SPARKING LOCOS

Dirty tracks, dirty and/or pitted pickups, and dirty motors can all contribute to excessive sparking. However, some minimal sparking is just plain normal, especially with the higher current AC motors.

Like Bob says, it's normal to see some sparks for AC motors, they draw more current than the can motors most modern stuff uses.  Even after I've cleaned everything up, my AC motored stuff still has some sparks on the pickups and even on the wheels.  That's with track that's whistle-clean as well as a currently maintained engine.

In a chicken-or-the-egg type question, does pitting cause sparks, or does excessive sparking cause pitting? What does cause pitting in some electrical bits?

Enquiring minds...

PD

Thanks for the info guys .. appreciate it!   Just wasn't used to seeing Sparks fly!

People have gotten so used to modern engines with low current and DC motors that they forgot what postwar stuff looked like running.

@pd posted:

In a chicken-or-the-egg type question, does pitting cause sparks, or does excessive sparking cause pitting? What does cause pitting in some electrical bits?

Enquiring minds...

PD

My understanding is this> Electrical Pitting is caused whenever there is poorish conductivity between two adjacent surfaces and by the removal of an electric current at a given location (one conductor rolling along another). Pick-up rollers are fair conductors but not perfect at higher currents such as are drawn by postwar AC motors.

The arc (electric current passing through a minuscule or larger air gap) causes pitting.

Carbon-dioxide molecules are atomized by the arc as oxygen burns off from the air.  The residual hot carbon is mostly what leaves a black residue on the rails.

If I am mistaken, hopefully someone will be nice enough to correct me...

Thanks for that. So it sounds like dirt/oxidation can cause the excessive sparking, which then contributes to pitting of the adjacent surfaces. Presumably keeping the electrical contact surfaces clean will reduce sparking and the possibility of pitting.

Makes sense. I run prewar gear predominantly and I haven't noticed much in the way of pitting (or excessive sparking). I am, however, guilty of running stuff until it's absolutely filthy, so I likely need to do a better job of keeping rollers/shoes and rails clean.

PD

I'd be curious to see how bad the sparking is Rex if you can manage a video clip...