Anyone know how to lock the distance between price bars and the right hand side ruler?

Move the chart to the amount of space you would like between the last bar the the right border;

Right Click in your chart -> Chart Settings -> Advanced Settings Tab -> Tick the option called "Lock Fill Space".

Just be sure to keep an eye on the green 'End of Chart' indicator in the bottom right corner of the app (I don't remember the exact name of it) ... if not, you might 'think' you're at the hard right edge, but your not.
Not that it's ever happened to me

LDog 

Just be sure to keep an eye on the green 'End of Chart' indicator in the bottom right corner of the app (I don't remember the exact name of it) ... if not, you might 'think' you're at the hard right edge, but your not. Not that it's ever happened to me

Haha I've done that before. I sat there wondering wtf was going and why the market had stopped for the past hour. seriously it took me that long to notice

Just to prevent that you don't see the actual price, you could set the Current Price line to Display Current Price on Chart Bars to Yes.