Quote Originally Posted by Voicecoil View Post
You could look at a Chinese spindle that has better torque low down (likely a 4 pole motor), these are sometimes called "constant power" spindles when they have torque that drops off linearly with RPM.
You can do that with any induction motor, as it's what happens when you run out of volts to drive the motor at the intended speed. It is however actually a good way to maximise low speed torque, while still getting a high speed, as you're not as likely to need full torque at higher speeds for a low of machines.

The problem is, you can't break the basic rules of physics.
If a motor coil is rated to handle 5A, you might be able to push a bit more current through it, but push too much and it'll melt. It doesn't matter what voltage you use, if the rotor stalls, it'll likely melt.
And as Torque is direct result of current, you can't magic up more torque without pushing more current.