The online magazine on the history and operation of vintage scale model trains in American OO gauge

Thursday, July 2, 2009

Keys to tuning up Nason OO trucks

New wheelsets, square bolsters, and a little luck.

One of my projects now is to return more of my “vintage” OO gauge models to layout worthy (operable) shape, as in put them to the point that I can run them reliably on the layout. I would like eventually to get every model that I have out on display up to a reliably operable condition. Related to that, there is a category of very special knowledge that is pretty inside stuff, you have to really be deep into the topic to want to figure it out even. In American OO how to tune up Nason trucks is one of those topics.

I have for some time had a couple cars on Nason trucks that ran fine but they came to me on modern, RP-25 wheelsets so why they ran fine seemed no big mystery. Another car also ran fine with what appeared to be the original wheelsets. And then we have the few other Nason cars in my collection. One I had invested a lot of time in to rebuild carefully and it was hopeless, that car would derail literally every time around the layout in the turnouts.

The wheels were in gauge. The only real clue I had was from the late Bill Johan. Back in this post I quoted him from the May, 1994 issue of The OO Road where he indicated what types of OO trucks he used on his layout for operation: “…I’m sort of fussy—Scale Craft (reworked extensively…), Lionel, or Nason with the square bolsters only, if you please.”

In looking closer, I found that the one car that ran well with what I thought were all-original Nason trucks had Scale-Craft wheelsets! And I found that another pair of trucks I had that were not mounted on a car but tested well had modified Lionel wheelsets! It looks like a predecessor took three-rail Lionel wheelsets and cut them in half (!) and put them on Nason sub-axles to make two rail wheelsets. In other words, a couple modelers before me figured out the same thing. One secret to running Nason freight car trucks is new wheelsets.

Nason wheelsets must have run on the layouts of Hugh Nason and his friends just fine. For me they are very touchy. The the flange is often somewhat sharper with less of an angle toward the tread compared to a Scale-Craft wheelset, but the big problem is the width of the tread itself being variable and probably a bit narrow.

In the photo we have a "rogues gallery" of Nason trucks. Starting clockwise from the top we have on the caboose U bolster trucks that have been modified with Lionel wheelsets, a stock square bolster truck, a square bolster truck modified with S-C wheelsets, a stock U bolster truck, and finally another U bolster truck on a Picard covered hopper with S-C wheelsets. Click on the photo for a larger view.

Nason wheelsets look similar to most Scale-Craft [and Graceline] wheelsets but the sub-axle may be “heavier” looking (they used two types) and the face of the wheelset is more curved than any version of S-C. The flange difference is subtle but my turnouts "see" tread width variations clearly. [And I have actually noted at least five different styles of S-C freight car, split axle wheelsets! All track just fine for me through my Mantua turnouts. Graceline is another story, more on that in a future post.]

The other part of the problem is the bolsters. Johann preferred the square bolster version of Nason trucks. Actually, for sure Hugh Nason himself was a three rail operator and I strongly suspect their trucks set up best for three rail use with the cast bolster. The U shaped fiber bolster for two rail operation can get out of square pretty easily and the solid square ones are not all perfect either. The sideframes being bronze are also not easy to work with if they are out of alignment at all.

I was able to get one pair of square bolster trucks set up really well with Scale-Craft wheelsets. That is what will stay on the boxcar that I rebuilt, seen in this last photo. As for the rest of the Nason trucks I tried to work on, it was a bit frustrating. I could not get any one pair to operate well with S-C wheelsets due to issues with bolsters and getting everything square. Not my lucky day.

In the end I have several pair of Nason trucks that are all original and complete and on vintage Nason cars that can’t be operated on the layout. I would prefer they be operable, and they would be actually if I had no turnouts, but at least they are complete cars with matching trucks and represent the output of this classic OO maker well.

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