Workshop Tips and Tricks
- Bulk holesaw enlargement. If you want to enlarge a hole saw hole - double mount a hole saw on the same holder! . Problem - larger hole saw has nothing to hold to. Solution - smaller hole saw used as a guide. Another good one - use a plug inserted onto the guide drill . Another - inferior solution - make a guide . May work in cases where you can't double-mount a hole saw. Another inferior solution - glue the plug back in .
- Accurate enlargement of small holes - sandpaper on a dowel - 
- Semiaccurate enlargement of large holes - wood burr , wood-shapind dish for grinder . Use grinder with a cylindrical wheel. . DIY - a metal gear used as a grinder. . Or mini saw blades come in 3-4" size or smaller. . Round file in a drill bit. . Rasp . Linear rasp . Rasps are faster than files