Melted Wheel Pickup

[electricity_bill]

Hello

I was cleaning the wheels on my LGB Rio Grande ALCO (similar to 20550/25552) when I thought that I has a missing wheel pickup. On taking the base plate off, I can see that it is not missing, it has melted into the bogie casing as per the picture. Anyone experienced this before and what could have caused it?

 

[PhilP]

Yes, seen similar..
Either the skate was 'hooked-up' and other wheels were not picking-up (dirty wheel-backs, or worn carbon-brushes) on that side, or more likely, loco not on track properly, or derailed and only that wheel picking-up one side.

A right-royal pain to dig the brush out of the block.. Then had to build-up the block to support the replacement brush.

 

[Neil Robinson]

Yes, seen similar..
Either the skate was 'hooked-up' and other wheels were not picking-up (dirty wheel-backs, or worn carbon-brushes) on that side, or more likely, loco not on track properly, or derailed and only that wheel picking-up one side.

A right-royal pain to dig the brush out of the block.. Then had to build-up the block to support the replacement brush.

I've noticed that this and weak springs inside the pickups (also presumably due to overheating) often occurs in twin bogie locos. I assume it is often caused by one or more wheels of a derailed bogie ending up on the "wrong" rail thereby causing a short circuit through the pickups and loco wiring. Stalling on an incorrectly set live frog point is another cause I've noted.

 

[electricity_bill]

Yes, seen similar..
Either the skate was 'hooked-up' and other wheels were not picking-up (dirty wheel-backs, or worn carbon-brushes) on that side, or more likely, loco not on track properly, or derailed and only that wheel picking-up one side.

A right-royal pain to dig the brush out of the block.. Then had to build-up the block to support the replacement brush.

How did you manage to get the melted pickup out?

 

[PhilP]

How did you manage to get the melted pickup out?

Cut some of the 'melt' away, then used the soldering iron to heat the brush-holder, and prised it out with a small screwdriver..
Not pretty, or easy.. - BEWARE! the brush-holder stay hot for a surprisingly long time!

 

[Neil Robinson]

. - BEWARE! the brush-holder stay hot for a surprisingly long time!

How do you know this?

 

[Dan]

I use a small reamer and file to clean out the plastic ridges in the motor block.