Hi,

so theres no more speed to it.

That spindle is a brushed DC motor using permanent field magnets. The top speed is determined by the BackEMF of the motor
which is a fundamental property of the motor's physical construction, field strength and number of turns on the armature.

The only way you can make that spindle go faster is to use a higher voltage, and probably run the risk of damaging it due to
excess currents at start-up and/or shut-down. Additionally that spindle uses single row ball bearings in the 60 series. They are
not known for their highspeed/low runout properties. Almost all highspeed spindles use angular contact bearings and all good spindles
use P4/ABEC-7 grade angular contact bearing matched pairs.

If you need/want more spindle speed then you should look on EBay where there are hundreds of asynchronous spindles up to 24000 rpm
with VFDs of up to 400Hz. Chinese manufactuerers compete on price and we as consumers benefit because of the low prices offered.
Quality is a somewhat larger question......but most users report pretty good results.

Craig