I put blu tak to line as well as brace the trunk on the metal. Seems to work.
Also the newton ball problem, to me it sounds like the wire actuator on the switch the other ball rolls over may be too high/proud and a slow returning ball may not pass it. Try adjusting the actuator height. I have similar problem on the TZ skill shot which is exactly that problem
Thanks mate. Will have a look as it stops half way up? Still have to have you over for a game btw, haven't forgotten