Finney A3 American pick up issues can anyone help.

[Simon Moore]

I've had a finney A3 in for repairs built by Chris Wesson & it has that silly American pick up system which is driving me barmy.

 

I wI'll try to explain what's going on. When have a large 6ft 9inch radius circle of track to test locos on & if the boiler is facing 1 way on the track it runs without issue both forwards & backwards. If I turn it round with the boiler facing the opposite way it sparks on the front bogie & when I take the bogie off it still shorts out. I pulled the tender so the body & tender were not in contact & it still died. The draw bar has a isolation using a paxoline washer. It's driving me nuts because I cannot solve the problem.

[Horsetan]

The only thing I can suggest is running it dead slow in the direction where the shorts happen. On each short, does it look like the wheel shorting strips have lost contact?

 

I don't think there's anything wrong with the American concept, but it does require things like wheel-shorting strips to stay in place, and insulation to keep on insulating.

[Grovenor]

If its the front bogie then the problem is the wheels on the insulated side of the loco touching something on the chassis which is connected to the other rail, run in the dark you should be able to see where the sparks are. When its the other way on the track contact doesn't matter as the wheels on the other side are at the same polarity as the chassis.

Not specifically an American pickup problem, same thing was common when the norm was to have chassis live to one rail and only have pickup wipers on the other side.

Regards

[Simon Moore]

Cheers for the comments I think ive found anothe potential short which is causing the issues. I have a plan to tackle both.