with the zeros matched up) Move them step by step along until the two pieces engage with each other as strongly as you want. Look at the difference between the two numbers (for example if the 0 lines up with the -2 then the difference is 2.) For each point of difference, your kerf is 0.02mm wide. Each notch is narrower by 0.02mm than the one to it's left. Each bump is 0.02mm wider. So the notch marked -5 is 0.1mm narrower than the 0 notch or 9.9mm wide. Likewise the bump marked 5 is 0.1mm wider (10.1mm wide). If a 10.1mm wide bump fits into a 9.9mm wide notch, then you know you have (at least) 0.2mm of kerf. Once you are used to this you can test it at different cut strengths and can set up your cuts so everything meshes just the way you like it. As a bonus feature, the notches in the guide are successively deeper from 2mm to 2.9mm in steps of 0.1mm so you can use it to measure sheet thickness. If you want to play with this some more or to tweak the settings, it was designed on OnShape, and can be accessed at https://cad.onshape.com/documents/729a757effbe5a5d327660b2/w/110ad80925dc22e26d4384d4/e/4903bd0b112da72221b331e0