I wrote software to draw precision sprockets and gears, both modified and standard. I am retired from Kenmore Gear where I was Engineering Mngr. for 30 years and I'm an expert with involute profiles. I have provided the sprocket drawings for the precision required to NC Racing in Pennsylvania as well as many companies in the Ohio area. I provide DXF and DWG files for waterjet, EDM and laser machines. While I may lag behind in many areas and you may find those of equal ability, there simply are none that are better at this than I am. Best regards; Ray Doll