Denford Starmill - replacing spindle

[andy_con]

also what does it say on the side of the motor as I'm pretty sure my starmill is 4000 rpm

[uli12us]

What, if you built a special toolholder with small ball bearings they are capable of some 30.000 turns.
In this you have a small spindle with ER11 or so collets.
On the outside you have a small pulley. then you only need a standard motor with a big pulley 10 times the diametre of the small pulley and a belt as link between them.