Hello,
In your case Rhino is the CAD, Visual Mill is the CAM, Mach2/Linux EMC/many others is the control software, NC (numerical control) is correct also.
Depending on your performance needs, you may be able to use the slower PC to run Mach2 and the router. However, you will soon find out that your maximum speed with steppers or step servos is determined by your maximum pulse rate. Pulse rate is the speed of the step/direction signals coming from your PC control software. Pulse rate is largely based on CPU speed. For example, Mach2 will run in 3 modes, 25khz (demo only), 35khz and 45khz (full version, $150, does all three). However, a slow PC might only be able to run 25khz (25,000 pulses/sec on each axis), while your faster PC might easily run 45khz (45,000 pulses or steps/sec on each axis).
Say you have a high RPM servo with 1000 line quadrature encoder. That would be 4000 pulses/rev quadrature ( rising and falling edge detection on two distinct channels). Now say you have to gear reduce the servo 5 to 1. You now have 4000 pulses/rev of the motor X 5 = 20,000 encoder pulses/rev of the screw. Lets say your screw is 5TPI. Now you have 20,000 X 5 = 100,000 encoder pulses in 1 inch.
With a fast PC, Mach2 can only put out 45,000 pulses per sec, in other words your machine will travel a maximum speed of .45 inches/sec X 60 is 27 inches/min.
You can see how you can quickly use up your pulse rate, and how it can severly limit your speed.
Now lets take a low speed torque servo with a 250 line encoder and 2 to 1 gear reduction. The 250 line encoder is 1000 quadrature X 2 = 2000 pulses /rev of the screw X 5 TPI = 10,000 pulses/inch of table movement. At 45,000 pulses/sec, this system could operate at up to 4.5 inches/sec X 60 = 270IPM.
The Gecko G340 has a pulse multiplier, and Rutex has a multiplier of 1, 4, 10 and 20. This has the effect of moving X pulses for every pulse into the drive (from the PC). In my first example with a count of 100,000 pulses/inch would effectively become 10,000 pulses/inch (as in the second example) by setting the pulse multiplier to 10. The trade off is speed for resolution.
Routers and there size usually need high rapid speeds to be effecient. Try to figure out what rapid speed you want to run your table at and buy your screws, servos etc.. based on what is required to get your desired speed using calculations just like the above, but in the reverse order.
Consider what you want from your design. You may have to use your faster PC to run Mach2 at 45khz. Good luck.  |