Message text written by INTERNET:[email protected] >Perhaps the only way to get a truly 'burr-free' and 'surrounding depression free' hole is to chemically etch it.<
Not sure this message of mine is really relevant to those making shadow sharpeners where the hole size might need to be larger than half a mm. However, a pinhole camera enthusiast suggests using 50 micro metre (two 'thou' in the UK) brass shim as the material for the hole and, with it resting on some corrugated cardboard, tapping a sharp 0.5mm sewing needle through the shim then rotating the needle bewteen finger and thumb to ream the hole and finally rubbing both sides of the brass shim with fine emery cloth. I haven't tried this myself but it is said you can use this technique for even smaller holes... Hmmm Tony, do you think it would work for 1.5 -2mm holes? Patrick ------------------------------------------------------------------------- E-Mail: [EMAIL PROTECTED] Web: http://ourworld.compuserve.com/homepages/Patrick_Powers/ Lat: N 51d. 49m. 09s: Long: W 00d. 21m. 53s -
