My first design for the cylinders made the end caps too thick. Six inches felt good at the time, but when I finally dropped a cylinder to the Assembly view in OnShape, I found the steam chest would overlap the end caps.
Sadly, I saved that little virtual test until after I had finished the first cylinder. That was when The Girl came into the workshop to see what I was up to, and when I would be ready to play with her.
She listened patiently to the whole sad tale, but her eyes lit up when I suggested we make the discarded cylinder into a secret compartment bead. So, we soldered the looser end on, and the other end is a light friction fit.
Being brass, it has a steampunk vibe, and makes me wonder what other engine parts could be turned into accessories. Driver buttons? Headlight rings? Dangly connecting rod earrings? Air pump cuff links? Soon everyone will want this stuff!
Pembroke:87 
I was helping staff put away Christmas ornaments and held one up to my ear. “Is this too gay?”
One of the women looked up and said, “No, just enough”.
All the men there were gay so she must have assumed … lol
Now, how about marker lamps as earrings?
Marker lamps in HO are pretty small, even for earrings, but maybe O scale ones would work. However, I like dangly ones better.
When you modelled everything up in Onshape did you do up a full set of drawings for v1 or are you primarily relying on the assembly module to figure things out while you make revisions? For my machining and assemblies I do drawings so I know what to do at the machine/when I’m programming but I’m pretty lazy with printed parts.
AH
Hi Andrew, I only do drawings of parts I need to fabricate. It’s a waste of time for anything that will be made by automation.
Interesting side note: I have a friend who is building a prefabricated home. The company that makes the panels is happy to work from the 3D model, but the engineering company converted the whole model first into 2D, with all the attendant errors and version issues. That is surely borderline negligent in this day!
Happy machining!
Rene