Hi, a few thing that will increase the speed:
Lower the selfinduction of your steppermotors
: If you have steppermotors with 8 leads, you can place the coils in series or Parallel. When you place them in series, the selfinductance will be doubled... when you place them parallel you will half the selfinductance... What does this mean and what are the pro's and contra's..
Selfinductance will create a voltage while rotating.. The faster you go the higher the voltage.. If you supply only 24V and the inducted voltage is 20V there will only be 4V left to let a current flow.. Current is torque.. You want a higher torque at higher RPM's so you have to increase the supply-voltage and decrease the selfinductance.
A contra of parallel is that you need twice the current.. your supply must be able to deliver that.
Use better cables.. A lot of energy is lost in cheap, thin cables and connectors. Keep your wires as short as possible and use appropriate cables.
Think of buying good stepperdrivers. Leadshine's or clones or Gecko's make a lot of difference in speed over most of the lowcost driver-IC's When you buy them, take as high working voltage as you want to pay.. also replace the powersupply.. (maybe you need to buy a small separate supply for the controller..)
You can increase the current as long as you can hold the steppermotors for a few seconds (ie not hotter than 60 degrees C) after a quarter of an hour moving.. Many stepperdrivers reduce the current to 50% after 1 sec standstill
Ofcourse your steppers must be powerfull enough and friction must be low..
Kees