Sorry to change the subject lads, one for Boskonay and Anto regarding the kadee uncouplers...
I got some of the 3mm cube magnets but I'm having trouble getting them to work reliably. Like yourselves I placing them 4 in a row between the sleepers, but polarity-wise which way do you have them facing? I also think I may have them a little low, I have them sitting on the underlay and I'm using code 100 track so I reckon I might need to shim them.
Any tips?