Atlas GP-9 slipping

[chuck geiger]

I've added two new cars to the roster on the layout. With 4 of the 6 original cars and the new
cars, the loco is slipping and spinning in place after it completes a turn. If I speed up the
throttle, it goes through. If I put another unit on it, it's fine. I wonder if this is because I
use Wahl clipper oil? Advise is welcome.

[jpwisc]

Try cleaning the tops of the rails and the loco wheels with 70% Isopropyl and then run the same section again. That will tell you if it is the oil causing the slippage.

What types of wheels are you running on the new cars?

[chuck geiger]

THAT WORKED. New cars are metal and others are plastic, gonna switch everything to metal.

[jpwisc]

If you have the right axle lengths, freight cars with metal wheels pull effortlessly. It is an easy conversion that pays big dividends.

[Nick Lorusso]

Was this on a grade? Also I use the the method of 2 cars per powered axle... i.e. 4 axle GP= 8 cars 6 axle SD = 12 cars.