Tuesday, August 11, 2015

GBW 7080 - Part #2

This and successive postings of this title will follow the project to convert this 2-rail Atlas Trainman model of a ACF 50' boxcar lettered for the Green Bay & Western into a Proto:48 model.  See Part #1.

The first two items up for change are the couplers and trucks.  Choices for the couplers mentioned in the first post included Type 'E' models in delrin from San Juan Car Company or in brass from Protocraft.  The trucks are easy to modify (narrow) with drop-in bolster replacements designed by Jim Lincoln and produced by Shapeways.

Couplers:
I ordered one of each type of coupler kit offered by San Juan, with the difference being the "scale shank" versus one that fits in a Kadee coupler box.


Unfortunately, that means it doesn't fit an Atlas coupler box.   Plus, they are difficult to assemble to a reliably operating state.  Of the two-and-a-half I've put together so far, the first was a dud because what looked lie flash was mistakenly trimmed off and this rendered the coupler unlockable.  After replacing this part, it now one works OK and holds under a moderate load against another coupler, but the other one doesn't remain locked either (for a different reason).

The "scale shank" ones yielded slightly better results.   Out of the package, they looked more cleanly molded and sharper.  Maybe because I knew more about what to do, they went together more smoothly, but some of the same operating reliability challenges were still there.   Perhaps after a dozen pair of these I could get the hang of it.

The couplers from Protocraft come assembled and work right out of the box.  There are few subtle differences between these and the SJCC version, with the Protocraft ones looking just a bit bigger.   They come with the bottom lift pin mechanism already in place.   I'll post more updates when I get these mounted on a freight car and hopefully operating with the lift bar.

Here's a rather poor comparison photo of all four couplers. From left to right, you have Atlas Original, SJCC "standard", SJCC scale, and Protocraft.

In summary, with the Protocraft couplers starting out reliable and coming with coupler boxes, I'm leaning in that direction for general usage.   They are about three times the price though.

Trucks:
The first 3D-printed parts arrived that I ordered arrived and the use of the "black strong-and-flexible" material seems to be a good choice.  They cut away from the sprues cleanly and the finish somewhat resembles what a rusty metal underframe would look like.  Of course, one does not see much of the bolster itself in a model siting on the tracks, so the point is: they don't distract.

However, I'm again waiting on more parts from Shapeways, as the first two I ordered were for the newer style Atlas trucks, whereas the model I have has the older style trucks.  According to Mr. Lincoln, the difference is the width of the sideframe: Newer ones are 1/8" and older ones are closer to 3/16".

I put the Protocraft wheels in one truck anyway just to see what they'd look like and I am impressed.  There's some slop in them but that is due to the sideframe difference noted earlier.

The inability to immediately assemble the trucks with the narrowed bolster prompted me to think about freight car trucks in general.  The Atlas ones are a rigid frame design and based on some Proto:87 experiences of another modeler I read about, it got me thinking that I should probably seek out a fully sprung truck to hopefully better navigate the track.

Now that's mostly forward thinking because I don't actually have any track yet to run this car on and at the rate things are going it'll be a close race between the cart and the horse -- maybe I'll get a test track section built before winter arrives.  Nor do I consider that one source a doomsday scenario -- but P:48 is the same proportions as P:87, so flange depth and tread width are important concerns -- and I want to model rickety industrial track.  I'll have mass on my side though; O scale equipment is easier to weight down.

The conversation on the sprung trucks comes from the 'p48_modeler' Yahoo group.  An interesting read if you have the time and interest.

Future:
The latest Model Railroader magazine contained an article on modeling left over dunnage and generally sprucing up the interior of a box car.   I think I will follow some of those recommendations for this model, since it already comes with movable doors.