This page was originally compiled (from posts to this site) as an appendix to my OO book, and is presented here as bonus content.

Besides the electrical issues common to all old model trains, the one very specific issue that will confront anyone who wishes to operate vintage American OO gauge models today is that of getting Scale-Craft trucks operational.

Practically everyone who has tried to run any OO gauge models since 1937 has made some use of freight cars with Scale-Craft trucks! They were produced in large commercial quantities, and at least half of the cars in my collection have these trucks. Those on the layout have been worked over to varying degrees to get them in shape.

Bolster issues
Two of the most common problems are with the bolsters, both of the problems being illustrated in this first photo.

The problem on the right is fixable. Note how the side frame is tipped in relation to the bolster. In his article “A Fix for Scale-Craft Trucks” that was published in the May, 1994 issue of The OO Road Bill Johann recommended the use of what he called bolster shims. These you would insert between the end of the bolster and the side frame, down in the pocket it fits in, to keep things square; the thickness will be in the .015-.025 range. This can help a lot, keeping everything square.

On the left, we have a bolster that has shrunk. I would say roughly ¼ of all the Bakelite Scale-Craft truck bolsters show some evidence of this shrinkage. For this problem in reality there was, until recently, no good fix.

A 3D printed solution
However, there is a great fix now; the bolsters can be replaced with the 3D printed reproduction bolsters, which are sold on Shapeways. The seller there is JeffsOO (Jeff Barker). (And while you are there, check out what else is produced in 1:76, there are many interesting products on Sapeways. Most notable among them in recent years have been a series of locomotive shells done by two different sellers, including for American OO EMD SW7, GP20, and SD24 models, and an Alco FA).

Building them up is straightforward. After cutting them off the sprues the first step is to drill out the holes. The end holes you need to drill out with a number 50 drill. Next, you need pins. Depending on the old bolsters you have on hand, these will be easy or not so easy to harvest, but all you have to do really is use pliers and break them out of the Bakelite, which if you are lucky will eventually shatter and crumble, but oftentimes has a tar-like texture. Eye protection being a very good idea, too.

The JeffsOO bolster as produced matches the Scale-Craft bolsters in size exactly. However, in many situations a bolster that is a little longer is handy. As a result, most of these that I have built up I have put a small washer on with the pin to extend the width of the bolster. It is actually a washer that S-C provided in their kits, I have quite a few around. Thin plastic stock would work as well.

The pin itself you press into place with large pliers. Try not to put them on too far! They are really hard to pull out, but clearly are not going anywhere. Placed correctly the sideframes will be held in place very squarely.

I have been able to build a number of trucks up fairly quickly. These bolsters will really solve some problems. One type of truck in particular, S-C 4-wheel passenger trucks, they need very long and very square bolsters to roll well, and these will certainly help these cars out. They will help out any S-C truck! I am very pleased with every truck I have rebuilt so far.

One other thing worth noting, in a lot of situations with non-S-C cars you need to use a screw bigger than fits in the hole in a S-C bolster. Back in the day people drilled them out, but I hate to try to modify original Scale-Craft bolsters at this point (for fear of breakage), so this was a big issue. With these new bolsters, drilling the screw hole bigger is not a problem at all, you can use a very large screw if needed and even countersink the head. The material itself drills easily and is very strong.

Rolling more freely
Another issue is even with a good bolster many S-C trucks do not roll well, and on a heavy car that is really a problem. Besides bolsters, the principal problems are with the axle holes. These may need re-drilled slightly bigger and or deeper. Bill Johann recommended a .070-.073 diameter drill; I use a #51 drill. You may want to also chamfer the holes and blow in some powdered graphite as well. If things still are not working, a little light oil on the bearing can also help.

A secondary problem can be the bolster clip; the longer tab can interfere with the wheel sets. These Johann recommended trimming the part of the clip that can hit the flange to a 30-degree angle.

Wheelset variations
Scale-Craft marketed at least three distinct types of freight car wheel sets, two of which are illustrated here.

By far the most common type is on the left, brass wheels with the split axle. Some examples of this type were also made with steel wheels. This type of wheel will work very well if the gauge is right. To check the gauge, use a NMRA On3/OO standards gauge and get them in line. This gauge was introduced in 1981 and is indispensable for the OO gauge operator.

Another reason to use the standards gauge is there are non-Scale-Craft wheelsets that have the look of Scale-Craft, especially Nason 2-rail wheelsets. The Nason ones have more variable wheel treads and need to be examined carefully before putting in service.

The truck on the right in the photo has wheel sets that are not brass but rather are Bakelite. The treads are slightly wider, and this type tracks well. I would like to say these are from very early Scale-Craft production, but the very first advertising shows that their trucks were produced with brass wheels. This type of Bakelite wheel is the same as was shipped out in the lead truck of their 4-6-0, and they may have gone out on freight trucks as a WWII era substitution.
The final wheel type is in the last photo, with a solid axle insulated on one side, from late Scale-Craft production.

These have a couple different issues that have led me to ban them from my layout. One is that the treads have more variation, some are well undersized. The other is as they have a solid axle. Why this is a problem is that they are insulated on one side, and with the truck equalization there is some flex and they will short out intermittently. Scale-Craft trucks were really designed for wheelsets that were insulated on both sides.

Final notes
Scale-Craft and Lionel used far better machinery and cutters to make their wheelsets than any of the other early makers. Even then, they earned over time a bad reputation over time with operators, due to the issues noted above. The good news is that if you invest a bit of time and set them up right you will find they are pretty bullet proof and operate flawlessly on decent track.

Among all the cars in your collection you may find some Scale-Craft trucks upgraded with Ultimate wheelsets. As nice as they are, they can have a slight tendency to short, and I have come around to it being a good idea to just convert these trucks back to original Scale-Craft wheelsets with the split axle. They are completely reliable in any S-C truck, use the Ultimate wheelsets in a Nason truck instead.

One curiosity I should mention is that Scale-Craft 6-wheel passenger trucks typically will work fine with shorter bolsters than on the freight trucks, so you may find it useful to switch around bolsters. Also another quirk is a solid axle wheelset will work pretty well in a 6-wheel passenger truck, as it has less flex than the other designs. But, by the same token, solid axle wheelsets won’t work well at all in Scale-Craft 4-wheel passenger trucks, they flex too much and will short constantly. Use original Scale-Craft wheelsets with the split axle in those.

Finally, the depth of the axle holes will vary (likely they vary by production runs), so do always double check how deep the holes are for the axles, they need to all match for trucks to operate reliably. Happy operating!