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Lately, I have come across three Hines Mikado chassis that all have driver shorts.  In one case it is a near new partially built un run kit.  See picture.  The picture with the leads on the main drive axle shows the short.  If the driver has preserved insulation, infinite resistance or very high resistance such as 10 Mega Ohms should be measured.  I have three other Hines Mikes and they are fine.  Never saw this problem in my Lobaugh, Scalecraft, Pearce, All Nation or Saginaw pieces.  From now on when I attend a show I’m bringing a Volt Ohm meter.  Also most of the time when one sees a short like this it is often from a metal brake shoe touching the steel tire which is why I like plastic brake shoes for my steam.

Another issue that I have seen is abnormally loose play in the axle probably due to worn out bearings.  Saw this in a KTM northern.  Good news is the KTM axle bearings are easy to find .  Recommendation: grap the drivers one axle at a time and twist horizontally as shown in the picture with the green arrows.

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@PRR Man posted:

I recall a recent topic (not on this forum) discussing minute pieces of metal bridging the tire to the wheel center on rim insulated drivers. is that how these drivers are done?

Good point.  The drivers are cast iron.  Thinking that some oxidation may be bridging the insulation to the tire.  Another person thought it may be some water in the insulation paper, presuming they used insulation paper.

I have an LCR meter also, but does it read the same short with a normal DVM on Ohms?  I see the display says 'R' and120hz,my thought is that if the insulators are wet from water or oil, it is appearing as a bad capacitor with the AC signal imposed on it. If they are conducting due to moisture, the wheel set in the oven at 200 degs for a couple hours would dry them out.

Last edited by CALNNC
@CALNNC posted:

I have an LCR meter also, but does it read the same short with a normal DVM on Ohms?  I see the display says 'R' and120hz,my thought is that if the insulators are wet from water or oil, it is appearing as a bad capacitor with the AC signal imposed on it. If they are conducting due to moisture, the wheel set in the oven at 200 degs for a couple hours would dry them out.

Also checked it with my VO meter and interestingly showed 1 ohm resistance.  Your point is well taken and thought about the oven approach.  Thank you for the advice.

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