I am working on building a CNC mini mill using surplus components. I have some NEMA 34 unipolar motors that I feel will provide enough power to drive this machine (slowly). I will be using TurboCnc on an old PC driving a very simple phase driver using TIP120's. I am being careful to keep the maximum draw to 4amps since the transistors are limited to 5amps. I built a linear power supply that should provide enough current for this setup. My phase driver is built around this basic design:
SIMPLE PHASE DRIVER
My problem is, why is the discrete driver in these forums so complicated ? Since it is not a chopper ? I am just wondering because I do eventually want to move on to a better and faster machine with better drivers. I am a little confused with all the different designs floating around here, and I feel that my best choice is to just buy Gecko Drives when the time comes. I think that the speeds that these chopper drives achieve are awesome ! I think that the fastest I can crank out is about 11 ipm using a 1/2-10 acme screw.
It would be nice to find a simple chopper design that is a little dumbed down for a beginner like me (the designs I have seen here still blow me away) Just because I like the satisfaction of building something myself.
Right now, the best I can hope for is to mill new simple driver PCBs when my machine is ready, so I can use IRFZ44 and not worry so much about the current.
Also, some microstepping drives say that they can handle 3 - 4 amps, that doesn't seem very powerful to me. What am I missing ?
Can somebody with more experience give me some insight about this ?