So I finally have a follow-up to my earlier posting of 9 July where I was about to release an NYC L3a 4-8-2 Mohawk locomotive for service at Fillmore.  Just at the last moment I discovered a cyclical hesitation in the driving mechanism at very, very slow speed.  In that post (LOCOMOTIVE TUNING PT1), I went through all the checks I made to diagnose the trouble.  I concluded that one or more of the drivers might be out-of-quarter, and so I went about obtaining the tools and knowledge to check this – see category TECH – TOOLS: SENSIPRESS+, QUARTERER 2, RE-QUARTERING WHEELSETS.

Well I checked all the drivers and…….they are in quarter!  A bit disappointing since I was hoping to find a fault and then correct it.  But those babies are in proper quarter and I am left wondering what could be the problem.  Perhaps the wheels are not round or an axle is slightly bent.  These could be a cause of trouble, but in my view, they are very unlikely.  Even if this is the problem, I cannot properly check for it nor correct it anyway.

As the wheels were in quarter, I did not dismount one wheel each and re-quarter them.  I did check the gear by placing that driver in the quarterer 2 without crank bushings and resting the axle on the cut-outs in the axle carrier plates.  I then drew a line (~1/2″) on a piece of paper using a straight-edge.  I placed the Quarterer 2 on this paper and aligned one side of the gear to the line on the paper.  I then rotated the wheel set while observing for any wobble versus the drawn line.  Although this method is not the most accurate, the gear looked very good.  I also very carefully checked the condition of the gear teeth (again), with no fault found.

Near the end of my rope, I decided to try to install the drivers in different positions.  However, the only swap I could make was driver 1 with 4 because driver 2 must stay in place (it has the crank connection for the main rod) as well as driver 3 (it has the gear for the motor).  I applied Nano Grease to the gear box, reassembled the locomotive and ran her through Fillmore.  While not ultra smooth, the result is a better running model at very slow speed than before and I know when to call it quits and take what I can get.  Fillmore is far from perfect.  I’m far from perfect.

NYC 3004 is currently in the paint shop getting a refresh due to the much handling it received during trouble shooting.

I hope you will indulge me a little more….

I think this really all comes down to self-reliance.  As model railroaders, our most valuable tool is self-reliance.  The more we can fix (or try to) the better off we are.  We’ve all been disappointed by poor quality, where warranties are meaningless.  In the end, it is up to us to make things right.  While some things seem like they are way too complicated to correct, they often are not.  I now have the confidence to understand the design of steam locomotive models.  They are not difficult, but when one does not know about steam locomotive models, they look like they need an expert to repair them.  While I may not be able to straighten axles or true wheels, I can at least try to find the problem.  Way more often than not, it is something that is correctable.  No regrets on the expense in time and money spent on the quartering tools; I learned a lot and feel a bit more complete as a railroad model hobbyist.

NYC 3004 will be ready for service – I’ll make a post on that soon.