I made one of those “Spur of the moment” impulse buys on the weekend. It all happened when I rushed out to my LHS to buy a bottle of Realistic Water for my pond. I grabbed the RW off the WS display and headed for the cash when this red and black monster beckoned me. The monster I speak of is really just a small CNR GP9M by Walthers Trainmaster. I had the cash on me, and in a rare moment of not caring what my would say, I bought it.
It’s a nice little loco. Runs pretty smooth and for the price the detailing is good. I have one minor problem with it…
In one of my 20" radius turns (I know it’s small, bare with me) it occasionally hops it’s forward left wheel to the outside of the turn. Not everytime, but regularly. All of my other loco’s function fine over this section and NEVER derail. Any ideas as to why? Wheels out of Gauge on one axle? Is that possible? Other ideas? …and remedies?
Yes,the wheels could be out of gauge or something could be binding causing the truck to derail…
I see no real reason why that Geep can’t go around a 20" cure…It should be able to take a 18" curve just like the Athearn GP7.[:D]
yep…sounds like the wheel is out of gauge…i’d go back to the LHS and purchase an NMRA gauge and check the wheels…Athearn is real good at having this problem right from a new box…i’ve had three Athearn locomotives in the past do this and it’s as simple as gauging them and positioning the wheel back into gauge…two of them were Athearn GE U33C’s…both were out of gauge from the box and another was an Athearn GP-9 some years ago…chuck
The next big question is…Once I get the gauge and confirm that the axle is out of gauge (which I am sure it is)…How do I set the gauge on that axle? …or any other axle for that matter. Is it a matter of replacing the axle, or fill in the blank?
Assuming the axles are put together in the same way as the Athearn ones (with two stub axles pressed into a gear) you can just gently press them closer together by hand. If there’s a solid axle then try gently twisting the wheels while pressing them closer together - it will probably only be a mm or two out. You can also use a micrometer to check back-to-back gauge - I set mine to 14.5 mm which seems to be the best for Peco track - they recommend this and I’ve had no derailments. NMRA gauges are a bit tricky to come by over here but Peco’s measurements seem effective enough.
I had the same derailment problem with an Athearn Genesis SD70. The problem turned out to be caused by the trucks binding as they entered the curve and a slight dip in the outer rail about halfway around.
Get a good, small spirit level that you can set across your rails and run it around your curve to check for slight dips or rises in one rail. Then check the locomotive trucks’ ability to swivel freely as it enters a curve. Sometimes there’s a small amount of flash on the trucks or locomotive shell that can cause them to bind.
As others have recommended, get a NMRA gauge and check the wheels, too.