Guys

Making a dolls house for the girls xmas. Putting about 10 windows in
it..so made up a nice template from a 9mm offcut of mdf - basically 8
windows about 1 inch square in a row of 4 x 2.

Bought a template bit ( with a bearing at the top of the cutter) and
off I went with my router. I am cutting through 9mm mdf with the bit...

First window went fine..Then noticed as I cut more that the bearing
appeared to be reshaping the mdf template...Suffice to say, after 1
usage some of the template was wonky and cutting curvy window shapes...

Essentially the bearing was routing the edge of the template...I
presume this is the soft MDF..any clues as to what wood to use to avoid
this...Would ply work before I buy a bloody big sheet..

Cheers

Ged