I hate to say this, but I think you are going to continue to struggle with those parts.
The main problem you have is that your motors are rated at 12 volts. For good speed, you want motors rated under 5 volts and preferably closer to 2 volts. Maximum speed is directly proportional to supply voltage, ie double the supply voltage and you double the maximum speed. For good speed you generally want a supply voltage 10 to 20 times the voltage rating of the motor. With a 2 volt motor, that would be 20 to 40 volts. With a 12 volt motor to get equivalent speed would require a 120 to 240 volt supply and that is way too high for most drivers.
The other problem is that when you increase the supply voltage, the current also tries to increase. To use a higher supply voltage than the rating on your motor, you need something to limit the current to keep the motor from burning up. Most modern drives use something called chopping to limit the current, and they will have some way to adjust the current. Can't tell for sure since they don't even list any specs on the web, but your drives don't appear to have this. You could buy power resistors, which was the old way to limit current and there are people still using them.
You could use a 24v or 36v supply and double or triple your maximum speed, but unless your drives have some way to adjust the current you will need to buy and wire in some power resistors which would have to be calculated for your motors and for the supply voltage you end up using.  |