[mugabe]

Does somebody mind to share maximum radial and axial forces to be experienced during marble and stone engraving ?

[Egar Twins]

try to find a belt driven spindle that holds at least 10000 RPM you will never use it over 8000 for stone but overgun it so you are not maxing out...you will need a sealed high speed bearing...sks has a fine selection for any application. Dont feed at greater then 4 inches a minute when plunging/engraving and spin at high RPMs between 7000 and 10000 depending on the tool....you will find that an engaving bit is only as strong as the speed you spin it....load should read no more then about 8%