Instructions 5mm Ply wood or 3/16th if you are in the USA All the holes fixing and mounting holes are for 3mm screws the arduino mounting holes are for standard PC motherboard brass standoffs The Captive nut in the T joint is a 3mm Half nut as they seem to work much better than full nuts for these joints and in the UK you can not get the nice square nuts that everyone seems to use for these t joints. Vector Engrave the violet lines i use 60-80 mms @ 20% power 60W laser Laser cut the Red lines next as these are the holes 9-12 mms @ 90% power 60W laser Laser cut the black lines to finish. 9-12 mms @ 90% power 60W laser http://diy3dprinting.blogspot.co.uk/2015/05/diy-digitizer-with-detailed.html?utm_source=dlvr.it&utm_medium=facebook http://fablab.ruc.dk/diy-digitizer/