<html> <body> At 11:46 PM 9/28/2006, you wrote: <blockquote type=cite class=cite cite=""> Thanks, Roger. I had wondered, if a 3" would do it, when I was thinking of using a hole saw. John M. Ross Windsor, Nova Scotia, Canada</blockquote> Hi John,                The 3" works well in most cases, and gives a nice clean result.  You may have to take some extra material from the bottom of the hole  to allow for the extra height of the casters, to correct the pedal height.  This will give a clean flat surface to mount the new flange on virgin wood. In some cases we have had to  increase the depth of the shaft hole. I don't like those cardboard shims as it raises the height of the piano, and leads to pedal complaints.  They also compress and the caster becomes loose. When the shaft hole is too wide in Diameter, we drill them out in a similar manner, and plug them with 1'1/2" dowel.   Glue the dowel in with 5min epoxy. Re drill to the correct size for a snug fit. If the supply house plugs fit, you are ahead of the game, but glue them in. The shaft needs to be snug Drill out and plug the old screw holes,  Drill pilot holes for new screws in a clean area of wood. A note on mounting screws. They need to be wide enough that they fill the flange mounting holes.   The end result will be a good solid mounting that will stand up in School use.  Well! As good as anything stands up in a school situation. The advantage of a Forsner bit over a hole saw.  You end up with a clean flat base to mount the flange. I know.  Forsner bits are expensive.  This is one time a canny Scotsman needs to splurge. :-\ Charge a little extra and do the job right. Regards Roger </body> </html>