Work continues on the Viewliner, with the car connection integration and articulation being the main driver for the workflow. Everything seems to be working in theory and through some physical print tests, the results are falling into place. 

The articulation is by far the trickiest part of the project, keeping everything aesthetically pleasing while being practical and having the train actually negotiate the curves specified. The passenger cars had to be developed a lot further since the articulation workings will dictate the car design, potentially visually too. This was very challenging, keeping track of pivot points, trucks centers, car clearances and keeping a close eye on material thickness. 

While the Viewliner at a glance may seem like "a locomotive and passenger cars" the miniature version has a couple different model designs that make up the train:

• Locomotive
• Car A (peg coupling into back of locomotive)
• Car B (hidden peg coupling between cars
• Car C (same as Car B, just with "Observation car" detail on the end)

Locomotive, Car A and Car B

The connection between the locomotive and Car A is unique to the rest of the train because of the motor block issue; if it wasn't there, the connecting point would have been hidden in the diaphragms like the rest of the cars. Here the connection works as a peg from Car A resting into a pocket on the back of the locomotive.

And here it is in practice; I'm printing prototypes on my own machine to dial in details and make corrections in the files on the fly. 

The recessed area for the trucks on the passenger cars took some time to work out. By about the 4th physical print test everything seemed to shape up and function correctly. I'm relying heavily on slop tolerance in the trucks to help negotiate the curves. Won't really know until it's running on the test track. 

I'm quite pleased with how the connection design for between the passenger cars worked out; there's a satisfying 'clink' when they go together!

And lastly here's a look at the prototype cars/locomotive put together on the desk. Pencil for scale. Unfortunately there's not much I can do on the car design for now; I need more trucks in order to do testing and COVID-19 has closed up the Bachmann parts store! Boo! But luckily with articulation somewhat figured out and in theory works on the physical version, more can proceed on the locomotive.