Just spent a few minutes watching the Video's, I hadn't seen these before. Thank you.
The 1st doesn't so much apply to me at this stage as I have the combined board but will be useful if (when) I get separate drivers and a BOB. The second video was very helpful and have followed along and all my Drives (apart from my dead Y..) seem to do what they should.. so I feel the Pin No.s I have are correct.. yay

Thanks Neale for your comments about the heat, I have now taken to spitting on the motors to keep them cool.. Do I need to spit on the PSU too..? Bzzzt
I am taking this to mean that whilst a program is running and a particular motor may be stationary it is not idle.. ie.. it is powered to maintain that position and will be making some sort of noise rather like revving a car engine in a gear on a hill to maintain ... blah.. Like, riding the clutch..! (I'll get there eventually..)
Does 'Tuning the Motor' seems to help with this heat problem though..?

At the end of the 2nd Video a tantalising reference to slaving Motors.. But.. (I thought it would be quite a common practice.)
I am assuming that the slaving has to happen in Mach3 prior to the driver boards so the same signal is going out to 2 drivers but the actual Motors have 2 wires reversed (on one motor) to allow mirror action..? Sounds straightforward..
Thanks again