Q1 when machine is powered up and no cade has been comanded should the the steppers produce a hissing sound
very simmilar to an air leak from a compressor and should the steppers have any holding torque at that instance.
Yes it its quite normal for steppers to make a noise when sitting still, some drives make things quieter than others but the main thing is that your motors dont get too hot to touch. Yes the steppers should have their holding torque as soon as they are powered whether moving or not.
Q2 what would be the effects on the system if the power supply did not run a bleed resistor across the caps.
Dont have a bleed resistor on my mill and never had a problem.
Q3 why does mach3 constantly keep tripping a reset after half a dozen lines of code when running a program, reset and it,s
good for another dozzen lines.
Sounds like you have noise in your limit switches, try going to generalĀ config and setting the debounce up a bit, try 2000 and if it helps then try lowering until you start getting problems again.
Also run the drivetest.exe (in Mach folder) and check that the line is fairly smooth with no huge spikes.
Q4 when running the roadrunner program and it runs to the end of the last line of gcode, should'nt the machine return to home automaticlly or do you have to command it home, and if so what is the gcode command to home all axis.
This depends on what you are meaning by home, normally the homing or referencing of the machine is done at start up and thats it until the next time you start the machine. Once referenced you can then jog to any position on the table and zero the axis and this will be your work offset. If you press the Go To Zero button the machine will go to the X, Y, Z, A zero position. If you want the machine to go to the zero position when it finishes the code just put a line or two of G Code in to do that, normally you would raise your Z axis first then the next line would take the rest of your axis to your zero position.
Also worth mentioning is you may want to set a safe Z height so that when you press Go to Zero button the Z will move up to your safe Z first then the X and Y will move to zero and then finally the Z will move down to zero.
Hood