Need some ideas to improve pickup from Kato Mikado tender trucks

[mmagliaro]

Glad you got it working.  Yes, cleaning the wheels is something that I admit I often overlook on those
tenders because they have such a reputation for being so good.   I become accustomed to expecting them
to work even over very dirty track because they are so good at wringing every possible bit of pickup
out of a bad situation.    I ran an engine with the earlier generation Con-Cor/Kato trucks at an NTrak show once. 
It used trucks from the 4-6-4 with the sled plates, not the axle-end pickups.  While that one is not quite as good,
it is still terrific and uses the same basic design of the truck tangs pushing up on bronze strips in the tender floor.

They were 6-wheel trucks.  But after one pass around the whole layout, the engine started to sputter and lose contact
badly.   It was hard to believe, but all 12 of those tender wheels were covered in so much crud that they simply could not
pick up power anymore.

Yep.  Clean wheels are always the place to start.

[randgust]

I had a REALLY cruddy set of Kato caboose trucks that I got secondhand, and did the felt wheel test with the dremel.  This set was going to get tossed if I couldn't get it clean.  I was so astounded how well it worked I repeated the process on every Kato free-wheeling wheelset I own, and with my cabooses, critters, and tenders, that's quite a collection of wheels.

I thought that at some point I was going to have to restart the ultrasonic cleaner to do this but wow, this just worked so well.   It's way easier and less stressful a method of wheel cleaning than I've found for anything else.   I could get powered axles clean, it was the free-rollers that I couldn't.  This 'should' work for any metal wheelsets that can take the speed and force - I would not recommend this on metal wheels in a plastic sideframe.

Oh, and don't kid yourself - end-axle pickups do get dirty inside.  The sparking makes carbon which makes dirt.  So the conductalube is an important part of that to lubricate and polish that during the high-speed spin.  At least in HO I've seen end-axles chew all the way through the pickups due to wear.   I always used conductalube, but safely polishing the treads back up was a mystery.

[brokemoto]

The numero uno enemy of N scale equipment is D-I-R-T .  I have found it to be the cause of numerous operating headaches from poor locomotive performance to derailments.  When something starts to go badly on my pike, assuming that I have on my thinking cap, the first thing that I do is check for dirt.

Call it 'crud', 'gummy', grease, muck, caking or whatever; it is ALL dirt.  Yes, excess caked crud on your boxcar wheels CAN make them derail, especially on turnouts and diamonds.

Obviously, when I posted my first reply to this topic, my thinking cap was not on.