Any tips for cleaning Kato passenger car wheel pickups?

[Simon D.]

You could try sharpening a soft pencil and twirling in the axle cup - this should improve connectivity and reduce friction - not sure if it attracts or repels dirt.

[Dwight in Toronto]

Here’s my two cents on flicker-free LED coach lights.

I’ve got a build thread underway in the “Weathering/Scratchbuilding” section where I’m rejuvenating and updating an old Bachmann Turbo Train:
https://www.therailwire.net/forum/index.php?topic=58350.0

One small part of that project was adapting the rear loco bogie for track power pickup, so as to illuminate a single red end-of-train marker LED.

With Peteski’s help, I made up a simple circuit.  Peter said that the 1000UF capacitor was overkill, and size-wise it’s a challenge for N scale, but it’s what I had on-hand. 

Suffice to say that the LED lights up, there is NO flicker whatsoever, and it remains illuminated for 26 seconds after track power has been removed.  Out of curiosity, I tried it with 3 led’s in series, and it worked just fine.

[peteski]

Problem with stock Kato lights is that in order to add anti-flicker circuit you have to splice it into the existing circuit board.  That requires some precision trace cutting and unsoldering/soldering.  I  have  designed such circuit for both  PC boards (one with resistor and one with constant current diode), but have not finished the write-up (the story of my life). 

Sounds like the lighting unit Jimbo mentioned might be an easier way to go.

[OldEastRR]

I get flicker on my KATO cars only from dirt spots on the wheel treads. I don't clean my track a lot between sessions, but then I found  some of my older non-lighted cars (both freight and pass) have packed dirt on them from years of running and not being cleaned. They were the guys dirtying up the rails, not so much dust or humidity.  I suspect that's why my track seemed to get dirty rather quickly.
The dirt spots on the treads aren't always dense blobs. They sometimes are a thin barely-noticeable streak along the tread, or even some itsy-bitsy speck. It may look at first glance the wheels are clean, but they aren't. But even w/ 8-wheel pick=up a couple of dirt spots interrupting power for even a moment will produce flickering.
As for the lighting itself, using DCC provides constant even illumination whether the train's moving or not. With DC, going slow means the lights are dim, moving fast gets them really bright. Does a capacitor solve the problem?
The thing to be careful about lighting cars w/ DCC is the amount of constant track voltage your system puts out. When running my incandescent bulb (v1.0 lighting kit) KATO trains on a club layout with Digitrax controls, the power was so high the bulbs got real hot and deformed the plastic above the bulbs. When I put an NCE system I still got warm incandescent bulbs but not hot enough to melt the car's plastic. (Now KATO lamps are cool LEDs) Which worked out well for my purposes as I could mix the lamp types from car to car for different spaces. So I can get warm filament bulb, bright fluorescent or muted fluorescent LED lighting effects in the same train. (KATO made 3 versions of its lighting kit)
I've cleaned the axles cups on locos a lot, but never have found the need to do my pass cars.

[Chris333]

Not my idea, found the pic online.

[OldEastRR]

I was wondering what to with this thing the dentist gave me!!

[nkalanaga]

I do floss my teeth, but have never tried one of those, or been given one by my dentist.  Surprisingly, I see a lot of them discarded in the employee parking lot at our auto-parts factory.

I, and the hygienist when I have my teeth cleaned/checked, just wrap the floss around two fingers and go at it!

Never though to try one for cleaning truck pickups.

[Dwight in Toronto]

A lot of floss is “waxed”, so who knows what detrimental remnants THAT might impart.

[nkalanaga]

All of mine is.  My teeth are close enough together that it's almost impossible to floss them with unwaxed floss.

Incidentally, I've been using dental floss to sew buttons back on shirts for the last 50 +/- years.  Once on, the shirt usually wears out before the button comes off again.