Does the NMRA or anyone make a gauge checker for 3 rail 0. We have some issues with MTH 2-8-0’s front trucks jumping the track and we don’t know if the front wheels are out of gauge, or the switches or tracks are. So does someone make a standard to check both the wheelsets and the tracks? Thanks, Dave
It’s probably neither. And it may take federal grant money to find the exact cause, but it is probably a geometry issue combined with how the pilot truck is weighted/sprung and how it tracks through the switch & around curves. What kind of “switches or tracks” are you using? Radius? Where does the derailment occur?
Rob
Does it derail to the inside or the outside of the curve?
Try this website: http://www.internettrains.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=IT&Product_Code=NMR-5
This thread discusses the problems in trying to use an NMRA gauge with hi-rail & tinplate wheels. It’s just not a complete solution.
Rob
They are derailing on Gargraves switches or turnouts. Seems to be on the frogs. The particular ones it happens most on are R=72 and R=100. Dave
Does it derail to the inside or the outside of the curve?
If my memory serves me right, to the inside. Dave
If that is the case, there is a very good chance that your problem is due to a steering-geometry error common to most if not all Lionel locomotives with two-wheel pilot trucks. The pivot for the truck is located too far forward. The correct length of the truck’s tongue is
2
t = d/2 + w /8d
where w is the wheelbase (the distance between the axles of the front and rear drivers) and d is the distance of the pilot-truck axle from the center of the driving wheels. Notice that a locomotive with zero wheelbase would have its pivot exactly halfway between the pilot axle and the (single!) driver axle, and that having a finite wheelbase moves the corrent pivot point slightly to the rear of the locomotive. The value of t does not depend on the track radius.
If this is what is causing your derailments, the only sure cure is to create a new pivot and scab an extension onto the truck tongue. However, you may have some success with increasing the load on the truck, with spring or weight, and by eliminating any irregularities on the inside of the rails that the truck flanges can catch on to climb over the rail.