Computer Fan Marking Templets

I needed an accurate way to layout and locate modern sized fans on a retro case that I am building in. This was my solution. 

There are various options for templets, 120mm, 140mm and dual mounting 120mm/140mm.

Some have 1/8th inch holes to either use for center punching or drilling with a pilot drill. 

Others have standard sized fan screw holes. So you can screw them down using existing holes. 

The ones with circular inner rings are so you have a physical representation of how how big the fan hole should be for a standard 140mm fan. 

Tips. 

• Scale Z height, make sure its just Z, to increase thickness if using the ones for screw holes. Other wise the screws don't have much to grab. 
   
• Tape everything down if you don't have existing holes. Make your punch marks carefully, so as to not deform the plastic templet. Then remove the templets to drill. 
   
• A 5 inch bi-metal hole saw is just a tiny bit smaller then the 'proper' sized hole for the 140mm fan. Just go really slow, use cutting fluid. Clamp the daylights out of the thing your drilling and put a wooden waste board behind the metal if its thin.