[techhelpbb]

The Arduino is adequately ample to do what you want.
You can usually get a Mega2560 from MicroCenter for about $10.
The Mega2560 is capable of running a 3D printer with a RAMPS 1.4 shield to set expections.

Either using some of the many FRC related projects or just bit smashing on your own.
The only place you might find a bit tricky is around encoders.
If you do that look for ICs to count the rotations or a dirt cheap Xilinx or Altera FPGA development board.

If you want to take that up a notch use an Arduino Yun and that will give you WiFi.